Forest Research Technical Report - British Columbia · 2007-02-25 · TR-017 Ecology March 2002 Technical ReportForest Research Vancouver Forest Region 2100 Labieux Road, Nanaimo,

TR-017 Ecology March 2002

Technical ReportForest Research

Vancouver Forest Region2100 Labieux Road, Nanaimo, BC, Canada, V9T 6E9, 250-751-7001

An Operational Trial to Evaluate the Effectivenessof Using Modified Bucking/Yarding Practices

in Coastal Old-Growth Stands to MaximizeCoarse Woody Debris Levels in the Setting:

Establishment Report

Prepared byG. Davis and A. Nemec

for the Vancouver Forest Region Coarse Woody Debris Working Group

Research Disciplines: Ecology ~ Geology ~ Geomorphology ~ Hydrology ~ Pedology ~ Silviculture Systems ~

Gerry DavisResearch EcologistVancouver Forest RegionBC Ministry of Forests2100 Labieux RoadNanaimo, British Columbia V9T 6E9250-751-7001

Amanda F. Linnell NemecInternational Statistics and Research Corp.PO Box 496Brentwood Bay, British Columbia V8M [email protected]

Davis, G. and A. Nemec. 2002. An Operational Trial to Evaluate the Effectiveness of UsingModified Bucking/Yarding Practices in Coastal Old-Growth Stands to Maximize CoarseWoody Debris Levels in the Setting: Establishment Report. Prepared for the Coarse WoodyDebris Working Group. Research Section, Vancouver Forest Region, BC Ministry of Forests.Nanaimo, BC. Technical Report TR-017. 64 pp.

http://www.for.gov.bc.ca/vancouvr/research/research_index.htm

Technical Report TR-017 March 2002 Research Section, Vancouver Forest Region, BCMOF

Research Disciplines: Ecology ~ Geology ~ Geomorphology ~ Hydrology ~ Pedology ~ Silviculture ~ Wildlife

TABLE OF CONTENTS

EXECUTIVE SUMMARY ................................................................................................................................................................... 3KEYWORDS ........................................................................................................................................................................................ 3ACKNOWLEDGEMENTS .................................................................................................................................................................. 3

1 INTRODUCTION ............................................................................................................................................................................. 4

2 OPPORTUNITY TO MAXIMIZE CWD RETENTION AT THE TIME OF HARVEST ............................................................ 5 2.1 Potential Sources of CWD ........................................................................................................................................................ 5 2.2 Options for Maximizing CWD in the Setting, Post-Harvest .................................................................................................. 7

3 STUDY OVERVIEW: MODIFIED BUCKING AND YARDING PRACTICES ............................................................................. 8 3.1 Overview ................................................................................................................................................................................... 8 3.2 Study Objectives: Economic and Dead-Wood Components .................................................................................................. 8

4 PROJECT DESIGN AND IMPLEMENTATION ........................................................................................................................... 9 4.1 Site Selection ............................................................................................................................................................................. 9 4.2 Site Description ........................................................................................................................................................................ 9 4.3 Stand Description ...................................................................................................................................................................... 9 4.4 Layout ........................................................................................................................................................................................ 9 4.5 Bucking and Yarding Practices .............................................................................................................................................. 11

5 METHODS ..................................................................................................................................................................................... 14 5.1 Definitions ............................................................................................................................................................................... 14 5.2 Cruise Measurements ............................................................................................................................................................. 15 5.3 Measurements of Coarse Woody Debris and Stumps ........................................................................................................... 15 5.4 Site Index and Tree Age .......................................................................................................................................................... 16

6 ANALYSES ..................................................................................................................................................................................... 17 6.1 Pre-Harvest Analyses .............................................................................................................................................................. 17

7 RESULTS ........................................................................................................................................................................................ 19 7.1 Selection of CWD Diameter and Length Classes .................................................................................................................. 19 7.2 Site Overview .......................................................................................................................................................................... 20 7.3 Operational Cruise Summary ................................................................................................................................................ 21 7.4 Total Gross Site Volume, by Stratum and Log Grade .......................................................................................................... 23 7.5 “Potential” Sources of Post-Harvest CWD: Attributes of Pre-Harvest CWD and

Low-Value/Non-Merchantable Wood in the Stand ................................................................................................................... 24

8 DISCUSSIONS AND CONCLUSIONS.......................................................................................................................................... 29 8.1 Potential Sources of CWD ...................................................................................................................................................... 29 8.2 Block Comparisons ................................................................................................................................................................. 33 8.3 Literature Comparisons for Dead Wood .............................................................................................................................. 33 8.4 Post-Harvest Surveys ............................................................................................................................................................. 35 8.5 Towards the Development of Quantitative CWD Management Guidelines: Future Survey Needs .................................. 36

9 LITERATURE CITED .................................................................................................................................................................. 41

10 GLOSSARY.................................................................................................................................................................................. 43

APPENDIX A. DEFINITIONS OF SPECIES-SPECIFIC COASTAL LOG GRADES ................................................................... 45

APPENDIX B. OPERATIONAL TRIAL TO EVALUATE THE USE OF MODIFIED HARVESTING PRACTICES INCOASTAL OLD-GROWTH STANDS TO MAXIMIZE COARSE WOODY DEBRIS LEVELS: DESCRIPTIONS OFTHE BUCKING, YARDING, AND LOADING PHASES .......................................................................................................... 48

APPENDIX C. SUMMARY OF CWD DENSITY AND VOLUME STATISTICS FOR BOTH STUDY BLOCKS,USING LENGTH AND DIAMETER CLASSES FROM THE LITERATURE ....................................................................... 64

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TABLESTable 1. Utilization, as per cutting authority, for harvesting operations in Coastal British Columbia .................................................... 6Table 2. Timber utilization policies: Avoidable Waste Benchmark volumes ........................................................................................... 7Table 3. Stand statistics: Operational Cruise Summary ........................................................................................................................ 10Table 4. Broad timber types found at the study site ............................................................................................................................ 12Table 5. Areas corresponding to site, Wildlife Tree Patch, and yarding method, by study block ....................................................... 12Table 6. General schedule of activities ................................................................................................................................................. 12Table 7. Summary of pre-harvest strata ................................................................................................................................................ 15Table 8. Definitions of tree classes used by Weyerhaeuser and the BCMOF ...................................................................................... 16Table 9. Compilation piece definitions ................................................................................................................................................. 17Table 10. List of attributes used to compare the study blocks prior to harvesting, and corresponding units of measure ................... 18Table 11. Comparison of total gross volume/ha of windfalls for Tree Class C: cruise taper equation versus Smalian equation

of piece within plot ....................................................................................................................................................................... 18Table 12. Cumulative distribution frequencies for CWD length ........................................................................................................... 19Table 13. Cumulative distribution frequencies for CWD, large-end diameter ....................................................................................... 19Table 14. Diameter and length classes for specific cumulative percentiles .......................................................................................... 20Table 15. Examples of diameter classes used in the literature, and the corresponding cumulative diameter distribution

percentages based on study results ............................................................................................................................................. 20Table 16. Total site density, by stratum ................................................................................................................................................ 21Table 17. Total gross site volume, by stratum ...................................................................................................................................... 21Table 18. Gross cruise a volume, by tree class and log grade: both study blocks combined ............................................................... 22Table 19. Cruise net volume, by tree class and log grade: both study blocks combined ..................................................................... 23Table 20. Market value, by tree class and log grade: both study blocks combined ............................................................................. 24Table 21. % of total market value, by log grade and tree class: both study blocks combined ............................................................. 24Table 22. Total gross site volume and net site volume, for all strata combined .................................................................................... 24Table 23. Total gross site volume partitioned, by tree class, stratum, and log grade: both study blocks combined ............................ 25Table 24. % of total gross site volume, by stratum and log grade: both study blocks combined ........................................................ 26Table 25. Density of CWD, partitioned by diameter and length classes .............................................................................................. 27Table 26. Volume of CWD, partitioned by diameter and length classes ............................................................................................... 28Table 27. Density of CWD, partitioned by diameter and decay class .................................................................................................. 29Table 28. Volume of CWD, partitioned by diameter and decay classes ................................................................................................ 30Table 29. Density of “potential” logs in standing trees, by log grade and study block ....................................................................... 31Table 30. Volume of “potential” logs in standing trees, by log grade and study block ........................................................................ 32Table 31. Potential large low-value/non-merchantable pieces in Tree Classes A, B, and D: differences in density and volume,

by study block .............................................................................................................................................................................. 33Table 32. Examples of total, old-growth, dead-wood volumes reported in the literature. ..................................................................... 34Table 33. Total pre-harvest dead-wood volume, partitioned by structures (s) and merchantability: Example Coastal Summary Table ... 38Table 34. Pre-harvest attributes and potential sources of large CWD: Example Coastal Summary Table ............................................. 39Table 35. Post-harvest CWD attributes for the dispersed stratum: Example Coastal Summary Table .................................................. 40

FIGURESFigure 1. Site overview ........................................................................................................................................................................... 9Figure 2. Conks .................................................................................................................................................................................... 11Figure 3. Frost crack ............................................................................................................................................................................. 11Figure 4. Windfall................................................................................................................................................................................. 11Figure 5. Well-Decayed CWD .............................................................................................................................................................. 12Figure 6. Site map (scale 1:5000)........................................................................................................................................................... 13Figure 7. Total gross site volume, by stratum and log grade. ............................................................................................................... 25

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EXECUTIVE SUMMARY

During helicopter harvesting of old-growth forests in CoastalBritish Columbia, two strategies have been successful in reduc-ing yarding and hauling costs and dryland sort accumulations.These two strategies involve the following modified harvestingpractices:

� Bucking on site to create higher value logs. In this approach,low-value/non-merchantable wood (e.g., Y and Z Grade) isbucked and left in the setting.

� Marking Z and Y Grade wood for the purpose of leaving onsite. A scaler marks low-value/non-merchantable wood withpaint after falling and bucking, but prior to yarding.

The added benefit of these modified practices is an increasedretention of coarse woody debris (CWD), as low value/non-merchantable wood is dispersed throughout the harvested set-ting rather than accumulating at roadside or being removed.

In 1999, a multi-year operational study was initiated to evalu-ate the logistics, feasibility, and success of transferring proce-dures used in helicopter harvesting to other harvesting sys-tems. The purpose of the study is to compare, for both con-ventional and modified harvesting practices, the operationalcosts as well as the post-harvest distribution and attributes ofCWD over a range of sites.

Before embarking on the multi-year project, a pilot study wasundertaken to evaluate the sampling protocol and the opera-tional feasibility of applying these modified practices to otherharvesting systems. The pilot site, chosen in 1999, was an old-growth site in the Montane variant of the Very Wet Maritimesubzone of the Cedar Western Hemlock biogeoclimatic zone(CWHvm2). This site was to be cable harvested. The pilot sitewas divided into two blocks, one of which was harvested byconventional means and the other using the modified practices.

The review of the pre-harvest timber and CWD attributes forthe pilot site indicates there is the potential to retain, at the timeof harvest, CWD volumes comparable to the total volume ofpre-harvest dead wood. It is expected, however, that only aportion of the total low value/non-merchantable wood vol-ume will be left on site due to various operational factors�even in the block where Y and Z Grades of wood are buckedoff at the stump and marked to leave.

The total volume of pre-harvest low-value/non-merchantablewood (standing and down) was not significantly different be-tween the two blocks. However, there were a few significantdifferences in the distribution of this wood, which may or maynot confound the detection of post-harvest differences. Total

volume/ha of CWD was the main significant different be-tween the two blocks. The significantly higher total volume/hafor the Mark-to-Leave Block reflects a higher density of larger-sized pieces. Further, the two blocks show a significant differ-ence in the distribution of pieces by decay class. The Conven-tional Block has a higher proportion of small to midsize piecesin the Well-Decayed Class while the Mark-to-Leave Block hada higher proportion of larger pieces in the Moderately Well-Decayed Class.

Data from the 2001 post-harvest comparison of the two blockswill provide an opportunity to evaluate the effectiveness ofusing the modified bucking and yarding practices to increaseCWD volume and maintain larger-sized pieces in the dispersedsetting. The comparison will also highlight difficulties in imple-menting these practices, and indicate the cost of implementingthe practices on an operational scale.

KEYWORDS

harvesting, mark-to-leave, coarse woody debris, coarse woody de-bris volume, log value, low-value wood, nonmerchantable wood,log scaling, bucking, yarding, costs, Coastal British Columbia

ACKNOWLEDGEMENTS

This project was undertaken under the auspices of the Van-couver Forest Region�s Coarse Woody Debris Working Group.Funding for the pre-harvest component of this project wasprovided by the BC Ministry of Forests and Weyerhaeuser�sBC Coastal Group.

The authors would like to recognize the interest and commit-ment of staff at Weyerhaeuser�s North Island TimberlandsDivision during the field operations. Weyerhaeuser staff in-volved in the various aspects of the project include: Allan Beise,Ray Sumner, Mazz Battistuz, Rob Kine, Adrian Stevens, DonWatts, and Norm Harben. Ed Redlin of Azmeth Forest Con-sultants Ltd. was instrumental in ensuring the modified buck-ing practices and marking components of the project werecompleted properly. Further, the project could not have beencompleted without the involvement, interest, and commitmentof Eric Phillips, Brian Bulley, and Craig Evans of the ForestEngineering Research Institute of Canada (FERIC).

The authors would like to thank the following reviewers fortheir insightful comments on various drafts of the report: P.Ott, D. Heppner, E. Phillips, D. Collins, N. Densmore, and J.Parminter. Kathi Hagan is gratefully acknowledged for the tech-nical editing and layout of this document.

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1 INTRODUCTION

Coarse woody debris (CWD) is an important structural com-ponent in forested ecosystems. The structural and functionalroles of CWD are multi-faceted. CWD provides critical habi-tat for a myriad of organisms, many of which are connectedby �functional pathways that are partially or completely un-known� (Torgersen and Bull 1995). Organisms linked to CWDinclude invertebrates, fungi organisms, many species of plants(especially bryophytes and lichens), and vertebrates (Maser etal. 1984; Harmon et al. 1986; Caza 1993; Bull et al. 1997).The amount, structure, and dynamics of CWD in forests canalso influence nutrient cycling and site productivity, soil stabil-ity, global carbon storage, and provision of biological legacies��allof which are structural and functional links between present andfuture forests (Hansen et al. 1991; Harmon and Chen 1991).

In British Columbia, the management of CWD is a legislativerequirement on private land, on a Tree Farm Licence or woodlotlicence, and on Crown land other than in a Wilderness Area.1

The Forest Practices Code of British Columbia Act requires CWDmanagement objectives to be established in Forest Develop-ment Plans2 and Silviculture Prescriptions3. Current CWDmanagement is tied to the BC Ministry of Forests� timber uti-lization policy (BCMOF 1997; Landscape Unit Planning Guide,BCMOF and BCMOE 1999). Based on the Chief Forester�s1996 impact estimates on stand-level biodiversity, CWD man-agement is to have no impact on operating costs or timbersupply4 (Forest Practices Code Timber Supply Analysis, BCMOFand BCMOE 1996).

While limited, available literature suggests that the long-termeffects of timber harvesting and silviculture practices on deadwood (standing and down) are a reduction in dead wood vol-ume and a reduction in piece size (Spies and Cline 1988; Spieset al. 1988; Maser and Trappe 1984; Carey and Johnson 1995;Reid et al. 1996; Green and Peterken 1997; Fridman andWalheim 2000; Anglestam 1977). These reductions are mostpronounced where there is a long history of forestry (Anglestam1977; Samulesson et al. 1994). For Swedish forests, Anglestam(1977) reported that dead wood comprised 30�40% of the totalwood volume in unmanaged stands and declined to about 20%after one rotation. After several rotations of intensive fibre ex-traction dead wood volume was reduced to about 1% of thetotal wood volume. Samulesson et al. (1994) similarly report smallamounts of dead wood and very few large-diameter pieces inmanaged forests in Poland, England, and central Sweden.

While the history of forestry activities is shorter in the PacificNorthwest, the projected scenarios are similar to those reported

for European countries. The continued loss of dead wood undersuccessive cycles of clearcutting was modelled by Spies andCline (1988). They predicted that snag and log abundanceswould be 30% of the pre-harvest level at the end of the first100-year rotation and 6% after the second. Inputs throughlogging slash and some dead tree mortality were included inthe model. During the second 100-year rotation of the simu-lated, manipulated forest, total dead wood decreased from 24tons/acre at the beginning of the rotation to only 5 tons at theend of 100 years, before harvest. This simulation producedfew or no large pieces (>50 cm diameter) over one or tworotations (Spies et al. 1988). Similar projections have been madefor eastern hardwood forests (Gore and Patterson III 1985;McCarthy and Bailey 1993).

In North America, available research results about the effectsof harvesting on CWD (down wood) attributes are varied.Reported changes in total volume/ha or biomass followingharvest include: increases (McCarthy and Bailey 1993;Torgerson 1999; Gore and Patterson III 1985) and smallchanges (Torgerson 1999; Lloyd 2001; Davis and Nemec 2001).In part, these differences reflect factors such as timber type,stand age, harvesting objectives, and prior disturbance history.However, the above studies consistently report a shift in piece-size distribution. Most studies report an increase in total piecedensity with reductions in diameter and/or piece length thatare related to harvesting (Gore and Patterson IIII 1985;McCarthey and Bailey 1993; Torgersen 1999; Davis and Nemec2001). Research of this type is limited in Coastal British Co-lumbia forests.

Owing to the sparse data about CWD in either managed orunmanaged forests, quantitative guidelines for its managementin British Columbia are currently unavailable. Guiding princi-pals and management considerations to improve CWD reten-tion within the context of BC Ministry of Forests� timber uti-lization policy (BCMOF 1997) are outlined in a recently re-leased short-term strategy for managing CWD (BCMOF2000d). According to this document, there is an urgent need toassess the status of CWD relative to current harvesting prac-tices, as well as a need to initiate pilot studies to identify andevaluate approaches for increasing CWD retention at the timeof harvest. Over the past few years, various projects havebeen initiated throughout British Columbia to address the short-fall in CWD data. Projects are varied in scope but include:

1. pre-harvest inventories of dead wood and/or CWD (e.g.,Davis et al. in preparation),

2. post-harvest inventories of CWD (e.g., Lloyd 2001),

3. research on specific wildlife habitat requirements (e.g.,Hartwig 1999), and

4. research on the feasibility of alternative approaches tomaintaining CWD in the setting through modified opera-tional practices (e.g., Huggard 2000).

The following is a report about the establishment of the pilotphase of a multi-year (replicated) study. The purpose of the

1 Forest Practices Code of BC Act, Provincial Forest Use Regulation,Sections 2(1), 4(a) and (b), and 7(1).2 Forest Practices Code of BC Act, Operational Planning Regulation,Section 18(1)(u).3 Forest Practices Code of BC Act, Operational Planning Regulation,Section 39(3)(m).4 The 1.8% timber reduction allocated to stand-level biodiversity in the 1996timber supply analysis (BCMOF and BCMOE 1996) was assigned to WildlifeTree Reserves.

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study is to compare the harvesting economics and the result-ant CWD attributes achieved through conventional operationalbucking and yarding practices to those achieved through amodified method that leaves low-value wood in the settingrather than at the roadside or landing. This report presents thepre-harvest dead wood results for the pilot study. A compari-son of pre-harvest and post-harvest data will be available inthe spring of 2002. The progress report for the harvestingeconomic component is available from the Forest EngineeringResearch Institute of Canada (FERIC).

2 OPPORTUNITY TO MAXIMIZE CWD RETENTION ATTHE TIME OF HARVEST

2.1 Potential Sources of CWD

Under the timber utilization policy for Coastal British Colum-bia (BCMOF 1997), potential sources of CWD that can beleft in the harvested setting without the forest company incur-ring monetary billing (Table 1) include:

1. Live Y Grade logs (recorded in Residue and Waste Sur-vey as avoidable and unavoidable residue).

2. Dead Y Grade logs from snags and down trees and CWD(defined in Residue and Waste Survey as Grade 5-DeadLumber Reject, but not recorded).

3. Z Grade or Firmwood Reject logs (defined in Residueand Waste Survey but not recorded).

4. X-Grade-and-better logs5 (recorded in Residue and WasteSurvey as avoidable waste if not retained for safety rea-sons). (Refer to Table 2 for information on avoidable wastebenchmark volumes.)

5. X-Grade-and-better logs (recorded in Residue and WasteSurvey as unavoidable waste if retained for safety reasons).

6. Dead down woody debris with size, quality, or decay fea-tures below the Z Grade criteria (not recorded in Residueand Waste Survey).6

7. Leave trees (dispersed/clumped) (not recorded in Resi-due and Waste Survey).

Technically, items 1, 2, 3, and 6 above are �optional� and canbe utilized at the discretion of the Licensee depending uponmarket conditions. The Cutting Permit may specify the utiliza-tion of Y Grade logs with certain attributes. Under this sce-nario, failure to utilize these logs will result in the Licenseebeing billed at a rate of $0.25/m3. On the Coast, this scenariois a special case rather than a rule.7 Item 4 is mandatory utili-

zation, but is not billed for the first 35 m3 in old growth nor forthe first 10 m3 in second growth (refer to Table 2). Item 5 isnot mandatory utilization. Item 7 regarding leave trees is dis-cussed below.

Log Grades. General definitions for the above log grades areprovided in Appendix A; for more detail refer to the ScalingManual (BCMOF 1999). Briefly, Live Y Grade logs are lowvalue and are used for pulp. This grade is not billed but ischarged to Cut Control, unless otherwise specified in the Cut-ting Permit. Dead Y Grade and Z Grade logs and dead downwood not meeting utilization standards are not monitored forutilization. Dead Y Grade logs can be greater than 50% sound,but, because of checking and rot, they are not recorded in aResidue and Waste Survey. The Z Grade log is generally lessthan 50% sound and has too much rot for use as pulp. Neitheris charged to the Cut Control. Utility-Grade-and-better logs(X-Grade-and-better logs) may be classified as either avoidablewaste or unavoidable waste. Avoidable waste is wood that meetsthe mandatory utilization criteria. In 1999, the benchmark avoid-able waste volumes noted in Table 2 were incorporated intothe timber utilization policy (BCMOF 1997) to mitigate lowmarket value for marginal timber. The benchmark avoidablevolumes are voluntary; they are not billed, but are charged tothe Cut Control. The other source of X-Grade-and-better logsis the unavoidable waste. Unavoidable waste consists of X-Grade-and-better logs that are left on site for safety or envi-ronmental reasons.8 This wood is charged to the Cut Controlbut not billed. The remaining dead down woody debris, whichhas no utilization value, is not tracked for either billing or CutControl purposes because it is typically well below 50% soundand has size, quality, or decay features that prohibit its useeven for pulp.

Leave Trees. Leave trees may be retained in the setting forvarious purposes including seed production, visual enhance-ment or to serve as Wildlife Trees. The retention of thesetrees is specified in the Silviculture Prescription and CuttingPermits. The retention of leave trees solely for CWD recruit-ment is not practised in British Columbia. Instead, CWD re-cruitment is indirectly linked to reserve strata such as WildlifeTrees (patches or individual trees) and Riparian ManagementZones. For example, a Silviculture Prescription may specifythat Wildlife Trees are to be retained�either dispersed through-out the cutblock or within a patch�with CWD recruitmentlisted as a secondary objective. The numbers and sizes of treesand associated volumes, all of which are important in deter-mining the quantity and quality of CWD, are not specified.Moreover, even though trees within existing reserves repre-sent a potential source of future CWD, they do not function as

5 BCMOF internal memorandum, from Janna Kummi (Assistant Deputy Minister,Operations Division) to all Regional and District Managers, re: Timber UtilizationPolicy; 20 January 1999.BCMOF internal memorandum, from Jim Gowriluk (Assistant Director,Resource Tenures and Engineering Branch) to All Regional Managers and AllDistrict Managers, re: Timber Utilization Policy; 22 January 1999.6 For the purpose of the pilot study, dead down woody debris has been assigneda Z Grade when it does not meet the criteria of a Y-Grade-or-better log.

7 Bruce Markstrom, Cruising and Waste Technician, Vancouver Forest Region,BC Ministry of Forests, Nanaimo, BC; personal communication, June 2001.8 There is provision within the Logging Residue and Waste Procedures Manual(BCMOF 2000a) to classify mandatory utilization logs which have been markedin the field to meet CWD objectives specified in a Forest Development Planand Silviculture Prescription as unavoidable waste. This wood would be chargedto the Cut Control but not billed (Forest Practices Code General Bulletin 33).

5



CWD until they are dead on the ground. If trees within exist-ing reserves are to contribute towards CWD, then a more inte-grated management strategy is needed, in particular, one thatconsiders the link between Wildlife Trees and CWD. Achieve-ment of this goal will require research on the mechanisms ofCWD recruitment; development of strategies for optimizingthe distribution of reserves; and a commitment to ensuringthat the prescribed number and sizes of trees will fall through-out the rotation, either naturally (i.e., natural mortality andwindthrow) or manually (Carey et al. 1996). The developmentof quantitative CWD management objectives over the nearfuture will facilitate this process.

Currently in British Columbia, the achievement of CWD man-agement objectives is tied to designated reserves of trees (e.g.,Wildlife Tree Patches). The net down to the Allowable Annual

Cut (AAC) for trees providing CWD recruitment is accountedfor in the AAC net down for the reserve. Leave trees otherthan those in reserves (e.g., seed trees, low-value trees, trees inSilviculture Retention Patches) that are a potential source ofCWD recruitment9 are not retained because there is an associ-ated reduction to the AAC determination. �Standing leave trees(specified in the Silviculture Prescription and Cutting Permit)are not charged to the Licensee�s AAC or billed through theCut Control. They are accounted for at the time of the ChiefForester�s AAC determination. To the extent that trees are leftstanding on the block to address CWD recruitment, a deduc-tion is made in the Timber Supply Analysis and is reflected in

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6



the determination. Therefore, the AAC may be slightly lowerthan it would be if no trees were being retained on the blocks.�10

The Timber Supply Analysis incorporates the leave tree vol-umes into the AAC determination. In the case of seed trees,for example, it is assumed that the seed trees will be removedduring the rotation. If these trees are felled to meet CWDobjectives, the volume associated with the seed trees will beunavailable for removal, and constitute a reduction in the AAC.The assessment does not, however, take into account the tim-ber volume associated with the �fill-in� trees, which will beavailable for harvest at the end of the rotation.11

2.2 Options for Maximizing CWD in the Setting,Post-Harvest

Based on the above observations, there are three main toolsthat could be used on the Coast of British Columbia for increas-ing CWD retention in the dispersed setting at the time of harvest:

1. Reduce roadside accumulations12 by bucking out Y Grade,Z Grade, and leaving this wood in the setting.

2. Protect existing dead down wood below the utilizationstandards.

3. Provide leave trees in reserves as a source of CWD dur-ing the rotation.

Coastal, old-growth, stands provide the best opportunity to leavelow-value wood in the setting through modified bucking andyarding practices (e.g., bucking out low-value wood, markingwhich pieces to leave on site, identifying no-yarding areas) be-

cause of the high incidence of defect in the timber. Further,because CWD volumes are high and piece sizes are large inold-growth compared to mid-seral stages of development (Spiesand Franklin 1988; Wells et al. 1998) there is more opportunityto maintain large pieces of CWD. Implementing these prac-tices will be more challenging in cable-harvesting operationsthan in helicopter operations. Leave trees in reserves are alsopotential sources of CWD in old-growth stands, although fur-ther study is required to evaluate the effectiveness of reservesas CWD recruitment centers with regard to the distribution,frequency, and size of CWD inputs over multiple rotations,and to evaluate incremental costs.

In contrast to the old-growth stands, mature, second-growthCoastal stands have limited defective wood in the timber (Ruthand Harris 1975; Nagle 1980), and carry-over of CWD vol-ume from the previous stand is at a natural low (Spies andFranklin 1988; Wells et al. 1998). Stem diameters in second-growth stands are generally smaller than those of old-growth

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:)selipnidnaedisdaorta(snoitalumuccAm001 3 )sgolretteb-dna-edarG-X(

htworgdnoceS :desrepsiDm51 3 )sgolretteb-dna-edarG-X(ah/

:)selipnidnaedisdaorta(snoitalumuccAm05 3 )sgolretteb-dna-edarG-X(

a :seicilopnoitaziliturebmittuobasliatederomrofsecruosgniwollofehteeS,sreganaMtcirtsiDdnalanoigeRllaot)noisiviDsnoitarepO,retsiniMytupeDtnatsissA(immuKannaJmorf,mudnaromemlanretniFOMCB-

.9991yraunaJ02;yciloPnoitazilitUrebmiT:ersreganaMlanoigeRllAot)hcnarBgnireenignEdnaseruneTecruoseR,rotceriDtnatsissA(kulirwoGmiJmorf,mudnaromemlanretniFOMCB-

.9991yraunaJ22;yciloPnoitazilitUrebmiT:er,sreganaMtcirtsiDllAdnab .gnitsevrah)ssap-tsrif(yramirpotseilppA

Table 2. Timber utilization policies: Avoidable Waste Benchmark volumes. a

10 M. Mana, RPF, Compliance and Enforcement Office, BC Ministry of Forests,Vancouver Forest Region, Nanaimo, BC; personal communication, May 2001.11 See Footnote 10.12 Current forest practices involve yarding of some non-merchantable logs toroadside for a variety of reasons: 1) because merchantability is not visibleuntil the log is yarded to roadside; 2) to ensure the operation is not penalizedfor leaving merchantable logs on the setting; or 3) because worker training isinadequate. In addition, some low-value/non-merchantable material is loaded,trucked, sorted, and disposed of at the dryland sortyard. It is estimated thatapproximately 0.4% of volume put through dryland sortyards is roundwood thatrequires disposal (Forrester 1996, cited in Phillips 2001).

7



stands, thereby reducing opportunities to leave larger-sizedpieces of wood.13 In Coastal, mature, second-growth stands,leave trees and protection of existing large CWD, when present(i.e., through modified yarding practices such as designated trailsaround legacy pieces), represent the main opportunities tomanage for CWD under the current timber utilization policy(BCMOF 1997). However, as mentioned above, the effec-tiveness of the former option requires further investigation.

3 STUDY OVERVIEW:MODIFIED BUCKING AND YARDING PRACTICES

3.1 Overview

In Coastal British Columbia, strategies are being sought tomaximize the retention of CWD on timber-harvesting sites,because CWD is recognised as a critical component of for-ested ecosystems. In old-growth stands, two strategies have beensuccessfully used in helicopter operations to reduce haulingcosts and dryland sort accumulations, with the added benefitof maximizing the retention of low-value/non-merchantablewood in the dispersed harvesting setting. These two strategiesinvolve the following modified harvesting practices:

� Bucking on site to create higher value logs. In this ap-proach, low-value/non-merchantable wood (i.e., Z and YGrades) is bucked and left in the setting.

� Marking low-value/non-merchantable wood (i.e., Z and YGrades ) for the purpose of leaving on site (mark to leave,MTL). A scaler marks low-value/non-merchantable woodwith paint after falling and bucking, but prior to yarding.

In 1999, Weyerhaeuser�s BC Coastal Group and the BC Min-istry of Forests embarked on a co-operative project to exam-ine the feasibility of applying the above modified practices,currently used in Weyerhaeuser�s helicopter operations, to otherharvesting systems. The perceived benefits included: i) reducedcosts associated with yarding, loading, trucking, and disposingof low-value/non-merchantable, and ii) increased amount anddistribution of coarse woody material retained in the cutblock.

Prior to embarking on the multi-year project proposed in theworking plan14, a decision was made to complete a pilot studyin order to evaluate the sampling protocol and the operationalfeasibility of applying these modified practices to other har-vesting systems. Opportunities to increase CWD retention byprotecting existing dead wood on the ground, or by providingfor leave trees, were not incorporated into the pilot.

In 1999 an old-growth stand with a high proportion of defec-tive wood was chosen as the site for the pilot study. An old-

growth rather than a second-growth site was chosen for studybecause the benefits of applying the modified bucking andyarding practices in younger stands were expected to be lim-ited, due to the low volumes of defective wood in these stands.

The site selected for the pilot study was divided into two studyblocks, one of which was harvested by conventional meansand the other by a mark-to-leave method. Evaluation of thetwo methods was based on a comparison of costs and on anassessment of the pre- and post-harvest dead wood.

3.2 Study Objectives:Economic and Dead-Wood Components

3.2.1 Broad Objectives

The overall objectives of the pilot and main (multi-year) studyhave two basic components:

Economic component

� Monitor and compare the logistics of conventional yard-ing with yarding where low-value/non-merchantable wood(i.e., Y Grade and Z Grade) is marked.

� Estimate the costs of loading, transporting, and sorting low-value/non-merchantable logs (i.e., Y Grade and Z Grade).

� Determine whether the marking of low-value/non-mer-chantable wood (i.e., Y Grade and Z Grade) after fallingput prior to yarding is an effective and economically fea-sible method to increase CWD left in post-harvest settings.

Dead-wood (CWD) component

� Provide baseline data about the structure of old-growth forests.

� Quantify pre- and post-harvest differences in CWD at-tributes between conventional and modified bucking andyarding practices.

� Compare potential pre-harvest sources of CWD and as-sociated attributes to post-harvest CWD attributes.

� Quantify CWD volume and piece density removed throughpost-harvest salvage.

3.2.2 Objectives of the Pilot Study:Assess Pre-Harvest Dead WoodThe specific objectives of the pre-harvest survey of dead woodare to:

� Test for between-block differences in total site, live tree,dead tree, CWD, and stump volumes (H

0: no significant dif-

ference between Conventional and Mark-to-Leave Blocks);

� Test for between-block differences in merchantable andnon-merchantable wood volumes (H

0: no significant differ-

ence between Conventional and Mark-to-Leave Blocks); and

� Test for between-block differences in the density and vol-ume of �potential� large low-value/non-merchantable logsin the standing timber (H

0: no significant difference between

Conventional and Mark-to-Leave Blocks).

13 In the case of stands that were “high-graded” during previous harvestingoperations, residual CWD levels may be higher than expected.14 G. Davis, E. Phillips, and B. Cawley. 2000. Maintaining Coarse Woody Debrisin Post-Harvest Settings: Economic and Ecological Implications of MarkingNon-Merchantable Logs after Bucking and Before Yarding, Project Plan.Research Section, Vancouver Forest Region, BC Ministry of Forests.VFR-CWD-00-01, internal document.

8



4 PROJECT DESIGN AND IMPLEMENTATION

4.1 Site Selection

Selection of the study site was governed to a great extent byharvesting schedules; the intent was to have harvesting com-pleted by the end of the BCMOF�s 2000/2001 fiscal year (i.e.,March 31). General site and operational factors considered inthe site selection include:

� Old-growth stand.

� �Uniformity� of timber types: <3 dominant types.

� �Uniformity� of dominant moisture/nutrient regime: <3dominant regimes.

� Site size between 20 and 30 ha, to permit division into twostudy blocks.

� Travel distance <1.0 h from main junction.

� Presence of decay/waste/breakage indicators in stand.

� Ability to split block into two fairly homogeneous study blocks.

Old-growth was targeted because these forests/ecosystems havethe greatest volume of low-value wood due to advanced standage and a corresponding high level of defect and decay.

4.2 Site Description 15

The harvesting site is located in Tree Farm Licence 39 ofWeyerhaeuser�s North Island Timberlands, Kelsey Bay Opera-tions; Weyerhaeuser identifies the site as Block Number OP.3057 UA106D3F. It is located on north Vancouver Island, inthe Adam River drainage: 10 km north of the Sayward junctionon Highway 19, 600 m left past the Keta Lake rest area and 8.5km northwest up the Adams River branch road UA106D3.

The harvesting site is located in the Montane variant of theVery Wet Maritime subzone of the Coastal Western Hemlockbiogeoclimatic zone (CWHvm2) and is classified as NaturalDisturbance Type 1 (NDT1 = disturbance interval >250 years)(BCMOF 1995.) It is in a mid to upper slope position at anelevation of 740�940 m. The block is located on well drainedgentle to steep slopes (25�60%); faults are associated with thelatter. The slopes are east to north facing.

The soils are well drained, shallow to moderate, medium tex-tured (silt loam mineral horizons) over compacted tills or bed-rock outcrops. Coarse fragment contents vary from 40 to 60%.The soils are classified as Humo-Ferric Podzols. The overlyinghumus form is a MOR ranging from 15 to 30 cm deep.

The site is uniformly zonal (01) with small localized areas ofmoister, richer sites in the vicinity of seepage/stream loca-tions. The three seepage areas identified are 07 and 10 siteseries. The moisture/nutrient regime for the majority of theblock ranges from 3/C to 4/C.

The opening includes an in-stand reserve (0.5 ha) which is en-tirely within the opening boundaries and incorporates an areaof steep rock outcrops and a long, narrow, natural, rock cre-vasse feature. A large Wildlife Tree Patch is adjacent to the site.

4.3 Stand Description

The forest is an uneven-aged, old-growth stand (150 to ≥450years). It is comprised of western hemlock (Hw) (Tsugaheterophylla) and amabilis fir (Ba) (Abies amabilis), with a minorcomponent of cypress (yellow-cedar) (Yc) (Chamaecyparisnootkatensis) (Figure 1). As per the operational cruise, total netmerchantable volume is estimated at 852 m3/ha with a speciescomposition of Ba

49Hw

48Yc

3 (Table 3). The forest cover is semi-

open, and multi-storied, with 25�30-m-tall Hw and Ba over inter-mediate BaHw layers including advance regeneration that is 2�10m tall. Crown closure varies from 50 to 80%. The standing tim-ber has a high occurrence of conks, dead or broken tops, andscars (Figures 2, 3, and 4). Snag density is fairly low. Thedead wood on the ground ranges from Moderately Decayed toWell Decayed (Figure 5). It is assumed that this stand is rep-resentative of old-seral forests in the Montane variant of theVery Wet Maritime subzone of the Coastal Western Hemlockbiogeoclimatic zone (CWHvm2) being harvested by the KelseyBay Division of Weyerhaeuser�s Coastal BC Group.

Four broad timber types were identified (Table 4). Their ap-proximate locations are provided in Figure 6.

4.4 Layout

The harvesting site is 24.6 ha; this excludes an 8.6-ha WildlifeTree Patch that lies outside the block boundaries, but includesa 0.5-ha in-stand reserve. Based on operational constraints, the

15 The information presented here about the site has been garnered from thefollowing two documents: –R.A. Harder and L.W. Apedaile, Silviculture Prescription for BLK 3057,November 27, 1998; Weyerhaeuser, BC Coastal Group, Nanaimo, BC; internaldocument. – M. Fidgeon, Coarse Woody Debris (CWD) Pilot Study – Field Assessment ofPotential Study Sites, November 21, 2000; Vancouver Forest Region, BCMinistry of Forests, Nanaimo, BC; internal document. Figure 1. Site overview. (Photo: E. Phillips, FERIC)

9



Table 3. Stand statistics: Operational Cruise Summary. a

scitsiretcarahc/sretemaraP sserpyC kcolmehnretseW rifsilibamA latoT

stimilnoitazilitU

)mc(hbd.niM 5.71 5.71 5.71 5.71

)mc(thgiehpmutS 0.03 0.03 0.03 0.03

)mc(.maidpoT 0.51 0.51 0.51 0.51

)m(htgnelgoL .a.n .a.n .a.n .a.n

edargyb,.lovteNm( 3 ).lov.hcremten%/ah/

3.7 %2 3.7 %1

DedarG 8.3 %41 1.4 %1 1.6 1% 41 %2

FedarG 0.21 34 % 2.95 41 % 5.531 33 % 7.602 %42

HedarG 5.2 9% 3.19 22 % 3.55 41 % 1.941 %71

IedarG 6.62 6% 1.94 21 % 7.57 %9

JedarG 6.7 %72 8.941 63 % 0.301 52 % 6.062 %13

UedarG 4.1 5% 5.22 5% 3.11 3% 2.53 %4

XedarG 9. 3% 4.36 51 % 3.93 01 % 5.301 %21

YedarG 1.82 101 % 9.614 99 % 1.704 001 % 1.258 %001

m(tenlatoT 3 )ah/ 3.3 9.84 8.74 001

)%(nwodwolbtenlatotfo%seicepS

m(ZedarG,)etsaw(lluC 3 )ah/ 0.0 6.2 8.0 4.3

m(egakaerB 3 )ah/ 1.2 4.92 0.72 5.85

m(yaceD 3) 9.1 8.98 8.44 5.631

m(noitcudedlatoT 3 )ah/ 0.4 8.121 6.27 4.891

.lov.hcremssorglatoTm()C+B+AssalCeerT( 3 )ah/

1.23 7.835 7.974 5.0501

.lov.hcremssorgfo%lluC)%()C+B+AssalCeerT(

5.21 6.22 1.51 9.81

m(edargyb,krabedisni.maidpot.gva,SPA 3 )mc/

DedarG 56.5 49 56.5 49

FedarG 69.3 86 19.2 26 98.2 47 31.3 96

HedarG 70.3 25 77.2 85 00.2 15 22.2 35

IedarG 10.2 94 70.3 46 14.2 06 77.2 26

JedarG 75.0 42 65.0 62 65.0 52

UedarG 20.1 52 61.1 03 16.0 22 58.0 62

XedarG 09.4 631 19.0 73 53.1 94 60.1 14

YedarG 04.1 901 58.0 83 36.0 23 57.0 53

krabedisni.maidpot,SPAseicepS 59.1 34 72.1 73 69.0 23 11.1 43

egnarhbdyb,ah/smetS

).on(mc4.22-5.71 6.81 4.42 0.34 %2.61

).on(mc4.23-5.22 0.42 0.42 %0.9

).on(mc4.74-5.23 8.62 5.03 3.75 %5.12

).on(mc4.27-5.74 1.92 7.24 8.17 %0.72

).on(mc4.79-5.27 9.3 5.12 2.91 6.44 %8.61

).on(mc591-5.79 3.0 8.81 3.6 4.52 %6.9

).on(mc+1.591

latoT 2.4 8.411 1.741 1.662 %001

ssalceertyb,ah/smetS

).on(gnidnatsevil,AssalC 2.4 6.211 3.541 1.262 %2.89

).on(gnidnatsdaed,BssalC 2.2 8.1 9.3 %5.1

).on(nwoddaed,CssalC

).on(sselesu,denibmocE&DsessalC 8.5 9.8 7.41

)m(thgieh.hcrem.gvA 0.92 8.22 9.02 8.12

)m(thgiehlatot.gvA 9.33 3.92 2.72 2.82

sgnilipdnaseloPa .)4168.oNtcejorPesiurC,selpmas62(atadesiurcresueahreyeW:ecruoS

10



Figure 2. Conks. (Photo: C. Redlin, Azmeth Forest Consultants)

Figure 3. Frost crack. (Photo: C. Redlin, Azmeth ForestConsultants)

harvesting site was split into two study blocks with the access roadserving as the most efficient dividing line. The conventional andmark-to-leave practices were randomly assigned to the studyblocks. Two yarding methods were used in both blocks: excava-tor (hoe) forwarding to roadside and grapple yarding (Phillips 2001).In this report the two study blocks are referred to as the Mark-to-Leave Block and the Conventional Block.

Table 5 summarizes the area associated with each study block,treatment, and harvesting method. Figure 6 shows block layout.

4.5 Bucking and Yarding Practices

The following provides a brief overview of the operationalaspects of the two practices evaluated in the study. Furtherdetail is available in a progress report produced by the ForestEngineering Research Institute of Canada (FERIC) (Phillips2000) and in Appendix B. Table 6 provides an approximateschedule of activities.

As a general rule, each harvesting stage was completed in theConventional Block prior to the Mark-to-Leave Block. Thepresence of fog and snow started to affect the yarding by midOctober. This was early on in the yarding phase of the Mark-to-Leave Block. November 24, 2000 was the final day for

Figure 4. Windfall. (Photo: C. Redlin, Azmeth Forest Consultants)

11



operations. At shut down, less than 20% of the volume on theMark-to-Leave Block remained to be yarded. Over 50% ofthe mark-to-leave wood was cold decked for hauling in thespring. During operations, the crew worked around weather-related shutdowns (e.g., a record rainfall on October 20, fog,snow); scheduled operational shutdowns (October); schedulingof equipment; staff holidays; and staff changes.

4.5.1 Falling, Bucking, and Marking

Separate falling crews were used in each block. Hand falling wasused on both blocks (Phillips 2001). The modified bucking/yard-ing was carried out by a crew that had prior experience with�best value� bucking in Weyerhaeuser�s helicopter operations.

Conventional Block. Trees were felled and bucked toWeyerhaeuser�s preferred log lengths, which are based on grades(Appendix B-2 of Appendix B). Four fallers were involved inthe conventional harvesting.

Figure 5. Well-Decayed CWD. (Photo C. Redlin, AzmethForest Consultants)

Table 4. Broad timber types found at the study site.

Table 5. Areas corresponding to site, Wildlife Tree Patch,and yarding method, by study block.

rebmiTepyt seicepS aeralatoT

)ah(1 wHaB

)wHaBretemaid-egral(7.9

2 wHaBdnaaBretemaid-egral(

)wHretemaid-llams

6.2

3 wHaBdnaaBretemaid-llams(

)wHretemaid-llams

59.4

4 wHaBdnaaBretemaid-llams(

)wHretemaid-egral

50.6

sretemaraP aerA

kcolbydutS-ot-kraM

evaeL-nevnoC

lanoitsezishctaPeerTefildliWdnaetiS

)ah(etisgnitsevrahfoaerassorG 0.33

hctaPeerTefildliWfoaerAehtfoseiradnuobehtedistuo

etisgnitsevrah )ah(

6.8

gnidulcni,aeragnitsevrahssorGnihtiwhctaPeerTefildliW)ah(seiradnuobgnitsevrah

6.42

nihtiwhctaPeerTefildliWfoaerA)ah(seiradnuobgnitsevrah

5.0

)ah(ycnapuccodaoR 8.0

)ah(tenlatoT 3.32

dohtemgnidraY

)ah(aeraedisdaoR 5.1 7.2

)ah(aeradekcuhc-eoH 2.1 6.0

)ah(aeradedrayelpparG 0.7 3.01

)ah(desrepsidsadetangisedaeralatoT 3.8 9.01

)ah(desrepsid+edisdaorlatoT 7.9 6.31

)%(tenlatoT 24 85

stolpfonoitubirtsiD

).on(desrepsidsadetangisedstolplatoT 11 21

)%(aeradesrepsidlatoT 31 11

ytivitcAkcolbydutsdna etaddne/tratS

gnikcub/gnillaFlanoitnevnoC trats0002yluJ91

gnillaFevaeL-ot-kraM 0002rebmetpeS81otyluJ42

gnidrawrofeoHlanoitnevnoC trats0002rebmetpeS70evaeL-ot-kraM etelpmoc0002rebotcO20

gnidrayelbaClanoitnevnoC 0002rebmevoN01otrebmetpeS21evaeL-ot-kraM 0002rebmevoN42otrebmevoN31

)1002enuJ81otyaM20(

nwodtuhsdeludehcS 0002rebotcO61otrebotcO60

wonstsriF 0002rebmevoN11

Table 6. General schedule of activities.

12



Figure 6. Site map (scale 1:5000). (Map prepared by C. Redlin, Azmeth Forest Consultants, 00/7/18)

13



Mark-to-Leave Block. After falling, licensed metric log scal-ers trained a second four-person falling crew to buck to re-cover maximum log value and to decrease the amount of cullattached to market logs, without increasing the volumes ofbillable residue and waste.

The second falling crew was given detailed bucking instruc-tions for the Mark-to-Leave Block, with specific reference to:retaining long butts where there was a severe defect or rot;bucking out log sections with conks; removing shattered por-tions of logs; bucking out portions of the tree containing Y orZ Grade wood; and maximizing the value of logs bucked fromeach tree by ensuring diameter, length, and quality of log wereoptimized. Further detail is provided in Appendix B.

Following bucking, but prior to yarding, licensed metric logscalers (who are also residue and waste surveyors) marked withpaint any log that had been bucked off to minimize cull i.e.,low-value wood or because it was below minimum recoveryspecifications. Several blue spots, each approximately 20 cm2,were painted on the log on the side that would be visible to theyarder. Mid way through yarding, pieces were remarked with amore-visible pink paint because the snow had obscured or fadedthe original marks.

4.5.2 Yarding PracticesThere was considerable overlap in yarding operators and equip-ment used in both blocks. The majority of the harvesting sitewas grapple yarded by a three-drum Madill 044 swing-yarderequipped with a single walking guy line. Gentle terrain was ex-cavator forwarded (hoe-chucked) with a Kobelco SK400LLhydraulic log loader. This machine was also used for wide right-of-way yarding and for loading trucks. Wood was yarded bothuphill and downhill in the Conventional Block and downhill inthe Mark-to-Leave Block. Logs were transported with tridem/tridem-tractor/pole-trailer highway trucks (7-axle configuration)to a central dryland log-sorting yard via off-highway roads(Phillips 2001).

Conventional BlockExcavator Forwarding. The excavator-operator com-mented that, as a general rule, he was able to identify low-value/non-merchantable wood, because he was able to moveeach piece and bring it close to the cab. For various reasonslow-value/non-merchantable pieces were often displacedfrom their original locations. In some cases, wood was for-warded with one or more swings before determining that itwas in fact low-value/non-merchantable. In other cases itwas necessary to move logs to provide access or machinecorridors, or to improve visibility for determining merchant-ability. Small and/or broken pieces were piled by the exca-vator to improve its mobility and to improve access to wood.

Grapple (Cable) Yarding. The yarding engineer deter-mined merchantability, with the assistance of spotting bythe hooktender when the logs were not clearly visible. Whenthe yarding was complete on one yarding road, thehooktender walked the yarding road to ensure all merchant-

able wood had been yarded before the yarder or backsparwere moved to access a new, unyarded area. If the yardingengineer questioned the merchantability of a log, then thehooktender (spotter) was asked to do a close-up visual in-spection of the log. The yarding engineer dropped any logthat started to fall apart during grappling or hauling, andwent back for another.16 The yarding engineer and thehooktender communicated by radio.

Mark-to-Leave BlockThe yarding and loading operators were informed that, ifpossible, they were not to yard or load any marked logs.They were also asked to watch for, and leave on site, anyobvious cull logs that were not painted. A quality-controlsupervisor, who visited the yarding and loading crews ap-proximately every two weeks, monitored the operations.

Excavator Forwarding. The excavator-operator was ableto see the blue paint with minimal trouble. Nevertheless,sometimes pieces of wood had to be moved, sometimesmore than once, in order to check for paint, to ensure nomerchantable wood was underneath the piece, and to pro-vide access for the hoe. As a result, pieces were often notleft in their original locations.

Grapple (Cable) Yarding. In the Mark-to-Leave Block,grapple yarding occurred in much the same fashion as inthe Conventional Block, with the exception that piecesmarked with blue paint were to remain in the setting. Thehooktender and the chaser (when available) also assistedwith identifying painted logs where visibility was poor (e.g.,due to snow, gullies, knobs).

The yarding engineer commented that, where the terrainwas steep, marked pieces were often inadvertently movedfrom their original locations, for several reasons. Typically apiece was picked up by the grapple for the operator to view.If paint was obviously visible the piece was dropped; how-ever, in sloping terrain the piece would often roll into anunyardable area, e.g., a gully or out of reach of the yarder.If the paint was not obviously visible the piece was yardedtoward the road until the paint became visible, at whichtime the piece was dropped. In these two scenarios, accu-mulations can occur in specific locations along the slope. Inother instances, the grapple may have picked up two pieces,one with and one without paint. Both were yarded to theroadside, one was hauled, and the other was left at the road-side. Fog and snow compounded these problems.

5 METHODS

5.1 Definitions

Trees: Live and dead trees that are ≥3 m in height with a dbh≥10 cm; fallen trees must have roots attached and dbh within the

16 Eric Phillips, Senior Researcher, Silviculture Group, Western Division, ForestEngineering Research Institute of Canada (FERIC), Vancouver, BC; personalcommunication, June 2001.

14



cruise plot boundary (see Cruise Measurements section below).

Stumps: Natural or cut tree, with roots attached and rooted,≥0.3�2.99 m in height with a top diameter ≥10 cm.

CWD: Natural or cut, dead, down wood with a small-end di-ameter ≥10 cm; overlap with windfalls was recorded.

5.2 Cruise Measurements

The cruise procedures follow the Vegetation Resources InventoryGround Sampling Procedures Manual (BCMOF 2000c), with theexception that nested fixed-area plots rather than variable ra-dius (prism) plots were used and Z Grade logs were distin-guished from Y Grade logs. A total of 23 sample plots werelocated systematically throughout the cutblock: 12 in theConventional Block and 11 in the Mark-to-Leave Block. These23 plots were located in the area outlined on the harvestingmap as the dispersed stratum. Each cruise plot consisted oftwo nested sub-plots with radii equal to 11.28 m and 17.84 m(Table 7). The 11.28-m radius subplot (400 m2) includedmeasures on all standing and fallen trees ≥10 cm dbh, whilethe 17.84-m subplot (1000 m2) includes measures on all trees≥50 cm dbh. Plot centers were staked, pinned, and referencedto at least two trees within the plot.

For all trees, standing or fallen (1.3 m in plot with roots), thefollowing attributes were recorded: species, dbh, actual height,live/dead, standing/fallen, crown class, height to live crown,net factor call grading for all logs, pathological indicators, WildlifeTree appearance codes, and tree class codes. Table 8 providesgeneral definitions for tree classes used in the study. Furtherinformation on measurement attributes is available in the Work-ing Plan17. Trees along the boundary of any plot18 were in-cluded in the tally if 50% or more of the tree at dbh wasinside the plot boundary.

5.3 Measurements of Coarse Woody Debrisand Stumps

Measurement of CWD and stumps followed field proceduresoutlined in the Logging Residue and Waste Procedures Manual(BCMOF 2000a) with two major modifications:

i) nested, fixed-area plots were used, andii) low-value/non-merchantable wood was measured.

Three, rather than two, fixed-area nested sub-plots were used

to measure down wood at the same locations as the pre-har-vest cruise plots (see Section 4.2 of this report) The three sub-plot radii were 3.99 m (50 m2), 11.28 m (400 m2)19, and 17.84m (1000 m2). The two largest diameter sub-plots coincide withthe nested cruise plots. The piece-selection criteria for eachplot follows:

� 3.99-m plot: pieces and/or stumps in the plot with a vol-ume <0.024 m3 (entire piece) and a small-end inside barkdiameter ≥10 cm.

� 11.28-m plot: pieces and/or stumps in the plot with a volume>0.024 m3 and a small-end inside bark diameter ≥10.

� 17.84-m plot: pieces and/or stumps in the plot with a volume>0.024 m3 and a small-end inside bark diameter ≥30 cm.

Attributes both inside and outside each plot (e.g., length, small-end and large-end diameters) were recorded. For all plots, theminimum small-end inside-bark diameter was 10 cm, and lengthwas recorded to this minimum. The purpose of the nestedplots and minimum size criteria were to increase the samplingrigour for large pieces. A CWD piece 3 m in length with aminimum 10-cm small-end diameter fits the Manual�s defini-tion of a residue and waste log (for second growth).20

Plot boundaries were painted on the ground prior to field sam-pling. Field measurements included: species; borderline (i.e.,whether or not the piece intersects the plot boundary); kind;waste class; small-end and large-end diameters inside and out-side the plot; large-end and small-end codes; piece length insideand outside the plot; grades and deductions for the sections oflog within and outside the plot; codes for live, dead, or original;and comments (e.g., number of segments, buried, recon-structed). Additional measurements included ecological codes(decay, bark, hardness, and orientation). Appendix V of thisproject�s working plan21 provides more detail.

General sampling rules included:

� Record width and height (inside bark) for all pieces with non-round diameters (all pieces with a decay code of 3, 4, or 5).� Measure broken pieces <0.5 m apart as if they were one piece(if they are positioned in the same direction and it is clear theyoriginate from the same log) and record number of segments.� Reconstruct pieces that are split horizontally but still have aportion touching each other.� Assess grade and % sound separately for the log portionsinside and outside the plot, and assess ecological decay codes,% bark, and hardness for the entire piece.

epyttolpdnamutartS

stolpdetsenfoiidaR

tsevrah-erP)m(

kcolbtuC a

esiurC 48.71/82.11

DWC/pmutS 48.71/82.11/99.3a .tsevrah-tsopdesrepsidsaotderrefeR

Table 7. Summary of pre-harvest strata.

17 See Footnote 14.18 A tree was included in the timber cruise if it had attached roots and its dbh(1.3 m from high side) was within the plot boundary.19 An 11.28-m radius plot is the standard residue and waste plot size. The largerplot (17.84 m) will improve parameter estimates for larger sized pieces. In futuretwo plot sizes rather than three will be used, to make data collection easier.20 A CWD piece with large-end and small-end diameters of 10 cm and 3 m longis equal to 0.024 m3 (assumes minimum taper).21 See Footnote 14.

15



� Record the outside and inside dimensions of hollow logs (i.e.,small-end and large-end diameters).� Record two types of windfalls (i.e., logs with roots attached)�those with the 0.3-m bole inside the plot and those with the 0.3-m bole outside the plot.

5.4 Site Index and Tree Age

Prior to the commencement of harvesting, 5 of the 23 cruiseplots were randomly selected for site-index (SI) measurements. A0.01-m2 plot was established in the center of each cruise plot and

one site index (SI) tree of the leading species and one of thesecondary species were selected from each plot (see Section4.8 of Vegetation Resource Inventory Manual (BCMOF 2000c).

On three of the five plots, two dominant or co-dominant treesof the leading and secondary species, in addition to two inter-mediate trees of the leading species, were randomly selected fordetermining tree age. Trees were selected irrespective of defects.

Both SI and random trees were triangulated to the plot center.Stem maps were drawn to permit post-harvest collection of disks.

sessalCeerTs'resueahreyeW )b0002FOMCB(sessalCeerTgnidnopserroCs'FOMCB

metSeviL-A.seertgnidnats,eviL

srotacidnilacigolohtaplanretxethgieehtfoenonhtiwseertgniviL-1.)laudiseR(

:yacedfosrotacidnilacigolohtapthgiefoeromroenohtiwseertgniviL-2eoteltsim,kcarctsorf,koorcdecnuonorpro/dnakrof,sracs,sknocdnilb,sknoc

.)tcepsuS(potnekorbrodaed,sehcnarbnettor,)noitcefnikcurt(

seicepsllarofredlorosraey121(eertgnivilerutamasadenifedsinaretevA-5ni)sraey08>aL&KZIFninepsadnadoownottocrosraey04>suoudicedtpecxe

.)nareteV()sraey121<(erutammisadeifissalcneebsahhcihwdnatsniama

htiwdenibmocerayehT.sbmilevilowtroenoylnoevahtahtseertgniviL-6.sgans%fonoitalipmocehtrof4ssalCeerT

anihtiw)sraey121<(eerterutamminasadenifedsimetserutamminA-8.dnatserutam

gnidnatSlaitnetoPdaeD-Bstifo%05tsaeltahtiwseertgnidnats,daeD

.tnetnocdoow-dnuosniemulovssorglanigiro

fo%05tsaeltaniatnocotdetamitsesihcihwrebmitnwodrognidnatsdaeD-3.)laitnetoPdaeD(tnetnocdoow-dnuosniemulovssorglanigirosti

otderrefersidna3dna5sessalCeerTfonoitinifedehtsenibmocssalcsihT-75sessalCeerTdenibmocrofselbatrotcafssolehT.laitnetoPdaeDnare-teVasa

.noitalipmocehtnideilppaera3dna

derrefersidna3dna8sessalCeerTfonoitinifedehtsenibmocsissalcsihT-9srotcafssol3dna8ssalCeerTdenibmocehT.laitnetoPdaeDerutam-mIsaot

.noitalipmocehtnideilppaera

nellaFlaitnetoPdaeD-C%05tsaeltahtiwseertnellaf,daeD

doow-dnuosniemulovssorglanigirostifo.tnetnoc

.evobasA-3

.evobasA-6

.evobasA-7

.evobasA-9

gnidnatSsselesUdaeD-Driehtfo%05<evahtahtseertgnidnatsdaeD

rotnetnocdoow-mrifniemulovssorglanigiroevobaehtfoairetircehtteemotliafesiwrehto

.noitinifedgnidnatSlaitnetoPdaeD

-mrifniemulovssorglanigiroriehtfo%05<evahtahtseertgnidnatsdaeD-4daeD(3ssalCeerTfoairetircehtteemotliafesiwrehtorotnetnocdoow

.)sselesU

nellaFsselesUdaeD-Eriehtfo%05<evahtahtseertnellafdaeD

rotnetnocdoow-mrifniemulovssorglanigiroevobaehtfoairetircehtteemotliafesiwrehto

.noitinifednellaFlaitnetoPdaeD

a .)b0002FOMCB().snialpnretsaEhtroN=L.acenimO,reissaC,noigeRlartneChtroN=K(.enoZyrotnevnIyrtseroF=L&KZIF

Table 8. Definitions of tree classes used by Weyerhaeuser and the BCMOF.

16



6 ANALYSES

The overall objective of the pilot study analysis is to estimateand compare relevant properties of the Conventional and Mark-to-Leave Blocks, before and after harvesting. This informa-tion will be used to assess the merits and potential difficultiesof conducting the multi-year study in which the two harvestingmethods will be replicated at other sites. The pre-harvest analy-ses include only the 23 plots located in the area identified asthe dispersed stratum, i.e., the analyses exclude roadside.

6.1 Pre-Harvest Analyses

The specific objectives of analysing the pre-harvest data are to:

1. Describe the pre-harvest conditions in the Conventionaland Mark-to-Leave Blocks, by estimating (for each block)the parameters listed in Tables 9 and 10.

2. Test whether the total volumes and total dead-wood vol-umes and component volumes (e.g., Z and Y Grades) dif-fered significantly between the two blocks before harvest-

Table 9. Compilation piece definitions. a

seertnellafdnagnidnatsdaeddnaeviL-1 (≥ )thgiehnim3

:seertesiurC nellafdniw,.e.i(seertnellafdnagnidnats b)

hbdahtiw ≥ .mc5.71

:seerTdezisrednU hbdahtiwseertnellafdnagnidnats≥ .mc5.71<dnamc01

)i ytisneD .)dezisrednudnaesiurc,ah/seertrebmun(

)ii ah/emulovssorG

seertesiurC -potkrabedisnimc-51aotsgoldezis-elbatnahcrem)1

;retemaid)poteertotretemaidkrabedisnimc-51morfelob(pot)2

.denibmoc)thgiehnim3.0<(pmutsdna

seertdezisrednU -;mc5.71<hbdesuacebsgoldezis-elbatnahcremon)1

;thgiehpmutsm-3.0aoteerteritne,spot)2.thgiehnim3.0<,spmuts)3

)iii ah/emulovteN

edisnimc-51aotsgoldezis-elbatnahcrem-seertesiurC.retemaidpotkrab

.emulovtenelbatnahcremon-seertdezisrednU

spmutS-2 retemaidpotrohbdahtiwdoowdaeddetoor(≥ sihcihw,mc01 ≥ )thgiehnim0.3<dnam3.0

)i ytisneD .)ah/spmutsforebmun(

)ii ah/emulovssorG

)alumrofnailamS(diolobarapfoah/emulovssorG ≥ nim3.0rodetaluclactonsithgiehnim3.0<emulovpmuts(thgieh

.)dekcart

DWC-3 )seceipnwoddaedlla(

:sllafdniW tolpaera-dexifnihtiwsllafdniwfosnoitropmuminimadnaretemaidBIdne-egralehtneewteb

retemaidBIdne-llams ≥ .mc01

)sllafdniw-non(DWCrehtO daedrehtollafosnoitrop:tolpaera-dexifehtnihtiwdoowgnitroppus-nondnanwod

muminimdnaretemaidkrabedisnidne-egralneewtebretemaidkrabedisnidne-llams ≥ .mc01

)i ytisneD "rehto"dnallafdniwfomuS.)ah/seceipforebmun(.seceipDWC

)ii ah/emulovssorG ssorgDWC"rehto"dnallafdniwfomus(.)mc-01foretemaidBIdne-llamsaotemulov

sllafdniW ehtnihtiwelobeertfonoitcesfoah/emulovssorg-foretemaidBIdne-llamsaotttubehtmorftolpaera-dexif

≥ .dawtoorehtrofdetaluclacsiemulovoN.mc01

DWCrehtO aera-dexifehtnihtiweceipah/emulovssorg-foretemaidBIdne-llamsaotnoitauqenailamSnodesabtolp

.mc-01

)iii ah/emulovteNehtnihtiwemulovtenDWCrehtodnallafdniwfomuS.snoitcudedetsawdnaeudisernodesabtolpaera-dexif

a .8891kazoKnodesabsnoitauqerepatllA b .dehcattastoorevahsllafdniW

17



ing occurred. Estimating and testing the statistical signifi-cance of pre-harvest differences, although not definitive,provide insight into the interpretation of post-treatment re-sults and possible impacts on CWD of a mark-to-leave strat-egy (e.g., if the pre-harvest differences were negligible thenthe magnitude and sign of any post-harvest differences mightbe more or less predictive of yarding effects at similar sitesin the same subzone variant and age class). However, owingto a lack of replication of the conventional and mark-to-leave methods at more than one site, analysis of the post-harvesting differences between the two blocks cannot dis-tinguish conclusively between a yarding effect and naturalvariability over space or time ( i.e., post-harvest differencesmay simply reflect natural variability among blocks that wasnot initially evident).

6.1.1 Statistical Methods

In order to classify the CWD pieces by size (diameter andlength), empirical cumulative distribution functions(CDF), $ ( )F x , were calculated based on the diameters andlengths of the pre-harvest CWD pieces. The cumulative distri-bution frequency provides an estimate of the proportion ofCWD pieces (per hectare) that have diameters (or lengths) lessthan or equal to an arbitrary diameter (length) x. Estimates ofthe diameters (lengths) that correspond to the upper 20, 10, 5,2, and 1% of the diameter (or length) distribution were deter-mined by (numerically) inverting $ ( )F x . Pieces with diameters(lengths) corresponding to the upper 10% were classified as �large�.

Volumes of individual trees and pieces of CWD were calculatedusing standard cruise (Kozak 1988) or residue and waste formu-las (e.g., frustrum of a paraboloid), totalled for each sample plot(for each grade and for all grades combined), and divided bythe plot area to obtain an estimate of (tree or CWD) volume perunit area (m3/ha).22 The density of CWD pieces (number ofpieces/ha) was calculated in the same manner (i.e., total numberof pieces in plot/plot area). If a piece of CWD extended be-yond the plot boundary then only that portion contained in theplot was included (e.g., if 45% of the volume lay within theplot then 0.45 x volume was included in the volume total, anda count of 0.45 was added to the total number of pieces). Plot

Table 10. List of attributes used to compare the study blocks prior to harvesting, and corresponding units of measure. a

ssalCeerTeerteritnE

)noitauqerepat(

eceipfonoitroPtolpnihtiw

nailamS()noitauqe

C 2.5±7.21 5.3±8.9

Table 11. Comparison of total gross volume/ha of windfallsfor Tree Class C: cruise taper equation versus Smalianequation of piece within plot.

etubirttA erusaemfostinU

)daed+evil(ytisnedeceipdnaemulovssorgetislatoT m3 ah/ ah/seceip.on

,gnidnatsdaed,evil,.e.i,seitisnedeceipdnasemulovssorglatotatartSdaedlatot,spmuts,DWC

m3 ah/ ah/seceip.on

edarggoldnassalceertyb,semulovtendnassorgesiurclatoT m3 ah/

edarggoldnassalceertyb,eulavesiurclatoT ah/$

)rettebdnaX,U+X,Z,Y,.e.i(edarggolyb,emulovssorgetislatoT m3 ah/

sessalchtgnelyb,retemaid:ytisneddnaemulovDWC m3 ah/ ah/seceip.on

sessalcyacedyb,retemaid:ytisneddnaemulovDWC m3 ah/ ah/seceip.on

)retemaiddnahtgnelrof%01reppu(seceipDWCegraL m3 ah/ ah/seceip.on

yb,seertesiurcnisgolelbatnahcrem-non/eulav-wollatotlaitnetoPsessalchtgneldnaretemaid

m3 ah/ ah/seceip.on

seertesiurcnisgolelbatnahcrem-non/eulav-wolegrallaitnetoP)retemaiddnahtgnelrof%01reppu(

m3 ah/ ah/seceip.on

a sllafdniwfosnoitropgnidulcni,doownwodllasedulcniDWCfonoitinifedehT.sllafdniwdnaseertgnidnatsdaedsedulcnidoowdaedfonoitinifedesiurcehT.esiurcehtniderusaemsllafdniwgnidulcxeDWCsiDWCrehtO.tolpaera-dexifehtni 11elbaT detaluclacemulovllafdniwneewtebecnereffidehtsetartsnomed

.)tolpaera-dexifehtnihtiwllafdniwfonoitrop(noitauqenailamSehtdna)eerteritne(noitauqerepatehtgnisu

22 For each piece, total volume is based on the sum of the individual log volumesrather than the total piece volume. Individual tree and log volumes were compiledby Olympic Resource Management, 300–475 W. Georgia, Vancouver, BC.

18



totals were obtained for each attribute of interest (Table 9). Ze-roes (0 m3/ha or 0 pieces/ha) were recorded for all plots that didnot contain trees or CWD with the applicable attributes.

Basic statistics�sample mean, standard deviation (standard errorof the sample mean, SE), minimum, maximum, coefficient ofvariation (CV), and sample size (number of plots)�were com-piled for all attributes of interest and summarized for the twoharvesting methods.

6.1.2 Tests of Hypotheses

Univariate (i.e., each attribute of interest was tested separately),two-sided t-tests were used to compare the attributes of theConventional and Mark-to-Leave Blocks before harvest.

7 RESULTS

7.1 Selection of CWD Diameter and Length Classes

Tables 12 and 13 present large-end diameter (maximum di-mension) and length percentiles, which are based on the re-spective empirical cumulative distribution frequencies for CWDin individual and combined blocks. The selected diameter andlength classes (Table 14) represent a balance between diam-eter classes used in the studies reported in the literature andthe site-specific cumulative distributions. The classes allow for

comparisons with the data in the literature while providing aclear definition for large CWD pieces.

The diameter classes most commonly applied in the PacificNorthwest are listed in Table 15. For discussion purposes, Table15 also presents the corresponding site-specific cumulative dis-tribution frequency diameter breaks. It is, however, acknowl-edged that the two sets of diameter percentiles are not directlycomparable because the former refer to an �average� diam-eter (e.g., diameter measured at the point of intersection with aline transect), while the latter are based on the large-end inside-bark diameter, which (by definition) exceeds the mean, exceptin those rare cases where all pieces of CWD are cylindrical.

In this study, the 90th percentile of the cumulative distributionfrequency defines the largest diameter class. This is consistentwith the principal underlying the Biodiversity Guidebook (1995)that when managing Wildlife Trees �care should be taken toinclude the upper 10% of the diameter distribution of thestand (taken from cruise data)�� (p. 64). The 70th percentileof the diameter cumulative distribution frequency representsthe break for medium-sized CWD pieces, as it is mid way be-tween the 50th and 90th percentiles. The 50th percentile of thediameter cumulative distribution frequency is the break forthe small-sized CWD pieces. This diameter class corresponds

kcolBydutS

elitnecreP

ht02)m(

ht52)m(

ht03)m(

ht53)m(

ht04)m(

ht54)m(

ht05)m(

ht55)m(

ht06)m(

ht56)m(

ht07)m(

ht57)m(

ht08)m(

ht58)m(

ht09)m(

ht59)m(

ht89)m(

ht99)m(

htoB 6.0 7.0 8.0 1.1 2.1 4.1 6.1 0.2 3.2 6.2 1.3 0.4 9.4 7.6 7.9 4.41 6.22 1.62

evaeL-ot-kraM 7.0 9.0 0.1 1.1 4.1 5.1 9.1 2.2 6.2 0.3 7.3 5.4 2.6 2.8 8.11 9.02 4.52 4.82

lanoitnevnoC 6.0 7.0 7.0 9.0 1.1 2.1 6.1 8.1 2.2 4.2 7.2 4.3 4.4 0.6 1.8 6.11 1.81 8.12

a .tropersihtnidessucsidsessalchtgneldnaretemaidehtenifedotdesusretemaiddnahtgnelehtotrefersrebmunecafdloB

kcolBydutS

elitnecreP

ht02)m(

ht52)m(

ht03)m(

ht53)m(

ht04)m(

ht54)m(

ht05)m(

ht55)m(

ht06)m(

ht56)m(

ht07)m(

ht57)m(

ht08)m(

ht58)m(

ht09)m(

ht59)m(

ht89)m(

ht99)m(

htoB 6.21 6.31 5.41 6.51 0.71 4.81 6.91 1.12 9.32 4.52 9.13 5.53 7.24 1.25 9.26 4.77 4.69 1.901

evaeL-ot-kraM 2.21 9.21 6.31 3.41 1.51 0.61 7.71 4.91 2.12 9.42 3.23 2.53 0.64 5.65 6.66 2.08 3.101 9.901

lanoitnevnoC 2.31 5.41 8.51 4.71 5.81 4.91 6.02 5.22 5.42 6.52 7.03 8.53 8.93 9.84 6.95 1.37 4.19 0.501

a .epytecafdlobnieratnemucodsihtnidetroperataD

Table 12. Cumulative distribution frequencies for CWD length. a

Table 13. Cumulative distribution frequencies for CWD, large-end diameter (inside bark). a

19



to the smallest diameter class discussed in the literature. CWDlength is rarely reported in the literature. For consistency, thelength cumulative distribution frequency breaks coincide withthose used to define the diameter classes.

7.2 Site Overview

Tables 16 and 17, respectively, summarize the estimated totalnumber of pieces/ha and volume/ha partitioned by stratum:live trees, dead trees, stumps, CWD, and total dead wood, to-

gether with their associated standard errors. The total deadwood is the sum of the dead trees, stumps, and CWD. Tables16 and 17 also presents the two-sided p-value (�Prob.�) for as-sessing the statistical significance of the difference betweenthe block means. The p-value is the probability that the magni-tude of the difference between the block sample means wouldbe as large as the observed value, assuming no difference be-tween the population means. The null hypothesis is rejectedwhen the p-value is ≤0.10, which is equivalent to applying a two-sided t-test with significance level α = 0.10. The standard errorof the difference between the two means gives an indication ofthe precision of the estimate or the size of the Type II error (i.e.,the probability that the null hypothesis will not be rejected when itis false). Large standard errors imply that the t-test lacks powerand that only the very large differences will be found to be sta-tistically significant.

7.2.1 Number of Pieces/ha

The total number of pieces/ha is, on average, slightly lower inthe Mark-to-Leave Block stratum than they are in the Con-ventional Block stratum. The two study blocks did not differsignificantly with respect to number of pieces/ha for any stra-tum. However, owing to the high variability, as indicated by thelarge standard error associated with the differences (Table 18),the absence of statistically significant differences is suggestiverather than conclusive evidence that the study blocks were simi-lar prior to harvest.

Over the entire harvesting site, the live trees and CWD repre-sent the bulk (33% and 55%, respectively) of the total numberof pieces. The combined total dead wood represents 67% ofthe total number of pieces/ha on the site, with CWD repre-senting the bulk (77%) of the total dead-wood pieces.

7.2.2 Volume/haVolumes/ha in the Conventional Block strata are generally lowerthan the Mark-to-Leave Block means (Table 18). Total vol-umes/ha for the individual blocks were not significantly dif-ferent for the following strata: live standing trees, dead stand-ing trees, total dead, and total (all strata combined). The stumpand CWD volume/ha were, however, significantly different (p< 0.1) between the two study blocks. In the case of CWD, thisdifference is indicative of differences in the piece-size distri-butions for the two study blocks (see Section 7.5.1 in thisreport). There was high within-block variability for all strata.This finding is not unexpected because natural regenerationand mortality often result in a clumpy distribution of treesand CWD. While total dead-wood volume was not signifi-cantly different between blocks, there was high variability withinblocks and therefore the estimated difference has a large stan-dard error.

Over the entire harvesting site, the live trees represent thebulk of the stand volume, or 70% of the total gross volume/ha. On a volume/ha basis, the total dead wood represents 26%(346 m3/ha) of the total gross volume/ha, and CWD repre-sents 67% (216 m3/ha) of the total gross volume/ha of deadwood. The ratio of live to dead-wood volume/ha is 1:0.34.

retemaraP

ssalcDWCdna,elitnecreP

£ ,07llamS

,09-07muideM

,09>egraL

,59>yreVegraL

dne-egraL)mc(retemaid

£ 03 56-03 56> 57>

)mc(htgneleceiP £ 0.3 01-1.3 01> 41>

Table 14. Diameter and length classes for specific cumulativepercentiles.

ecruoSretemaiD

ssalc)mc(

gnidnopserroCydutsniFDC

)%(8991.lateenotS a 04-12 97-25

08-14 69-97

08> 69>

womyforT&slleW 03-51 96-23

06-03 98-96

06> 98>

0002dragguH b 03-5.21 96-71

05-03 48-96

08-05 69-48

08> 69>

8991remiroL&nrubdooG 02< 25

04-02 97-25

06-04 98-97

06> 98

8991.lateseipS a 03< 96<

06-03 98-96

06> 98>

a .retemaiddne-egraL b .retemaidtcesnarT

Table 15. Examples of diameter classes used in the literature,and the corresponding cumulative diameter distributionpercentages based on study results.

20



7.3 Operational Cruise Summary

7.3.1 Cruise Trees: Gross and Net Volumes

The two study blocks are similar with respect to absolute vol-umes and relative proportions of the five tree classes and loggrades. For this reason, only the combined data are presentedbelow. Total gross volumes from the cruise (i.e., Tree ClassesA+B+C+D+E combined) are presented in Table 18, and netvolumes are in Table 19. The gross and net volumes for TreeClasses A+ B+C combined are comparable to the operationalcruise volumes reported in Table 3.

mutartS

kcolbydutS stolP).on(

gnidnatseviLseert a

)ah/seceip.on(

gnidnatsdaeDseert a

)ah/seceip.on(spmutS b

)ah/seceip.on(DWC c

)ah/seceip.on(daedlatoT d

)ah/seceip.on(latoT

)ah/seceip.on(

htoB 32 0.63±3.134 8.5±2.06 8.62±7.531 1.07±0.076 2.08±9.568 3.79±2.7921

evaeL-ot-kraM 11 4.24±0.583 6.7±6.86 7.42±4.611 0.69±0.606 7.99±0.197 5.711±0.6711

lanoitnevnoC 21 5.65±8.374 4.8±5.25 1.74±3.351 1.301±7.827 3.521±5.439 2.151±3.8041

ecnereffiD 6.07±8.88- 4.11±1.61 2.35±0.73- 9.041±7.221- 1.061±5.341- 4.191±3.232-

eulav-p 6222.0 2071.0 8494.0 7393.0 2083.0 5832.0

a hbdhtiwseertllaedulcnignidnatsdaeDdnaeviL ≥ dnamc01 ≥ .thgiehnim3b seertgnidnatsdnadaederaspmutS ≥ retemaidpotahtiwthgiehnim3<dna3.0 ≥ .mc01c retemaiddne-llamsrohbdarehtiehtiwtolpaera-dexifehtnihtiwseceipdoow-daeddnasllafdniwllafosnoitropsedulcniDWC ≥ .mc01d .DWC+spmuts+seertgnidnatsdaed=daedlatoT

mutartS

kcolbydutS stolP).on(

gnidnatseviLseert b

m( 3 )ah/

gnidnatsdaeDseert b

m( 3 )ah/spmutS c

m( 3 )ah/DWC d

m( 3 )ah/daedlatoT e

m( 3 )ah/latoT

m( 3 )ah/

htoB 32 3.36±5.889 2.61±6.401 3.3±2.52 9.42±9.512 4.43±7.543 3.18±2.4331

evaeL-ot-kraM 11 2.49±3.0001 6.32±1.501 2.4±8.81 7.24±0.772 8.26±0.104 9.531±3.1041

lanoitnevnoC 21 2.98±6.779 3.32±1.401 6.4±0.13 9.71±9.951 9.72±0.592 0.69±6.2721

ecnereffiD 7.921±7.22 2.33±0.1 3.6±2.21- 3.64±2.711 7.86±0.601 4.661±7.821

eulav-p 8268.0 5579.0 0660.0 4910.0 7731.0 8744.0

a naroftnereffidyltnacifingis=epytecafdloB α .01.0=b hbdhtiwseertllaedulcnignidnatsdaeDdnaeviL ≥ dnamc01 ≥ .thgiehnim3c seertgnidnatsdnadaederaspmutS ≥ retemaidpotahtiwthgiehnim3<dna3.0 ≥ .mc01d retemaiddne-llamsrohbdarehtiehtiwtolpaera-dexifehtnihtiwseceipdoow-daeddnasllafdniwllafosnoitropsedulcniDWC ≥ .mc01e .DWC+spmuts+seertgnidnatsdaed=daedlatoT

Tree Class A represented 89% (982 m3/ha) of the total grossstem volume, with Tree Classes B and D representing muchof the remainder (104 m3/ha). Tree Class D, the volume ofwhich is generally not reported in operational cruise compila-tions, represents 6% of the gross stem volume (64 m3/ha).There were no trees in Tree Class E.

The higher grade logs (H+I+J combined) represented 50%(550 m3/ha) of the total gross cruise volume. Utility Gradelogs (X+U combined) represented 12% (136 m3/ha), and thelow-value/non-merchantable wood (Y+Z combined) repre-sented 34% (374 m3/ha) of the total. One third of the Y

Table 16. Total site density, by stratum (mean ± SE). a

Table 17. Total gross site volume, by stratum (mean ± SE). a

21



Grade volume might be considered pulp (i.e., comprises woodthat is ≥80% sound)23. Stumps and tops combined represented4% of the total gross cruise volume.

Close to 100% of the volume in the higher log grades (H+I+Jcombined) was in Tree Class A. Similarly, 98% of the gross vol-ume in the Utility Grades (U+X combined) was in Tree Class A.Tree Classes B and C included only 2% of the mean total Utility-Grade gross volume. Tree Classes B and C include only 6 m3/ha of gross volume in Utility-Grade-and-better (X grade and bet-ter). Tree Class D did not include Utility-Grade-and-better logs.

On average, 78% of the Y Grade gross volume was in TreeClass A. Tree Classes B, C, and D combined represented 22%of the total Y Grade volume, with 98% of this volume beingin the lower end of the range in terms of quality (<80% sound)and value. (Upper-range Y Grade wood, i.e., ≥80% sound, oc-curred only in Tree Classes B and C. The Z Grade wood vol-

ume was present only in Tree Class D).

7.3.2 Cruise Values

Table 20 presents average market value of logs ($/ha) by treeclass and log grade. These values are based on average log pricesfor the Vancouver market for the six months ending 15 October2000 as determined by the Council of Forest Industries24.

Tree Class A represented 96% of the estimated total cruise value(Table 21). The highest graded logs represented 71% of the totalcruise value. The Utility Grade logs (X+U combined) represented

goLroedargyrogetac

ssalCeerT a yrogetacssalCeerT b

latoTm( 3 )ah/

)%(

Am( 3 )ah/

)%(

Bm( 3 )ah/

)%(

Cm( 3 )ah/

)%(

Dm( 3 )ah/

)%(

Em( 3 )ah/

)%(

dezisrednUevil+daed

seert c

m( 3 )ah/)%(

C+Bm( 3 )ah/

)%(

E+Dm( 3 )ah/

)%(

C+B+Am( 3 )ah/

)%(

J+I+H 9.63±6.745 7.0±1.1 8.0±3.1 0.0±0.0 0.0±0.0 0.0±0.0 1.1±5.2 0.0±0.0 7.63±1.055 7.63±1.055

94 0 0 0 0 0 0 0 05 05

U+X 2.31±2.231 0.1±4.1 6.1±2.2 0.0±0.0 0.0±0.0 0.0±0.0 8.1±6.3 0.0±0.0 3.31±8.531 3.31±8.531

21 0 0 0 0 0 0 0 21 21

Y(≥ %08

)dnuos

4.61±3.988

9.0±9.10

8.1±6.20

0.0±0.00

0.0±0.00

0.0±0.00

9.1±4.40

0.0±0.00

1.61±8.398

1.61±8.398

Y%08<()dnuos

8.32±1.97161

9.01±3.433

6.3±6.51

6.6±4.923

0.0±0.00

0.0±0.00

9.21±9.934

6.6±4.923

1.82±0.91202

5.92±.4.84222

Y 7.82±5.862 1.11±1.63 9.3±2.8 6.6±4.92 0.0±0.0 0.0±0.0 9.21±3.44 6.6±4.92 9.33±8.213 2.63±2.243

42 3 1 3 0 0 4 3 82 13

Z 0.0±0.0 2.0±2.0 3.0±3.0 0.8±3.13 0.0±0.0 0.0±0.0 4.0±6.0 0.8±3.13 4.0±6.0 9.7±9.13

0 0 0 3 0 0 0 3 0 3

Z+Y 7.82±5.862 2.11±3.63 9.3±5.8 6.01±8.06 0.0±0.0 0.0±0.0 0.31±9.44 6.01±8.06 9.33±3.313 4.63±1.473

42 3 1 5 0 0 4 5 82 43

spmutSspot&

4.4±1.433

5.0±9.10

2.0±7.00

6.0±5.30

0.0±0.00

1.1±4.71

6.0±6.20

6.0±5.30

6.4±7.633

9.4±7.744

latoT 4.36±4.289 7.11±7.04 2.5±7.21 2.11±3.46 0.0±0.0 1.1±4.7 9.31±5.35 2.11±3.46 8.56±9.5301 9.96±6.7011

98 4 1 6 0 1 5 6 39 001a EotAsessalCeerTsedulcniesiurC ≥( dnahbdmc5.71 ≥ .)llatm3b .sessalceertfosnoitpircsedrof8elbaTeeSc .hbdmc4.71ot01=seertdezisrednU

Table 18. Gross cruise a volume, by tree class and log grade: both study blocks combined (mean ± SE).

23 Much of the ≥80% group gross volume is better than 80% sound. On averagethe <80% sound group gross volume is close to 50% sound. Factors such aspiece size and market conditions would determine whether or not the <80%group net volume would be used as pulp.24 Jim Wilson, Manager, Cruise Compilation Department, Olympic ResourceManagement, 300–475 W. Georgia Street, Vancouver, BC; personal communi-cation, March 2001.

22



11% of the total, while Y Grade logs represented 18% of thetotal cruise value. The value of the Y Grade logs was fairly evenlydivided between the two classes of Y Grade.

For this stand, the value of the total dead stem wood (Tree ClassesB+C+D combined) was <4% of the total cruise value, with <1%of the total dead stem value in Utility-Grade-and-better logs (XGrade and better). Utility-Grade-and-better logs represented 6 m3/ha, which is well within the avoidable waste benchmark volumes.The total dead stem wood gross volume, however, is only equal to118 m3/ha. This is approximately one-third of the gross volumeof the combined Y and Z grade logs (374 m3/ha).

7.4 Total Gross Site Volume, by Stratum and Log Grade

Table 22 summarizes the differences between gross and netvolumes/ha of the study blocks by log grade. Because therewere no significant differences between blocks (i.e., Prob. >>0.1),

the total gross volume partitioned by grade is presented for thecombined blocks in Tables 23 and 24 (data for individual blocksare provided in Appendix C). The small sample sizes precludetesting for significant differences for all grades. Figure 7 is avisual presentation of Table 23.

The total gross volumes and net volumes for Utility-Grade-and-better (H+I+J and X+U categories) and for low-value/non-merchantable grades (Y+Z combined) were not signifi-cantly different between blocks. For the combined blocks, totalgross volume of low-value/non-merchantable wood was 599m3/ha, which represents 46% of gross volume/ha for the to-tal site (based on Table 22 which excludes stumps and tops).

The live trees, i.e., Tree Class A, represent the highest source ofY+Z volume. The total volume/ha for Y+Z wood is partitionedas follows: Tree Class A, 45%; Tree Classes B+D combined,16%; CWD (C+E+other combined) 35%; and stumps, 4%.

goLroedargyrogetac

ssalCeerT a yrogetacssalCeerT b

latoTm( 3 )ah/

)%(

Am( 3 )ah/

)%(

Bm( 3 )ah/

)%(

Cm( 3 )ah/

)%(

Dm( 3 )ah/

)%(

Em( 3 )ah/

)%(

dezisrednUevil+daed

seert c

m( 3 )ah/)%(

C+Bm( 3 )ah/

)%(

E+Dm( 3 )ah/

)%(

C+B+Am( 3 )ah/

)%(

J+I+H 9.33±6.705 7.0±0.1 7.0±3.1 0.0±0.0 0.0±0.0 0.0±0.0 0.1±3.2 0.0±0.0 7.33±9.905 7.33±9.905

95 0 0 0 0 0 0 0 06 06

U+X 9.11±5.321 9.0±3.1 4.1±0.2 0.0±0.0 0.0±0.0 0.0±0.0 6.1±2.3 0.0±0.0 9.11±8.621 9.11±8.621

41 0 0 0 0 0 0 0 51 51

Y(³ %08

)dnuos

7.41±9.1801

8.0±6.10

6.1±3.20

0.0±0.00

0.0±0.00

0.0±0.00

7.1±8.30

0.0±0.00

5.41±7.5801

5.41±7.5801

Y%08<()dnuos

7.21±5.8921

1.6±6.812

5.2±9.30

8.2±5.111

0.0±0.01

0.0±0.00

3.7±5.223

8.2±5.111

0.61±9.02141

6.61±4.23151

Y 8.91±3.081 3.6±1.02 8.2±2.6 8.2±5.11 0.0±0.0 0.0±0.0 4.7±3.62 8.2±5.11 5.32±6.602 5.42±1.812

12 2 1 1 0 0 3 1 42 62

Z 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0

0 0 0 0 0 0 0 0 0 0

Z+Y 8.91±3.081 3.6±1.02 8.2±2.6 8.2±5.11 0.0±0.0 0.0±0.0 4.7±3.62 8.2±5.11 5.32±6.602 5.42±1.812

12 2 1 1 0 0 3 1 42 62

spmutSspot&

0.0±0.00

0.0±0.00

0.0±0.00

0.0±0.00

0.0±0.00

0.0±0.00

0.0±0.00

0.0±0.00

0.0±0.00

0.0±0.00

latoT 4.25±5.118 4.6±4.22 1.4±4.9 8.2±5.11 0.0±0.0 0.0±0.0 0.8±8.13 8.2±5.11 7.35±3.348 9.45±8.458

59 3 1 1 0 0 4 1 99 001a EotAsessalCeerTsedulcniesiurC ³( dnahbdmc5.71 ³ .)llatm3b .sessalceertfosnoitpircsedrof8elbaTeeSc .hbdmc4.71ot01=seertdezisrednU

Table 19. Cruise a net volume, by tree class and log grade: both study blocks combined (mean ± SE).

23



7.5 “Potential” Sources of Post-Harvest CWD:Attributes of Pre-Harvest CWD and Low-Value/Non-Merchantable Wood in the Stand

Potential sources of post-harvest CWD on site prior to har-vesting include:

1. low-value/non-merchantable wood in dead down trees(i.e., Tree Classes C and E) and other CWD pieces, and

2. low-value/non-merchantable wood in standing live anddead trees (i.e., Tree Classes A, B, and D).

For the purpose of this report all non-merchantable wood (i.e.,wood quality less than the criteria for Y Grade) has been clas-sified as Z grade wood. As shown in Table 23 less than 10 m3/ha of original CWD was classified as Tree Class C 25. Y and ZGrade wood comprised almost all of this volume. Because

edarGgoLyrogetacro

ssalCeerT a yrogetacssalCeerT a

latoT)ah/0001$(

A)ah/0001$(

B)ah/0001$(

C)ah/0001$(

D)ah/0001$(

E)ah/0001$(

dezisrednUevil+daed)ah/0001$(

C+B)ah/0001$(

E+D)ah/0001$(

C+B+A)ah/0001$(

J+I+H 7.2±1.73 0.0±1.0 0.0±1.0 0.0±0.0 0.0±0.0 0.0±0.0 1.0±1.0 0.0±0.0 7.2±3.73 7.2±3.73

U+X 5.0±4.5 0.0±1.0 1.0±1.0 0.0±0.0 0.0±0.0 0.0±0.0 1.0±2.0 0.0±0.0 5.0±5.5 5.0±5.5

Y (³ )dnuos%08 6.0±6.3 0.0±1.0 1.0±1.0 0.0±0.0 0.0±0.0 0.0±0.0 1.0±2.0 0.0±0.0 6.0±7.3 6.0±7.3

Y )dnuos%08<( 6.0±3.4 3.0±8.0 1.0±2.0 1.0±5.0 0.0±0.0 0.0±0.0 3.0±0.1 1.0±5.0 7.0±3.5 8.0±9.5

Y 8.0±9.7 3.0±9.0 1.0±3.0 1.0±5.0 0.0±0.0 0.0±0.0 3.0±2.1 1.0±5.0 0.1±1.9 0.1±6.9

Z 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0

Z+Y 8.0±9.7 3.0±9.0 1.0±3.0 1.0±5.0 0.0±0.0 0.0±0.0 3.0±2.1 1.0±5.0 0.1±1.9 0.1±6.9

spmutS & spot 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0 0.0±0.0

latoT 3.3±4.05 3.0±0.1 2.0±4.0 1.0±5.0 0.0±0.0 0.0±0.0 4.0±5.1 1.0±5.0 3.3±9.15 3.3±4.25

a .sessalCeerTfosnoitpircsedrof8elbaTeeS

Table 20. Market value, by tree class and log grade: both study blocks combined (mean ± SE).

roedarGgoLyrogetac

ssalCeerT a

ssalCeerTyrogetac a

latoT)%(

A)%(

B)%(

C)%(

D b

)%(C+B)%(

C+B+A)%(

J+I+H 17 0 0 0 0 17 17

U+X 01 0 0 0 0 11 11

(Y ³ )dnuos%08 7 0 0 0 0 7 7

)dnuos%08<(Y 8 2 0 1 2 01 11

Y 51 2 1 1 2 71 81

Z 0 0 0 0 0 0 0

Z+Y 51 2 1 1 2 71 81

spotdnaspmutS 0 0 0 0 0 0 0

latoT 69 2 1 1 3 99 001

a .sessalCeerTfosnoitpircsedrof8elbaTeeSb .EssalCeerTniseertonerewerehT

Table 21. % of total market value, by log grade and treeclass: both study blocks combined.

dna,elbairaVkcolbyduts stolP

).on(

yrogetacedarGgoL

J+I+Hm( 3 )ah/

U+Xm( 3 )ah/

Z+Ym( 3 )ah/

emuloV

htoB 32 7.63±4.055 3.31±8.731 1.74±6.995

evaeL-ot-kraM 11 1.65±3.775 2.61±9.631 7.58±9.636

lanoitnevnoC 21 5.94±7.525 8.12±7.831 2.64±4.565

ecnereffiD 8.47±6.15 3.72±8.1- 8.79±5.17

eulav-p 9794.0 8749.0 8074.0

emulovteN

htoB 32 7.33±3.015 0.21±1.921 7.42±7.232

evaeL-ot-kraM 11 5.05±7.135 6.51±8.131 7.44±8.042

lanoitnevnoC 21 6.64±7.094 7.81±6.621 5.52±2.522

ecnereffiD 7.86±0.14 4.42±3.5 4.15±7.51

eulav-p 4755.0 5138.0 9367.0

a seertdaeddnaevilgnidnats,.e.i,32elbaTrepsaatartsllasedulcni22elbaTspmutsdna,)"rehto"dnaE+CsessalceerT(DWC,)spotdnaspmutstpecxe(

.)m0.3<sganstrohs(

Table 22. Total gross site volume and net site volume, for allstrata combined (excluding stumps and tops) (mean ± SE). a

24



Figure 5. Total gross site volume, by stratum and log grade.

0255075

100125150175200225250275300325350375400425450475500525550575600625650

H+I+J X+U Y+Z Stumps and tops

Log Grade or category

Gro

ss s

ite v

olum

e (m

3/ha)

Stumps (0.3-2.99 m tall)

Other CWD

Undersized live & dead trees

Tree Class Category C+E

Tree Class D

Tree Class B

Tree Class A

45%

6%

10%

34%

4%

yrogetaC a

yrogetacedarggoL

latoTm( 3 )ah/

J+I+Hm( 3 )ah/

U+Xm( 3 )ah/

Z+Ym( 3 )ah/

spmutS d

spotdnam( 3 )ah/

metSeviL-AssalCeerT 9.63±6.745 3.31±3.231 7.82±5.862 4.4±1.43 4.36±5.289

)dnuos%05>(gnidnatSlaitnetoPdaeD-BssalCeerT 7.0±1.1 0.1±4.1 2.11±3.63 4.0±8.1 6.11±7.04

)dnuos%05<(gnidnatSsselesUdaeD-DssalCeerT 0.0±0.0 0.0±0.0 7.01±7.95 6.0±4.3 3.11±1.36

seertevil+daeddezisrednU b 0.0±0.0 0.0±0.0 0.0±0.0 1.1±2.7 1.1±2.7

DWC

)denibmocE+CsessalCeerT(sllafdniW c 0.0±0.0 9.0±6.1 1.3±1.8 0.0±0.0 5.3±8.9

seceiPDWCrehtO 9.0±7.1 2.1±3.2 9.22±0.202 0.0±0.0 0.32±0.602

)llatm0.3<(spmutS f 0.0±0.0 1.0±2.0 3.3±0.52 0.0±0.0 3.3±2.52

latoT 7.63±4.055 3.31±8.731 1.74±6.995 8.4±6.64 3.18±4.4331a .sessalceerts'resueahreyeWfosnoitinifedrof8elbaTeeSb .hbdmc4.71-01=seertdezisrednUc noitroptahtsiDWCotdengissaemulovehtEdnaCsessalCeerTroF.EdnaCsessalCeerTsahcusseertnellafdaeddedulcniDWCfonoitinifedlacigoloceehT

.eerteritneehtnodesaberaEdnaCsessalCeerTrofsemulovesiurceht,tsartnocnI.eerteritneehtton,tolpehtnihtiwgolfod gnidnatsdaedfom3.0<,.e.i,pmutsehtedulcnitonseodtI.seertdaeddnaevilgnidnatshtobrofthgiehnim3.0<elobeertehtfonoitropehtotsreferpmutsA

erahcihwsmets ≥ .)FetontooFees(pmutssaotderrefererasganstrohseseht,tropersihtnI.sganstrohs,.e.i,thgiehnim3<dnam3.0e .edargZasadeifissalcsawedargrettebroYafoairetircehtgniteemtondoownwoddaed,ydutstolipehtfoesoprupehtroFf anipmutsasadedrocersitub,esiurclanoitareponanidedrocertonsithgiehnim0.3<eertdaedaesuacebpmutsasaotderrefersiganstrohsatropersihtnI

.yevruSetsaWdnaeudiseR

Table 23. Total gross site volume partitioned by tree class, stratum, and log grade: both study blocks combined (mean ± SE).

25



only 1% of the pre-harvest CWD was Utility-Grade-and-bet-ter, the following paragraphs discuss the attributes of all theCWD as a whole, i.e., windfalls and �other� CWD combined.

7.5.1 Attributes of Pre-Harvest CWD

Diameter and Length Classes

Tables 25 and 26, respectively, present the diameter and lengthclass means and standard errors of the number of pieces/haand volume/ha, and the corresponding percentages of the to-tals. Tables 25 and 26 also present the p-values for comparingblocks in terms of differences in the total density and totalvolume/ha in each diameter and length class.

Even though the total number of pieces/ha did not differ sig-nificantly between blocks, the diameter and length distributionsvary. The Conventional Block had a slightly higher density ofpieces in the ≤3-m length class and in the ≤30-cm diameter class.The Mark-to-Leave Block had a higher density of pieces in the>10-m and >14-m length classes, in particular pieces with alarge-end diameter >65 cm. The differences between blocks werestatistically significant for the >14-m length class total. The highwithin-block variability may, however, obscure other differences;in particular, differences in the total density of pieces ≤3 m long.

As expected, the smallest diameter and length classes representfrom 65 to 84% of the total number of pieces/ha. The largestdiameter pieces (large-end diameter >65 cm) represent 9�11%,

while the longer pieces (>10 m long) represent 7�12% of thetotal pieces/ha. Those pieces with a large-end diameter >65cm and a length >10 m represent 2�5% of the total numberof pieces/ha. This component translates into an average of 12and 32 pieces/ha for the Conventional and Mark-to-LeaveBlocks respectively.

The total volume for the Conventional Block was significantlylower than the total volume for the Mark-to-Leave Block. Thisdifference largely reflects the significantly higher mean vol-ume/ha in the >10-m length and >65-cm large-end diameterclasses of the Mark-to-Leave Block compared to the Conven-tional Block. For the Mark-to-Leave Block, volume/ha in theclass combining the above diameter and length classes wasnoticeably higher than mean for the Conventional Block. Theabove finding reflects a higher density of large pieces, in par-ticular long pieces, in the Mark-to-Leave Block. The meanvolume/ha in the smallest diameter and length classes weregenerally comparable between the two blocks.

As expected, the larger diameter and longer length classes repre-sent much of the total volume/ha. The smallest diameter andshortest length classes represented <15% of the total block vol-umes/ha. The larger diameter classes (>65-cm large-end diam-eter) represented 53�71% and, the upper length classes (>10 mlong) represented 54�70%, of the total volume/ha, respectively,for the Conventional and Mark-to-Leave Blocks. Together theseclasses represented 31% of the total mean volume/ha for theConventional Block, and 56% for the Mark-to-Leave Block. Thesevalues correspond to an average 50 m3/ha for the Conventional25 There were no trees in Tree Class E.

yrogetaC a

yrogetacedarggoL

Z+Yfo%(

niemulov)yrogetac

J+I+Hfo%(

).lovlatot

U+Xfo%(

).lovlatot

Z+Yfo%(

).lovlatot

spmutS d

spotdnafo%(

).lovlatot

latoTfo%(

.lovlatot

metSeviL-AssalCeerT 14 01 02 3 47 54

)dnuos%05>(gnidnatSlaitnetoPdaeD-BssalCeerT 0 0 3 0 3 6

)dnuos%05<(gnidnatSsselesUdaeD-DssalCeerT 0 0 4 0 5 01

seertevil+daeddezisrednU b 0 0 0 1 1 0

DWC

)denibmocE+CsessalCeerT(sllafdniW c 0 0 1 0 1 1

seceiPDWCrehtO 0 0 51 0 51 43

)llatm0.3<(spmutS 0 0 2 0 2 4

latoT 14 01 54 4 001 001a .sessalceerts'resueahreyeWfosnoitinifedrof8elbaTeeSb .hbdmc4.71ot01=seertdezisrednUc noitroptahtsiDWCotdengissaemulovehtEdnaCsessalCeerTroF.EdnaCsessalCeerTsahcusseertnellafdaeddedulcniDWCfonoitinifedlacigoloceehT

.eerteritneehtnodesaberaEdnaCsessalCeerTrofsemulovesiurceht,tsartnocnI.eerteritneehtton,tolpehtnihtiwgolfod spmutsgnidnatsdaedsedulcxe;seertnellafdnagnidnatsedulcnispmutS ≥ .)sganstrohs,.e.i(thgiehnim0.3<dnam3.0e .edargZasadeifissalcsawedargrettebroYafoairetircehtgniteemtondoownwoddaed,ydutstolipehtfoesoprupehtroF

Table 24. % of total gross site volume, by stratum and log grade: both study blocks combined.

26



Block and 153 m3/ha for the Mark-to-Leave Block. The highervolumes in the Mark-to-Leave Block do not appear to be relatedto the different timber types in the blocks.

Diameter and Decay Classes

Tables 27 and 28 present CWD density and volume/ha bydiameter and decay classes. The broad groupings for decayclass are similar to those proposed by Parks et al. (1997). Abrief description from Parks et al. (1997) follows:

� Slightly Decayed logs represent those trees that have justfallen over, retain their bark and branches, have little decayin the wood, and are resting largely above the ground

� Moderately Decayed logs represent those logs that are incontact with the ground, have lost some of their bark andbranches, and have some decay in the wood.

� Well Decayed logs represent those logs that have begundecomposing into the forest floor, are not intact, are exten-sively decayed, and lack both limbs and bark.

For both study blocks, ≥90% of pieces and volume was Mod-erately to Well Decayed, although the relative proportions inDecay Classes 3 and 4+5 differed between study blocks.

The Conventional Block had a significantly higher total densityof pieces in Decay Classes 4+5 combined (67%) compared tothe Mark-to-Leave Block (34%). This trend was observed inall diameter classes but was most noticeable for pieces with asmall or medium large-end diameter (i.e., <65 cm at the largeend). In contrast, the Mark-to-Leave Block had a high, althoughnot significantly high, total density of pieces in Decay Class 3(56%). The greater density was most noticeable for the smalland large diameter classes.

retemaiDssalc

kcolbydutS ≤≤≤≤≤ m3)ah/seceip.on(

)%(

m01-3)ah/seceip.on(

)%(

m01>)ah/seceip.on(

)%(

m41>)ah/seceip.on(

)%(

latoT)ah/seceip.on(

)%(

ecnereffiD)ah/seceip.on(

eulav-p

≤ mc03 evaeL-ot-kraM 4.18±0.343 6.41±3.66 9.6±0.9 9.0±5.1 0.58±3.814 0.221±0.09- 8864.0

75 11 1 0 96

lanoitnevnoC 9.18±6.534 2.21±5.85 5.4±1.41 2.1±3.1 5.78±2.805

06 8 2 0 07

mc56-03 evaeL-ot-kraM 6.12±2.14 4.5±5.64 3.8±2.43 1.8±9.12 3.92±9.121 4.53±1.63- 1913.0

6 8 6 4 02

lanoitnevnoC 3.02±3.68 4.5±5.74 2.4±2.42 6.2±9.21 8.91±9.751

11 7 3 2 12

mc56> evaeL-ot-kraM 4.4±3.9 8.5±7.42 7.4±0.23 9.4±1.62 3.21±9.56 1.41±4.3 0218.0

2 4 5 4 11

lanoitnevnoC 4.3±1.41 6.6±2.63 5.3±2.21 9.2±1.7 9.6±5.26

2 5 2 1 9

mc57> evaeL-ot-kraM 6.2±6.3 3.4±0.02 0.4±1.52 8.3±3.12 4.8±8.84 5.9±3.41 3841.0

1 3 4 3 8

lanoitnevnoC 1.2±3.6 9.4±2.91 8.2±1.9 0.2±1.5 4.4±5.43

1 3 1 1 5

latoT evaeL-ot-kraM 1.98±5.393 4.71±4.731 2.21±1.57 9.01±5.94 0.69±0.606

56 32 21 8 001

lanoitnevnoC 7.59±9.535 7.91±3.241 5.8±5.05 0.5±2.12 1.301±7.827

37 02 7 3 001

ecnereffiD 7.031±5.241- 3.62±8.4- 9.41±6.42 0.21±3.82 9.041±7.221-

eulav-p 1882.0 7558.0 6311.0 0820.0 7393.0

a seulav-p naroftnereffidyltnacifingiseraecafdlobcilatini α rofgnitsetdedulcerpeziselpmaS.rehgihylbaecitoneraepytecafdlobnismetI.1.0=.secnereffidtnacifingis

Table 25. Density of CWD (includes Tree Classes C+E + other combined), partitioned by diameter and length classes(mean ± SE).a

27



The total volumes for Decay Classes 4+5 combined were com-parable for the two blocks. Even though the total density of DecayClass 3 in Conventional Block was significantly higher than thatfor the Mark-to-Leave Block, the pieces in the Mark-to-LeaveBlock were larger in comparison. Therefore, the Mark-to-LeaveBlock has fewer but larger Well-Decayed pieces. For the Mark-to-Leave Block, the total volume/ha in Decay Class 3 was also sig-nificantly higher than the mean in Conventional Block. This dif-ference was due to the higher total density, and a higher density oflarger diameter pieces, associated with the Mark-to-Leave Block.

7.5.2 Potential Low-Value/Non-Merchantable Wood inTree Classes A, B, and D

Tables 29 and 30, respectively, present by block the densityand volume of pieces derived from standing live and deadtrees by grade. Small sample sizes preclude significance testing

for each grade, diameter, and length combination. However, nei-ther the mean density nor the volume/ha of the potential low-value/non-merchantable large pieces (i.e., >65 cm at the large-end and >10 m in length) derived from Tree Classes A, B andD is significantly different between the two blocks (Table 31).

The mean density for the >65 cm and >10 m potential low-value/non-merchantable wood (i.e., Grades Y+Z combined)derived from Tree Classes A, B, and D combined is 29 pieces/ha for the Mark-to-Leave Block and 31 pieces/ha for theConventional Block. The mean volume/ha for these largerlow-value/non-merchantable pieces is 207 m3/ha for the Mark-to-Leave Block, and 252 m3/ha Conventional Block.

The potential availability of large-sized Utility-Grade logs (U+XGrades combined) in Tree Classes A, B, and D combined, isnoticeably lower than that of the combined Y+Z Grade logs.

Table 26. Volume of CWD (includes Tree Classes C+E + other combined), partitioned by diameter and length classes(mean ± SE). a

retemaiDssalc kcolbydutS

≤≤≤≤≤ m3)ah/seceip.on(

)%(

m01-3)ah/seceip.on(

)%(

m01>)ah/seceip.on(

)%(

m41>)ah/seceip.on(

)%(

latoT)ah/seceip.on(

)%(ecnereffiD

)ah/seceip.on( eulav-p

≤ mc03 evaeL-ot-kraM 4.1±4.5 6.1±0.7 6.1±3.2 5.0±8.0 5.3±7.41 6.4±0.4- 7393.0

2 2 1 0 5

lanoitnevnoC 1.1±5.6 0.2±2.7 9.1±9.4 4.0±4.0 0.3±7.81

4 5 3 0 21

mc56-03 evaeL-ot-kraM 3.1±3.4 6.4±4.42 1.6±5.73 5.5±0.22 9.7±1.66 9.01±0.9 0514.0

2 9 31 8 42

lanoitnevnoC 0.1±3.8 2.2±0.71 5.6±8.13 0.5±0.22 5.7±1.75

5 11 02 41 63

mc56> evaeL-ot-kraM 7.1±7.3 4.41±8.83 0.72±8.351 6.62±7.141 4.83±3.691 0.14±1.211 5210.0

1 41 65 15 17

lanoitnevnoC 1.1±7.3 4.7±2.13 2.61±2.94 2.51±5.73 6.41±2.48

2 91 13 32 25

mc57> evaeL-ot-kraM 1.1±5.1 1.11±7.23 0.42±3.921 2.32±7.021 7.23±5.361 2.53±9.101 6800.0

1 21 74 44 95

lanoitnevnoC 4.0±1.1 2.5±4.91 8.31±1.14 2.21±4.03 0.31±6.16

1 21 62 91 93

latoT evaeL-ot-kraM 1.3±3.31 6.71±2.07 8.82±5.391 1.72±5.461 7.24±0.772

5 52 07 95 001

lanoitnevnoC 3.2±4.81 9.9±5.55 5.91±0.68 4.71±9.95 9.71±9.951

11 53 45 73 001

ecnereffiD 8.3±1.5- 2.02±7.41 7.43±6.701 2.23±6.401 3.64±2.711

eulav-p 2991.0 5574.0 5500.0 8300.0 4910.0a seulav-p naroftnereffidyltnacifingiseraecafdlobcilatini α rofgnitsetdedulcerpeziselpmaS.rehgihylbaecitoneraepytecafdlobnismetI.1.0=

.secnereffidtnacifingis

28



The mean density of large Utility-Grade logs is 8 and 5 pieces/ha respectively for the Mark-to-Leave and Conventional Blocks.The corresponding mean volume for these large Utility-Gradelogs is 41 and 23 m3/ha respectively for the Mark-to-Leaveand Conventional Blocks (Tables 29 and 30).

8 DISCUSSION AND CONCLUSIONS

8.1 Potential Sources of CWD

Under the current provincial utilization standards for the Brit-ish Columbia Coast (BCMOF 1997), opportunities for Licens-ees to leave wood in the setting without monetary billing are

strongly tied to the timber attributes and pulp market prices.The stand must include low-value/non-merchantable wood, i.e.,Y and Z Grade pieces, and market prices must be low enoughthat leaving pulp wood in the setting is more economical thanyarding and processing the logs. The pilot site was chosen forstudy because the stand contained considerable decay and po-tential waste. At the time of the study, Y and Z Grade logs andbenchmark wood volumes were being left on site as part ofWeyerhaeuser�s standard operations26.

Based on the review of the attributes (i.e., size and volume) oflow value/non-merchantable wood in the pre-harvest CWDand standing timber, it appears that, for the pilot site, there is apotential in the Mark-to-Leave Block to retain, at the time of

Table 27. Density of CWD (includes Tree Classes C+E + other combined), partitioned by diameter and decay classes(mean ± SE).

ssalcretemaiD kcolbydutS

ssalCyaceD

latoT)ah/seceip.on(

)%(

,2+1deyaceDylthgilS)ah/seceip.on(

)%(

,3deyaceDyletaredoM

)ah/seceip.on()%(

,5+4deyaceDlleW)ah/seceip.on(

)%(

≤ mc03 evaeL-ot-kraM 5.12±3.04 7.85±2.262 2.83±8.511 0.58±3.814

7 34 91 96

lanoitnevnoC 9.11±7.53 5.85±9.841 9.58±7.323 5.78±2.805

5 12 44 07

mc56-03 evaeL-ot-kraM 4.8±7.61 8.61±9.15 2.8±3.35 3.92±9.121

3 8 9 02

lanoitnevnoC 4.2±3.5 3.4±1.93 9.12±6.311 8.91±9.751

1 5 61 22

mc56> evaeL-ot-kraM 3.1±0.2 5.6±5.72 8.6±5.63 3.21±9.56

0 5 6 11

lanoitnevnoC 6.0±7.0 4.3±9.9 0.8±9.15 9.6±5.26

0 1 7 8

mc57> evaeL-ot-kraM 0.1±0.1 5.4±8.91 1.5±9.72 4.8±8.84

0 3 5 8

lanoitnevnoC 6.0±6.0 5.2±9.4 2.5±9.82 4.4±5.43

0 1 4 5

latoT evaeL-ot-kraM 1.22±0.95 5.36±5.143 6.24±6.502 0.69±0.606

01 65 43 001

lanoitnevnoC 1.31±7.14 8.06±9.791 2.101±1.984 1.301±7.827

6 72 76 001

ecnereffiD 7.52±3.71 9.78±6.341 8.901±6.382- 9.041±7.221-

eulav-p 6705.0 1711.0 3710.0 7393.0a seulav-p naroftnereffidyltnacifingiseraecafdlobcilatini α gnitsetdedulcerpeziselpmaS.rehgihylbaecitoneraepytecafdlobnismetI.1.0=

.secnereffidtnacifingisrof

29



harvest, dead down wood volumes that are comparable to theoriginal pre-harvest total dead wood volume. This assertion isbased on the following:

� The estimated pre-harvest total gross volume/ha of low-value/non-merchantable wood (Y+Z Grades combined) forall strata is three quarters higher than the total pre-harvestdead wood volume (599 vs. 346 m3/ha).

� Approximately two-thirds of the pre-harvest total grossvolume of low-value/non-merchantable wood is derivedfrom the live and dead standing trees. As a general rule, thissource of dead wood will be less susceptible to breakagethan Moderately Decayed or Well-Decayed CWD on theground at the time of harvest.

� The volume and density of large-sized (i.e., ≥65 cm at thelarge-end and ≥10 m in length) low-value/non-merchant-able wood (Grades Y and Z combined) in the standing liveand dead trees, is estimated at densities and volumes/hacomparable to, or higher than those of the pre-harvest CWD.

The above estimates of the pilot site�s pre-harvest attributesare at best an approximation of the total, low-value/non-mer-chantable wood that can potentially be retained at the time ofharvest. In fact, only a portion of this �potential� wood will beleft��even in the Mark-to-Leave Block, where Y and Z Gradesof wood are bucked off and marked to leave. Numerous fac-

Table 28. Volume of CWD (includes Tree Classes C+E + other combined), partitioned by diameter and decay classes (mean ± SE).

ssalcretemaiD kcolbydutS

ssalCyaceD

latoTm( 3 )ah/

)%(

,2+1deyaceDylthgilS

m( 3 )ah/)%(

,3deyaceDyletaredoM

m( 3 )ah/)%(

,5+4deyaceDlleW

m( 3 )ah/)%(

≤ mc03 evaeL-ot-kraM 4.1±7.2 1.2±5.7 9.0±5.4 5.3±7.41

1 3 1 5

lanoitnevnoC 9.1±2.4 3.1±1.6 3.2±3.8 0.3±7.81

3 4 5 21

mc56-03 evaeL-ot-kraM 8.3±8.01 2.6±6.13 8.4±7.32 9.7±1.66

4 11 9 42

lanoitnevnoC 1.2±4.4 3.4±4.82 8.3±3.42 5.7±1.75

3 81 51 63

mc56> evaeL-ot-kraM 5.7±9.11 1.52±4.511 2.02±0.96 4.83±3.691

4 24 52 17

lanoitnevnoC 2.3±8.3 4.31±8.13 2.41±6.84 6.41±2.48

2 02 03 25

mc57> evaeL-ot-kraM 5.5±9.5 4.22±5.59 4.02±2.26 7.23±5.361

2 43 32 95

lanoitnevnoC 2.3±4.3 0.11±4.32 7.21±8.43 0.31±6.16

2 51 22 93

latoT evaeL-ot-kraM 8.7±4.52 3.72±5.451 6.12±2.79 7.24±0.772

9 65 53 001

lanoitnevnoC 5.4±4.21 9.31±3.66 8.61±2.18 9.71±9.951

8 24 05 001

ecnereffiD 0.9±0.31 7.03±2.88 4.72±0.61 3.64±2.711

eulav-p 1461.0 1900.0 4465.0 4910.0a seulav-p naroftnereffidyltnacifingiseraecafdlobcilatini α gnitsetdedulcerpeziselpmaS.rehgihylbaecitoneraepytecafdlobnismetI.1.0=

.secnereffidtnacifingisrof

26 Mike Richardson, General Foreman, Weyerhaeuser’s North Island Timber-lands Division; personal communication, summer 2001.

30



Tabl

e 29

. Den

sity

of “

pote

ntia

l” lo

gs in

sta

ndin

g tr

ees

(Tre

e C

lass

cat

egor

y A

+B

+D

and

und

ersi

zed

tree

s), b

y lo

g gr

ade

and

stud

y bl

ock

(mea

n ±

SE

). a

kcolbydutS

retemai

Dssalc

htgneL

ssalc

yrogetacro

edarG

goL

latoT)ah/seceip.on(

J+I+H

)ah/seceip.on(U+

X)ah/seceip.on(

Y(≥≥ ≥≥≥

)dnuos%08

)ah/seceip.on(

Y)dnuos

%08<()ah/seceip.on(

Y)ah/seceip.on(

Z)ah/seceip.on(

Z+Y

)ah/seceip.on(spot

&sp

mutS)ah/seceip.on(

evaeL-ot-kra

Mmc

03<≤

m3

0.0±

0.07.3

±8.11

9.8±

8.150.0

±0.0

9.8±

8.150.0

±0.0

9.8±

8.150.0

±0.0

5.01±

6.36

m01-1.3

8.5±

6.311.02

±9.511

2.4±

7.226.3

±1.9

0.4±

8.130.0

±0.0

0.4±

8.130.0

±0.0

7.42±

4.161

m01>

9.0±

9.09.0

±9.0

9.0±

9.00.0

±0.0

9.0±

9.00.0

±0.0

9.0±

9.00.0

±0.0

5.2±

7.2

latoT6.5

±6.41

4.12±

6.8218.8

±5.57

6.3±

1.95.01

±6.48

0.0±

0.05.01

±6.48

0.0±

0.01.33

±7.722

mc56-03

≤m

30.0

±0.0

1.2±

3.25.5

±8.12

0.0±

0.05.5

±8.12

0.0±

0.05.5

±8.12

0.0±

0.03.7

±1.42

m01-1.3

2.6±

2.332.8

±7.74

5.7±

7.220.4

±6.31

0.8±

4.636.2

±0.5

6.8±

4.140.0

±0.0

8.61±

3.221

m01>

9.31±

0.0019.3

±6.41

6.3±

6.411.2

±3.2

0.4±

8.610.0

±0.0

0.4±

8.610.0

±0.0

7.41±

4.131

latoT9.51

±2.331

7.01±

6.468.01

±1.95

9.3±

9.515.11

±0.57

6.2±

0.50.21

±0.08

0.0±

0.06.52

±7.772

mc56>

≤m

30.0

±0.0

1.1±

8.18.1

±7.2

0.0±

0.08.1

±7.2

9.0±

9.06.2

±6.3

0.0±

0.04.3

±5.5

m01-1.3

4.4±

4.623.1

±7.2

0.0±

0.07.2

±1.9

7.2±

1.99.1

±6.4

6.3±

6.310.0

±0.0

8.5±

7.24

m01>

6.6±

7.258.2

±2.8

7.3±

1.90.6

±2.81

5.7±

3.721.1

±8.1

2.7±

1.920.0

±0.0

3.01±

0.09

latoT8.7

±1.97

6.3±

7.219.3

±8.11

6.5±

3.727.7

±1.93

8.2±

3.74.8

±4.64

0.0±

0.07.31

±2.831

spot&

spmutS

0.0±

0.00.0

±0.0

0.0±

0.00.0

±0.0

0.0±

0.00.0

±0.0

0.0±

0.08.94

±3.764

8.94±

3.764

latoT3≤

m0.0

±0.0

8.5±

9.511.11

±4.67

0.0±

0.01.11

±4.67

9.0±

9.00.11

±3.77

0.0±

0.04.51

±2.39

m01-1.3

9.9±

2.376.91

±4.661

0.9±

5.541.3

±8.13

1.9±

3.771.3

±6.9

1.9±

8.680.0

±0.0

7.42±

4.623

m01>

6.41±

6.3518.3

±6.32

8.4±

6.421.6

±5.02

9.7±

0.541.1

±8.1

6.7±

8.640.0

±0.0

2.02±

1.422

spot&

spmutS

0.0±

0.00.0

±0.0

0.0±

0.00.0

±0.0

0.0±

0.00.0

±0.0

0.0±

0.08.94

±3.764

8.94±

3.764

latoT5.91

±8.622

3.12±

9.5026.41

±4.641

2.6±

3.256.81

±6.891

8.3±

3.212.81

±9.012

8.94±

3.7646.09

±9.0111

lanoitnevnoC

mc03<

≤m

30.0

±0.0

7.31±

5.246.01

±0.05

6.1±

7.18.01

±7.15

0.0±

0.08.01

±7.15

0.0±

0.08.22

±2.49

m01-1.3

4.9±

1.725.61

±0.011

5.6±

7.630.2

±1.2

1.6±

8.830.0

±0.0

1.6±

8.830.0

±0.0

9.81±

8.571

m01>

1.2±

8.31.2

±9.2

0.0±

0.07.1

±5.2

7.1±

5.20.0

±0.0

7.1±

5.20.0

±0.0

7.3±

2.9

latoT0.01

±8.03

0.52±

4.5514.11

±7.68

7.2±

3.66.21

±9.29

0.0±

0.06.21

±9.29

0.0±

0.02.83

±2.972

mc56-03

≤m

30.0

±0.0

1.2±

9.23.3

±3.31

0.0±

0.03.3

±3.31

1.2±

9.20.3

±3.61

0.0±

0.03.4

±2.91

m01-1.3

5.11±

5.266.6

±6.45

6.6±

1.731.2

±6.4

8.6±

7.148.0

±8.0

9.6±

5.240.0

±0.0

2.81±

6.951

m01>

1.8±

8.866.5

±8.81

3.5±

8.518.2

±9.7

3.5±

8.320.0

±0.0

3.5±

8.320.0

±0.0

9.9±

3.111

latoT8.21

±3.13

5.8±

3.675.9

±3.66

4.3±

5.213.8

±8.87

4.2±

8.38.7

±5.28

0.0±

0.08.91

±0.092

mc56>

≤m

30.0

±0.0

1.1±

7.11.1

±7.1

0.0±

0.01.1

±7.1

8.0±

8.02.1

±5.2

0.0±

0.08.1

±2.4

m01-1.3

7.5±

5.728.1

±0.5

1.1±

7.15.2

±8.5

6.2±

5.78.2

±3.8

6.3±

8.510.0

±0.0

0.6±

3.84

m01>

1.8±

5.758.1

±0.5

2.1±

5.29.4

±5.72

8.4±

0.038.0

±8.0

9.4±

8.030.0

±0.0

0.21±

3.39

latoT3.9

±0.58

5.3±

7.112.2

±8.5

2.6±

3.335.6

±2.93

1.3±

0.016.5

±2.94

0.0±

0.00.21

±8.541

spot&

spmutS

0.0±

0.00.0

±0.0

0.0±

0.00.0

±0.0

0.0±

0.00.0

±0.0

0.0±

0.04.06

±3.625

4.06±

3.625

latoT≤

m3

0.0±

0.07.31

±1.74

3.11±

0.566.1

±7.1

5.11±

7.661.2

±8.3

5.21±

4.070.0

±0.0

0.42±

5.711

m01-1.3

9.41±

1.7113.71

±6.961

2.01±

4.578.2

±5.21

4.01±

9.787.2

±2.9

0.9±

1.790.0

±0.0

1.13±

8.383

m01>

0.31±

0.0311.7

±7.62

3.5±

3.810.5

±9.73

9.8±

3.658.0

±8.0

9.8±

1.750.0

±0.0

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8.312

spot&

spmutS

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±0.0

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a.

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31


Technical Report TR-017 March 2002 Research Section, Vancouver Forest Region, BCMOFTa

ble

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8.32

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2.423.4

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7.99

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9.691

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0.08.4

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9.637

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32



tors influence not only the number of pre-harvest CWD pieces,but also the number of the timber-derived logs in Grades Y+Zcombined that are retained, intact, in the setting following harvest.

Whether the pre-harvest CWD pieces are left intact dependson such factors as merchantability, harvesting method, and stateof decay. Except in the case of safety, merchantable CWDpieces are generally utilized to avoid billing. The relative propor-tion of merchantable to non-merchantable wood is governed bysite factors, such as stand age, edatopic conditions, and localmortality agents. For the pilot site, the majority of the CWDpieces were low-value (Y Grade) or non-merchantable (Z Grade),and ranged from Moderately Decayed to Well Decayed. The lit-erature reports breakage and crushing as a major harvesting-related hazard for these softer, decomposed pieces (McCarthyand Bailey 1993; Gore and Patterson 1985; Davis et al. 2001).Moderately Decayed to Well Decayed pieces were often brokenup or crushed due to falling trees; machine traffic; yarding (i.e.,picking-up and dropping of pieces that appear to be merchant-able); or dragging pieces when yarding deflection was low.

Similarly, various factors influence how many of the potentiallow-value/non-merchantable pieces (Y+Z) in the standing tim-ber are retained in the setting. The pulp market is a majorinfluencing factor in terms of the utilization of low-grade woodin the timber, e.g., Y Grade logs. On the pilot site, the Y Gradelogs in the timber represented approximately 18% of the totalcruise value. In low market conditions, such as in 2000/2001,Y Grade logs will be left in the setting; however, these logs willlikely be utilized with improved market conditions. Other fac-tors that determine how many low-value/non-merchantablelogs are yarded to roadside or loaded off site include:

� species susceptibility to shattering (e.g., western redcedar)� shattering will affect the dimensions, not only of the re-coverable wood, but also of the non-merchantable wood(Ruth and Harris 1975);

� inability to visually assess merchantability until the log isyarded to roadside;

� concern that the operation will be penalized for leavingmerchantable logs on the setting; bucking to preferred loglengths; or lack of training (Phillips 2001).

Many of the latter risk factors can be minimized, but not elimi-nated, by the modified bucking and yarding practices used inthe Mark-to-Leave Block. Comparing the two blocks will pro-vide an opportunity to evaluate the effects of the two buckingand yarding practices on volume and piece dimensions, andwill serve to highlight difficulties in implementing these prac-tices on an operational scale.

8.2 Block Comparisons

The total gross volumes of low-value and non-merchantablewood in the timber and CWD combined were not significantlydifferent between the two blocks. However, there were a fewsignificant differences between the blocks in the distributionof this wood, which may or may not confound the detectionof post-harvest differences. The high within-block variabilityof most, although not all, compiled strata, undoubtedly ob-scured the detection of other differences between blocks.

The main significant difference detected between the blocks isthe total CWD volume/ha. The significantly higher total CWDvolume/ha for the Mark-to-Leave Block reflects a noticeablyhigher density of larger sized pieces. In addition, there is asignificant difference in the distribution of pieces by decayclass between the blocks. The Conventional Block has a higherproportion of smaller pieces in the Well-Decayed Classes, whilethe Mark-to-Leave Block has a higher proportion of largerpieces in the Moderately to Well-Decayed Classes.

Because CWD represents approximately one-third of the total�potential� low-value/non-merchantable wood volume on site,the effect of these differences on the retention of CWD afterharvest is unclear. If the large CWD pieces are displaced and/or crushed during harvesting (i.e., do not contribute to thepost-harvest CWD), then the pre-harvest differences can beignored when making post-harvest comparisons. On the otherhand, if the large CWD pieces are undisturbed, then the pre-harvest differences will account for a greater or lesser propor-tion of the post-harvest differences, depending on whetherthe input of low-value logs from the standing timber is large orsmall. In any event, the pre-harvest differences will be accountedfor in part by comparing the change in total �potential� low-value/non-merchantable wood after harvesting for both blocks.The large pieces are of particular importance because there isan influx of small-diameter pieces and a possible loss of largerpieces after harvesting (McCarthy and Bailey 1993; Pong andHenley 1973; Gore and Patterson 1985).

8.3 Literature Comparisons for Dead Wood

8.3.1 Total Volume/ha

Total CWD volumes reported in the literature for the CWHvmsubzone variants, or related ecosystems, vary. Table 32 pro-vides examples from the sparse literature. Research by Spies etal. (1988) in the Cascade Mountains in Washington State isincluded, even though Douglas-fir is the dominant species inthese stands, because these forests have ages that are compa-rable to many stands in the CWHvm subzone variant (i.e., >350

kcolBydutS ytisneD)ah/seceip.on(

emuloVm( 3 )ah/

evaeL-ot-kraM 2.7±1.92 4.65±4.702

lanoitnevnoC 9.4±8.03 8.53±5.152

ecnereffiD 8.51±3.3- 2.801±0.62-

eulav-p 4538.0 7218.0

Table 31. Potential large low-value/non-merchantable pieces(diameter >65 cm; length >10 m) in Tree Classes A, B, and D:differences in density and volume, by study block (mean ± SE).

33



years), and because Douglas-fir, like western redcedar and cy-press, are decay resistant. [It is noted that comparisons be-tween different inventories must be done cautiously becauseof differences in definitions: e.g., decay classification, mini-mum diameter, volume functions, and sampling methods(Fridman and Walheim 2000).]

The total pre-harvest volume/ha of CWD (216 m3/ha) in thisstudy is noticeably less than several values reported in the lit-erature for old-growth stands in the CWHvm subzone variant,but is within the general range reported by Inselberg (1993)and by Beese and Toms (1995). It is anticipated that the ob-served between-study variation in total CWD volume reflectsstand-to-stand differences in such factors as:

1. Species composition: Stand composition influences the sizeof dead-wood pieces because species differ in longevity andmaximum potential size (i.e., diameter and height) (Franklin

and Warring 1980). Further, species differ in their suscepti-bility to decay. Western redcedar, cypress, and Douglas-firare decay resistant, therefore CWD may persist for centu-ries. In contrast, species such as western hemlock and bal-sam are more susceptible to decay (Graham 1982, as citedon page 1701 in Spies et al. 1988). Spies et al. (1988) sur-mise that stands dominated by western hemlock tend tohave lower peak total dead wood biomass levels in an old-growth stage than will stands dominated by Douglas-fir inan old-growth stage.

2. Site productivity: The growing potential of a site, i.e., soilmoisture and/or nutrient regimes, directly influences thesize of live trees and indirectly influences the size and vol-ume of dead wood (Ruth and Harris 1975). Harmon et al.(1986) refer to this positive relationship between total deadwood production and living biomass (cited on page 605 inHarmon and Chen 1991). For virgin pine and spruce stands

deticerutaretiL metsysocE setiS).on(

stolP).on(

emuloVseicepS

/noitisopmocytivitcudorp

latotnaeMDWC

m( 3 )ah/

latotnaeMsgans

m( 3 )ah/

latotnaeMdoowdaed

m( 3 )ah/

6991smoTdnaeseeB 1mvHWC 2 1 745ot241 ylnoah/smetS .a.n wHwC

6991smoTdnaeseeB 2mvHWC 2 1 944ot551 ylnoah/smetS .a.n aBwHwC

7991womyforTdnaslleW mvHWC 4 1 121±056 .a.n .a.n

3991greblesnI 1mvHWC ylnoah/smetS .a.n .a.n

ytivitcudorpwoL 8 1 58~ a

ytivitcudorp.deM 11 1 024~

ytivitcudorphgiH 51 1 053~

3991greblesnI 2mvHWC ylnoah/smetS .a.n .a.n

ytivitcudorpwoL 5 1 093~

ytivitcudorp.deM 2 1 062~

0002dragguH mvHWChctaptnanmeR

2 1 007ot096~ ylnoah/smetS .a.n dFwHwC

8991.lateseipS /kcolmehnretseW:senozrifrevliscificaP

sedacsaCnotgnihsaW

42 5 32±913 52±722 63±445 wHdF

a .shpargmorfsetamitsE

Table 32. Examples of total, old-growth, dead-wood volumes reported in the literature.

34



in Sweden, Linder et al. ( 1997) report a strong relationshipbetween total stem volume (live and dead trees) and siteproductivity (m3/ha/y). However, they found no detectablerelationship between the volume of dead trees (standingand fallen) and site quality. In old-growth Coastal DouglasFir stands in the United States, Spies et al. (1988) report apositive relationship between total dead-wood volume andmoisture class. For old-growth stands in the Coastal WesternHemlock biogeoclimatic zone of British Columbia, Inselberg(1993) also reports a positive relationship between total CWDvolume and medium-to-high site productivity (i.e., soil mois-ture/nutrient regimes).

3. Succession stage: For a given subzone variant, the durationof the old-growth successional stage can vary, thus reflect-ing the above factors and local disturbance agents. Researchsuggests that the older stands will tend to have the highertotal dead-wood volumes (Spies et al. 1988; Wells et al. 1988).Based on models for Douglas-fir stands, total dead woodaccumulates well into late succession until perhaps a steadystate is reached 1200�1500 years after stand establishment.Spies et al. (1988) indicate that a steady state would prob-ably not be achieved if a major disturbance occurred. Inthe CWHvm2 subzone variant, the projected return inter-val for catastrophic disturbances is >250 years (BCMOF1995). However, ages for some individual trees for thissubzone variant are reported to be well beyond 450 years(Beese and Toms 1995).

4. Dominant mortality agent (e.g., wind versus insects): The inten-sity and frequency of local mortality agents influences boththe size and density of dead trees, and whether these treesare standing or down.

Collectively, the above factors govern total dead-wood volumeand its associated attributes, as well as the proportion of deadwood that is on the ground. As a result, it is not surprising thata poor relationship exists between standing or suspended anddown material (Harmon and Sexton 1996). Harmon and Sex-ton state that �even within a single forest type, it is not unusualto find that this proportion varies widely; snags can make up aslittle as 2% or as much as 98% of the dead wood biomass�.For old-growth stands in Sweden, Fridman and Walheim (2000)report a wide range in the ratio of snag-to-CWD volumes acrosssix vegetation zones. In the absence of a large data set, totaldead-wood volume may be a more stable index for interpreta-tion than CWD alone.

In this study, the total dead-wood volumes in the blocks werenot significantly different, representing 23 to 29% of the totalsite volume. However, the total CWD volumes in the blockswere significantly different.

8.3.2 CWD Piece Attributes

Much of the available information about the attributes of CWDfor comparable ecosystems is limited to volume/ha by diam-eter class or decay class. More recent research on CWD at-tributes in other ecosystems has started to focus on other at-tributes such as piece density and length (e.g., Torgersen and

Bull 1995) and percent cover (e.g., Carey and Johnson 1995).This extra information provides key habitat information for arange of species, for instance, black bears (Davis 1996), pileatedwoodpeckers (Hartwig 1999), and carpenter ants (Torgersen andBull 1995). This additional information is also required for com-parisons to various American federal CWD guidelines which referto number of pieces/ha by diameter and length classes (PNW1995; USDA 1994). Studies that document this informationhave, to date, been conducted in only the drier ecosystems.

In this study, the large-diameter pieces represent a small pro-portion of the total number of CWD pieces (~10%), but rep-resent a large portion of the total CWD volume (~60%). Forlogs with a large-end diameter >60 cm, Spies et al. (1988) re-port a mean density of 66 pieces/ha. In the Mark-to-LeaveBlock, the mean density for CWD pieces with a large-end di-ameter >65 cm is 66 pieces/ha; 32 pieces/ha have a piecelength >10 m. Wells and Trofymow (1997) report logs with atransect diameter >60 cm represent over 50% of the totalCWD volume/ha for old-growth stands in the CWHvm subzonevariant. Large pieces are of particular importance for CWDmanagement because these are the pieces at most risk for re-moval or break-up during harvesting. Typically, harvesting re-sults in an increase in the smaller pieces, due in part to utiliza-tion size limits, e.g., 3-m logs and 10-cm tops (Davis et al. 2001;Ruth and Harris 1975; Spies et al. 1988).

In this study, the majority of CWD volume/ha is split equallybetween the Moderate and High Decay Classes. For old-growthstands, Spies et al. (1988) and Wells and Trofymow (1997)similarly report most of the CWD volume/ha in Decay Classes3 and greater. The relative proportions between the Moder-ately Decayed and Well-Decayed Classes vary slightly, but inboth these studies the higher decay classes (Decay Classes 4and 5) represent over 30% of the total volume. Differences involume distribution by decay class likely reflect differences inthe decay rates of different species.

8.4 Post-Harvest Surveys

Upon completion of the primary harvesting (e.g., early June2001), the two blocks will be inspected to determine whetherthe distribution of CWD is relatively uniform throughout theharvesting site stratum. Based on a preliminary walk-though inNovember 2000, it is anticipated that five strata will be sampled:

1. Roadside: 15-m width on either side of road.

2. Fall-out zone: 10 m adjacent to the roadside stratum onthe down-slope side of the road.

3. Knoll shadow: on the Mark-to-Leave Block.

4. Debris piles in the excavator-forwarded areas.

5. Remainder of the dispersed stratum.

Plots that were sampled prior to harvesting will be re-estab-lished, classified as to strata, and sampled. Additional plots, ora minimum of three plots per new stratum, whichever is larger,will be established to provide representation by area.

35



8.5 Towards the Development of QuantitativeCWD Management Guidelines: Future Survey Needs

In addition to providing a comparison between bucking andyarding practices, an underlying objective of this study was tocontribute stand-level information to a database that will beused to evaluate the need for establishing targets for CWDretention. The study provides intensive pre- and post-harvestdata for an old-growth stand in the CWHvm2 subzone variantwith high decay and waste.

A full pre-harvest inventory, such as used in this study, pro-vides an opportunity to relate one ecosystem component toanother (Harmon and Sexton 1996). A variety of current andhypothetical questions can therefore be posed.

1. What proportion of the total stand volume is representedby dead wood?

2. What proportion of the total dead wood is down?

3. What proportions of the total stand volume or total dead-wood volume are represented by proposed CWD targets?

4. What are the dimensions of a large CWD piece?

5. What is the density of a large CWD piece?

6. Are the diameters of live and dead stems sufficientlylarge to provide for large CWD pieces?

The timber net factoring call grading27 included in this studyalso permits exploration of merchantability questions such as:

1. What is the total, �potential�, low-value wood availableon site, i.e., in terms of CWD, standing timber?

2. How much of the original CWD is merchantable?

3. Is there sufficient �potential� low-value/non-merchant-able wood to meet proposed CWD targets? If not, what arethe management strategies?

The post-harvest inventory permits an evaluation of such ques-tions as:

1. Under different harvesting systems (e.g., clearcut, vari-able retention, single-tree selection):

� What proportion of the total, �potential�, low-value/non-merchantable wood was retained as CWD or stand-ing trees in the setting, at roadside, and in reserves?

� What are the dimensions of the CWD pieces retainedin the setting, at roadside, and in reserves?

� How much of the pre-harvest CWD was left intact inthe setting, roadside, and reserves?

2. What proportion of the post-harvest CWD volume isbenchmark?

3. What is the ratio of post-harvest CWD to pre-harvesttotal dead wood volume/ha?

This study was designed to address a broad range of questions.Detailed projects, such as this study, which involve intensivepre- and post-harvest monitoring of different options for man-aging CWD, are expensive and time consuming. However, alimited number of these types of projects are required to inte-grate issues related to forestry, economics, ecology, and opera-tions. The integrated study provides baseline data, but moreimportantly it provides the data required to �troubleshoot�potential management issues during the developmental ratherthan the implementation stage of CWD management guide-lines: i.e., do the proposed target volumes exceed the total low-value/non-merchantable wood volumes; which operationaltools are cost-effective and where?

The intensive project, however, is too costly and time consum-ing to provide the broad database required for developing tar-gets for CWD management. A more cost-effective approachof collecting stand data over a broad range of sites, and withina relatively short time frame, is required to establish a suffi-ciently large database. Current operational surveys (i.e., resi-due survey, operational cruise) provide only a portion of therequired stand data. Research data, while often complete, arelimited in scope. The alternative to collecting data through anindependent survey, which will be costly, is to append the col-lection of the �missing� CWD data to an existing operationalsurvey. Because CWD attributes are closely tied to those ofstanding live and dead trees, and there is some overlap in datacollection, e.g., windfalls, the logical choice is to collect the re-quired CWD measurements at the time of the operational cruise.This �modified� operational cruise might apply to all or only asubset of the total plots. The feasibility of this approach iscurrently under investigation by members of the VancouverForest Region�s CWD Working Group (TWIFPPSC 2001).

For Coastal old-growth stands, in particular, it will be advanta-geous for the operational cruise to include net factoring callgrading because: 1) low-value/non-merchantable wood ispresent in both live and dead trees, and 2) net factoring callgrading generally provides a more accurate estimate of mer-chantability and log dimensions than the BCMOF�s appraisalcruising procedures28. In the short-term, the operational cruiseshould provide an inventory of all dead trees and CWD vol-umes and attributes. Until the database is sufficiently large, �totaldead wood� may be a useful management index of dead wood,owing to the variable nature of CWD alone.

Any future database will require stratification by factors thatinfluence dead-wood attributes. Preliminary summary strata mayinclude: stand age (e.g., young, mature, old-growth), natural dis-turbance regime, dominant species, and site productivity group-27 Call grading and net factoring are processes used to assess timber quality

and net tree volume. They are applied to the tree as the cruiser sees it. Noattempt is made to predict grade based on falling breakage or any manufactur-ing process, or to predict volume loss without direct evidence (e.g., VegetationResources Inventory). 28 See Footnote 6.

36



ings (e.g., L and M+H based on the BC Ministry of Forest�sSite Index Estimates by Site Series for Coniferous Tree Species in BritishColumbia (BCMOF 1997)). An approach such as this will re-duce the total number of strata by groupings that can be re-lated back to biogeoclimatic classification, i.e., subzone vari-ants, moisture groupings. Table 33 is an example of a pre-harvest site summary table; Table 34 is an example of a pre-harvest CWD summary table. Table 35 is an example of apost-harvest CWD summary table for the dispersed stratum.Similar summaries for other post-harvest strata (e.g., roadside,piles) will also be of interest. Once the database is sufficientlylarge, however, analyses such as misclassification matrix, discrimi-nate or cluster analyses should be used to evaluate the efficacyof the original and to suggest alternative summary strata.

Last, the future development of quantitative CWD manage-ment guidelines will require the integration of multiple sourcesof information, e.g., landscape management objectives, wild-life habitat research, operational issues, stand development mod-els. The availability of a database that provides pre- and post-harvest information on all main stand structures and strata(e.g., roadside, Wildlife Tree Patches), will be valuable to thedevelopmental process, as it will provide insight into the impli-cations (i.e., economic, ecological) of future retention targets,and provide data to evaluate options for integrating, on a quan-titative basis, CWD objectives with those for Wildlife TreePatches and other reserves (e.g., Riparian Management Zones).

37



ble

33. T

otal

pre

-har

vest

dea

d-w

ood

volu

me,

par

titio

ned

by s

truc

ture

s (s

) and

mer

chan

tabi

lity:

Exa

mpl

e C

oast

al S

umm

ary

Tabl

e (m

ean,

SE

, n).

dnaT

DN

egadaorb

sgnipuorg

daorB

rebmit

sepytytivitcudor

Pssalc

gnidnopserroC

citamilcoegoib

/stnairav

enozbustneirtun

/erutsio

msgnipuorg

dnatslatoT

emulov

a

m(3

)ah/

latoTdoo

w-daede

mulovb

m(3

)ah/

DW

ClatoT

emulov m(

3)ah/

daedlatoT

gnidnatsm(

3)ah/

pmuts

latoTe

mulovc

m(3

)ah/

etislatoT

foe

mulovdoo

wZ+

Ym(

3)ah/

foe

muloV

doow

Z+Y

seertevil

ni)

Assal

Ceer

T(m(

3)ah/

foe

muloV

doow

Z+Y

daedni

seertgnidnats

sessalC

eerT(

)D+

B m(3

)ah/

foe

muloV

doow

Z+Y

DW

Cni

eerT

+rehto(

)E+

Csessal

Cm(

3)ah/

htworg

dlO ro

htworg

dnoces

dFM

+H

30,10m

mFD

C,.g.e

L

wHdF

M+

H LlPdF

M+

H Ly

C/w

CM

+H L

dFw

CM

+H L

1T

DN ro

2T

DN

Sw

CL

+H L

wH

wC

M+

H Lw

HM+

H Lw

Cw

HM+

H LdF

wH

M+H L

aB

wH

M+H L

lPw

HM+

H LlP

M+

H Lc

YlPM

+H L

SM

+H L

mHS

M+

H L

kcolB

evaeL-ot-kra

Mmorf

ELP

MA

XE

htwor

Gdl

Oa

Bw

HF3

D601A

Unae

m10

2mv

HW

C4331

643612

50152

995962

79012

1T

DN

)stolp32(

ES1=

N18

4352

613

74

9251

52

a.sp

mutsdna,

DW

C,gnidnatsdaed

dnaevil

sedulcnie

mulovdnats

latoTb

dna,)"rehto"dna

E+C

sessalC

eerT(

DW

C,)potdna,p

muts,elob(seert

daedgnidnats

sedulcnie

mulovdoo

w-daedlatoT

.)thgiehni

m3<

sganstrohs(

spmuts

c.thgieh

nim

3<gans

daedtrohs

aot

sreferp

mutS

38



Tabl

e 34

. Pre

-har

vest

attr

ibut

es a

nd p

oten

tial s

ourc

es o

f lar

ge C

WD

( ot

her +

Tre

e C

lass

es C

+E

): E

xam

ple

Coa

stal

Sum

mar

y Ta

ble

(mea

n, S

E, n

).

dnaT

DN

egadaorb

sgnipuorg

daorB

rebmit

sepytytivitcudor

Pssalc

gnidnopserroC

citamilcoegoib

/stnairav

enozbustneirtun/

erutsiom

sgnipuorg

dne-egraL

fo.maid

DW

Cegral

seceipa )

mc(

fohtgne

LD

WC

egralseceipa

)m(

latoTfo

ytisnedtsevrah-erp

DW

Cegral

seceipb )ah/.on(

latoTfo

emulov

tsevrah-erpW

Cegral

Dseceipb

m(3

)ah/

latoTfo

ytisnedsevrah-erpt D

WC

egralseceipb

niZ+

Ysedar

G)ah/.on(

latoTfo

emulov

tsevrah-erpD

WC

egralseceipb

niZ+

Ysedar

Gm(

3)ah/

foytisnedlatoT

edarG

Z+Y

egralseceipb

nireb

mitgnidnats

sessalC

eerT()

D+B+

A)ah/.on(

foe

mulovlatoTedar

GZ+

Yegral

seceipb

nireb

mitgnidnats

sessalC

eerT()

D+B+

A m(3

)ah/ht

worgdl

O roht

worgdnoces

dFM

+H

30,10m

mFD

C,.g.e

L

wHdF

M+

H LlPdF

M+

H Ly

C/w

CM

+H L

dFw

CM

+H L

1T

DN ro

2T

DN

Sw

CL

+H L

wH

wC

M+

H Lw

HM+

H Lw

Cw

HM+

H LdF

wH

M+H L

aB

wH

M+H L

lPw

HM+

H LlP

M+

H Lc

YlPM

+H L

SM

+H L

mHS

M+

H L

kcolB

evaeL-ot-kra

Mmorf

ELP

MA

XE

htwor

Gdl

Oa

Bw

HF3

D601A

Unae

m10

2mv

HW

C56

c01

c22

9912

4903

032

1T

DN

)stolp32(

ES1=

Nan

an3

81

37

14

23

a.ycneuqerf

noitubirtsidevitalu

mucrete

maiddna

htgneleht

fo%01

ro5

reppueht

sadenife

Db

.airetirchtgnel

dnarete

maidegral

ehthtob

gniteem

seceipll

Ac

.)7.0(12

fo)

m(htgnel

naem

adna

)6.2(88

fo)

mc(rete

maiddne-egral

naem

aevah

seceipegral

rofairetirc

ehtdeecxe

tahtseceip

DW

C,ydutstnerruc

ehtnI

39



ble

35. P

ost-

harv

est C

WD

attr

ibut

es fo

r the

dis

pers

ed s

trat

um: E

xam

ple

Coa

stal

Sum

mar

y Ta

ble

(mea

n, S

E, n

).

dnaT

DN

egadaorb

sgnipuorg

daorB

rebmit

sepytytivitcudor

Pssalc

gnidnopserroC

citamilcoegoib

/stnairav

enozbustneirtun

/erutsio

msgnipuorg

dne-egraL

fo.maid

DW

Cegral

seceipa )

mc(

fohtgne

LD

WC

egralseceipa

)m(

latoTD

WC

emulov m(

3)ah/

latoTfo

ytisnedD

WC

egralseceipb )ah/.on(

latoTfo

emulov

egralD

WC

seceipb

m(3

)ah/

latoTetsa

welbadiova

kramhcneb

emulov m(

3)ah/

ytisnedlatoT

egralfo

seceipD

WC

sadessalc

elbadiovaetsa

wb )ah/.on(

emulov

latoTegral

foseceip

DW

Csa

dessalcelbadiova

etsaw

b

m(3

)ah/

naem

fooita

Rtsevrah-erp/

DW

Clatot

naem

tsevrah-tsopD

WC

ah/emulov

htworg

dlO ro

htworg

dnoces

dFM

+H

30,10m

mFD

C,.g.e

L

wHdF

M+

H LlPdF

M+

H Ly

C/w

CM

+H L

dFw

CM

+H L

1T

DN ro

2T

DN

Sw

CL

+H L

wH

wC

M+

H Lw

HM+

H Lw

Cw

HM+

H LdF

wH

M+H L

aB

wH

M+H L

lPw

HM+

H LlP

M+

H Lc

YlPM

+H L

SM

+H L

mHS

M+

H L

aycneuqerf

noitubirtsidevitalu

mucrete

maiddna

htgneleht

fo%01

ro5

reppueht

sadenife

D.

b.airetirc

htgneldna

retemaid

egraleht

htobgnitee

mseceip

llA

40



9 LITERATURE CITED

Angelstam, P. 1997. �Landscape Analysis as a Tool for theScientific Management of Biodiversity� in Ecology Bulletin46:140-170.

BC Ministry of Forests. 1997. Ministry Policy Manual. Volume1, Resource Management. Chapter 8, Tenure Administration.Policy 8.1, Timber Utilization�Coastal and Interior. ResourceTenures and Engineering Branch. Victoria, BC.

BC Ministry of Forests. 1999. Scaling Manual. RevenueBranch. Victoria, BC.

��. 2000a. Logging Residue and Waste Procedures Manual.Revenue Branch. Victoria, BC.

��. 2000b. Cruising Manual. Revenue Branch. Victoria,BC.

��. 2000c. Vegetation Resources Inventory��GroundSampling Procedures. Resources Inventory Branch. Victoria,BC. 313p.

��. 2000d. A Short-Term Strategy for Coarse Woody DebrisManagement in British Columbia�s Forests, March 2000.Victoria, BC.

BC Ministry of Forests and BC Ministry of Environment,Lands and Parks. 1995. Biodiversity Guidebook. September1995. Forest Practices Branch, BC Ministry of Forests.Victoria, BC. Forest Practices Code of British ColumbiaGuidebook. 99p.

��. 1996. Forest Practices Code Timber Supply Analysis.Forest Practices Branch, BC Ministry of Forests. Victoria,BC. 33p.

��. 1999. Landscape Unit Planning Guide. Forest PracticesBranch, BC Ministry of Forests. Victoria, BC. ForestPractices Code of British Columbia Guidebook. 101p.

Beese, W.J. and J. Toms. 1995. Age Structure and StandDynamics of Old-Growth Forests on Vancouver Island. Internalreport prepared for Land Use Planning Advisory Team,Corporate Forestry, MacMillan Bloedel Limited. Nanaimo,BC. 34 p.

Bull, E.L. and R.S. Holthausen. 1993. �Habitat Use andManagement of Pileated Woodpeckers in NortheasternOregon� in Journal of Wildlife Management 57(2):335�345.

Bull, E.L.; C.G. Parks; and T.R. Torgersen. 1997. Trees andLogs Important to Wildlife in the Interior Columbia River Basin.Pacific Northwest Research Station, Forest Service,USDA. General Technical Report 391. 55p.

Carey, A.B.; C. Elliott; B.R. Lippke; J. Sessions; C.J.Chambers; C.D. Oliver; J. F. Franklin; and M.G. Raphael.1996. Washington Forest Landscape Management Project: APragmatic Ecological Approach to Small-Landscape Management.Washington State Department of Natural Resources; andPacific Northwest Research Station, Forest Service,USDA. Washington Forest Landscape Management ProjectReport No. 2.

Carey, A.B. and M.L. Johnson. 1995. �Small Mammals inManaged, Naturally Young and Old Growth Forests� inEcological Applications 5(2): 336-352.

Caza, C.L. 1993. Woody Debris in the Forests of British Columbia:A Review of Literature and Current Research. Research Branch,BC Ministry of Forests, Victoria. Land ManagementReport 78. 99p.

Davis, G.; A. Nemec, and E. Redlin. 2001, in preparation.Pre- and Post-Harvest Attributes of Coarse Woody Debris inUnmanaged Forests: Case Studies in Coastal Western HemlockWet Hypermaritime Biogeoclimatic Subzone. Vancouver ForestRegion Forest, BC Ministry of Forests. Nanaimo, BC.Technical Report TR-0xx.

Davis, G.; E. Phillips; and B. Cawley. 2000. Maintaining CoarseWoody Debris in Post-Harvest Settings: Economic and EcologicalImplications of Marking Non-Merchantable Logs after Buckingand Before Yarding�Project Plan. Vancouver Forest RegionForest, BC Ministry of Forests. Nanaimo, BC. Internaldocument. VFR-CWD-00-01.

Davis, H. 1996. Characteristics and Selection of Winter Dens byBlack Bears in Coastal British Columbia. M.Sc. thesis, SimonFraser University. Burnaby, BC. 147p.

Forrester, P.D. 1996. Fibre Recovery from Log Sortyard Residueson Coastal British Columbia. Western Division, FERIC.Vancouver, BC. Technical Note TN-249. 16p.

Franklin, J.F. and R.H. Waring. 1980. �Distinctive Featuresof the Northwestern Coniferous Forest: Development,Structure and Function� pp. 59�85 in Forests: FreshPerspectives from Ecosystem Analysis. Proceedings of the 40th

Annual Biology Colloquium. Oregon State UniversityPress. Corvallis, Oregon.

Fridman, J. and M. Walheim. 2000. �Amount, Structure andDynamics of Dead Wood on Managed Forestland inSweden� in Forest Ecology and Management 131 (1/3): 23�36.

Goodburn, J.M. and C.G. Lorimer. 1998. �Cavity Trees andCoarse Woody Debris in Old-Growth and ManagedNorthern Hardwood Forests in Wisconsin and Michigan�in Canadian Journal Forest Research 28:427�438.

Gore, J.A. and W.A. Patterson III. 1985. �Mass of DownedWood in Northern Hardwood Forests in New Hampshire:Potential Effects of Forest Management� in CanadianJournal Forest Research 16:335�339.

Green, P. and G.F. Peterken. 1997. �Variation in the Amountof Dead Wood in the Woodlands of the Lower Wye Valley,UK in Relation to the Intensity of Management� in ForestEcology and Management 98:229�238.

Hansen, A.J.; T.A. Spies; F.J. Swanson; and J.L. Ohmann.1991. �Conserving Biodiversity in Managed Forests:Lessons from Natural Forests� in BioScience 41(6):382�392.

Harmon, M.E. and H. Chen. 1991. �Coarse Woody DebrisDynamics in Two Old Growth Ecosystems� in Bioscience41(9):604�610.

Harmon, M.E.; J.F. Franklin; F.J. Swanson; P. Sollins; S.V.Gregory; J.D. Lattin; N.H. Anderson; S.P. Cline; N.G.Aumen; J.R. Sedell; G.W. Lienkaemper; K. Cromack Jr.;and K.W. Cummins. 1986. �Ecology of Coarse WoodyDebris in Temperate Ecosystems� in Advances in EcologicalResearch 15:133�302.

41



Harmon, M.E. and J. Sexton. 1996. Guidelines for Measurementsof Woody Detritus in Forest Ecosystems. US LTER NetworkOffice: University of Washington. Seattle, WA. PublicationNo. 20. 73p.

Hartwig, C.L. 1999. Effect of Forest Age, Structural Elements,and Prey Density on the Relative Abundance of PileatedWoodpecker (Dryocopus pileatus abieticola) on South-EasternVancouver Island. M.Sc. thesis, University of Victoria.Victoria, BC. 163p.

Howard, J.O. 1973. Logging Residues � Volume andCharacteristics. Forest Service, USDA. Forest ServiceResource Bulletin PNW-44. (cited in Nagle 1980)

Huggard, D. 2000. Weyerhaeuser BC Variable Retention AdaptiveManagement Program: Habitat Monitoring 1999� Summaryand Sample Design Analysis. Weyerhaeuser, BC CoastalGroup. Nanaimo, BC. Internal document, January 2000.57p.

Inselberg, A.E. 1993. A Survey of the Composition and Structureof Forest Ecosystems in the Tofino Creek Watershed on VancouverIsland. Research Program, BC Ministry of Forests. Victoria,BC. 285p.

Keenan, R. and A. Inselberg. In press. Coarse woody debrisin a forested watershed on the west coast of VancouverIsland, British Columbia.

Kozak, A. 1988. �A Variable-Exponent Taper Equation� inCanadian Journal Forest Research 18:1363�1368.

Per Linder; B. Elfving; and O. Zackrisson. �Stand structureand successional trends in virgin boreal forest reserves inSweden� in Forest Ecology and Management 98(1997):17�33.

Lloyd, R. 2001. A Comparison of Coarse Woody Debris inHarvested and Unharvested Sites in the SBSmc2, First-YearReport. Houston Forest Products Ltd. Houston, BC. 15p.

Maser, C. and J.M. Trappe (editors). 1984. The Seen andUnseen World of the Fallen Tree. Pacific Northwest ResearchStation, Forest Service, USDA. Portland, Oregon. GeneralTechnical Report PNW-GTR-164. 56p.

McCarthy, B. and R. Bailey 1993. �Distribution andAbundance of Coarse Woody Debris in a Managed ForestLandscape of the Central Appalachians� in CanadianJournal Forest Research 24:1317�1329.

Nagle, G.S. 1980. Analysis of Salvage Yarding Systems and Costsin Pacific Coast Forests. ENFOR, Canadian Forestry Service;Dept. of Environment. Ottawa, Ontario. BC-X-214.

Pacific Northwest Research Station. 1995. Decision Notice forthe Revised Continuation of Interim Management DirectionEstablishing Riparian, Ecosystem and Wildlife Standards forTimber Sales. Forest Service, USDA. Portland, Oregon. 13p.(cited in Bull et al. 1997)

Parks, C.G.; E.L. Bull; and T.R. Torgersen. 1997. Field Guidefor the Identification of Snags and Logs in the Interior ColumbiaRiver Basin. Pacific Northwest Research Station, ForestService, USDA. General Technical Report PNW-GTR-390. 40p.

Phillips, E. 2001. A Trial to Determine the Economics of CoarseWoody Debris Retention During Harvesting of Coastal Old-Growth. March 2001�Progress Report. Western Division,FERIC. Vancouver, BC. 16p.

Pong, W.Y. and J.W. Henley. 1978. Characteristics of Residues ina Helicopter Logged Area of Old-Growth Douglas-Fir. PacificNorthwest Forest and Range Experiment Station, ForestService, USDA. Research Note PNW-320. 32p.

Province of British Columbia. Forest Practices Code of BC Act.Operational Planning Regulation (OPR). Part 3�ForestDevelopment Plans. Division 3�Map and InformationRequirements for all Forest Development Plans. Sec 18(1)(u).Victoria, BC.

��. Forest Practices Code of BC Act. Operational PlanningRegulation (OPR). Part 5�Silviculture Prescriptions. Division 1�Scope and Content. Sec 39(3)(m). Victoria, BC.

Reid, C.M.; A. Foggo; and M. Speight. 1996. �Dead Wood inthe Caledonia Pine Forest� in Forestry 69(3): 275�279.

Ruth, R.H and A.S. Harris. 1975. Forest Residues in Hemlock-Spruce Forests of the Pacific Northwest and Alaska�A State-of-Knowledge Review with Recommendations for Residue Management.Forest Service, USDA. Portland, Oregon. GeneralTechnical Report PNW-39. 52p.

Samuelsson, J.; L. Gustafsson; T. Ingelog. 1994. Dying andDead Trees: A Review of Their Importance for Biodiversity.Swedish Threatened Species Unit. Uppsala, Sweden.Swedish Environmental Protection Agency report series,Report 4306.

Site Productivity Working Group (SPWG). 1997. Site IndexEstimates by Site Series for Coniferous Tree Species in BritishColumbia. BC Ministry of Forests and Forest Renewal BC.Victoria, BC. 265p.

Spies, T.A. and S.P. Cline. 1988. �Coarse Woody Debris inForests and Plantations of Coastal Oregon� pp.5�24 inFrom the Forest to the Sea: A Story of Fallen Trees. Technicaleditors C. Maser, R.F. Tarrant, J.M. Trappe, J.F. Franklin.Pacific Northwest Research Station, Forest Service, USDA.Portland, Oregon. General Technical Report PNW-GTR-229. 153p.

Spies, T.A. and J.F. Franklin. 1988. �Old Growth and ForestDynamics in the Douglas-Fir Region of Western Oregonand Washington� in Natural Areas Journal 8(3):190�201.

Spies, T.A.; J.F. Franklin; and T.B. Thomas. 1988. �CoarseWoody Debris in Douglas-Fir Forests of Western Oregonand Washington� in Ecology 69:1689�1702.

Stone, J.N.; A. MacKinnon; and J. Parminter. 1998. �CoarseWoody Debris Decomposition Documented Over 65Years on Southern Vancouver Island� in Canadian Journalof Forest Research 28:788�793.

Timber West/International Forest Products ProjectSubcommittee (TWIFPPSC). 2001. Validation of a ModifiedOperational Cruise Designed to Sample Dead Wood, InterimWorking Document, Version 1. Vancouver Forest Region,BCMOF. Nanaimo, BC.http://www.for.gov.bc.ca/vancouvr/research/cwd/cwdvalidation.pdf

42



Torgersen, T.R. In press. �Characteristics of Log Resourcesin Northeastern Oregon�Case Studies of FourManagement Treatments� pp. xx-xx in Proceedings of Ecologyand Management of Dead Wood in Western Forests, November 2�4 1999, Reno, Nevada. Pacific Southwest Research Station,Forest Service, USDA. Fresno, CA. General TechnicalReport PSW-GTR-xxx-xxx.

Torgersen, T.R. and E.L. Bull. 1995. �Down Logs as Habitatfor Forest-Dwelling Ants�the Primary Prey of PileatedWoodpeckers in Northeastern Oregon� in Northwest Science69 (4): 294�303.

USDA Forest Service; and US Department of the Interior,Bureau of Land Management. 1994. Record of Decision:For amendments to Forest Service and Bureau of LandManagement planning documents within the range of thenorthern spotted owl: Standards and Guidelines: Formanagement of habitat for late-successional and old-growth forest related species within the range of thenorthern spotted owl. [Northwest Forest Plan]. Portland,OR.

Wells, R.W.; K.P. Lertzman; and S.C. Saunders. 1998. �Old-Growth Definitions for the Forests of British Columbia,Canada� in Natural Areas Journal 18:279�292.

Wells, R.W. and J.A. Trofymow. 1997. Coarse Woody Debris onChronosequences in Coastal Forests of British Columbia. PacificForestry Centre, Canadian Forest Service. Victoria, BC.Internal document. 42p.

Wildlife Tree Committee of British Columbia. 1994. Wildlife/Danger Tree Assessor�s Course Workbook. 2nd Edition. EditorsStewart Guy and Todd Manning. Forest ResourcesDevelopment Agreement and BC Ministry of Forests.Victoria, BC.

Wilson, S.M. and A.B. Carey. 2000. �Legacy Retention versusThinning Influences on Small Mammals� in NorthwestScience 74:131�145.

10 GLOSSARY

(BCMOF 2000a, b, c; WTCBC 1994)

Accumulations: Areas where residue and waste are concentrated,e.g., at landings and along roadsides.

Accuracy: Nearness of a measurement to the actual value of thevariable being measured.

Allowed Stump Height: Higher of: 1) contractual stump height, 2)height specified in District Manager letter for heavy snow packs, 3)the minimum distance from the ground on the high side of a stumpup to a point above a physical obstruction which allows for safefalling. Allowed stump height minus contractual stump height =avoidable piece.

Allowable Annual Cut (AAC): Rate of harvest determined by theChief Forester for Timber Supply Areas (TSAs) and Tree Farm Li-censes (TFLs), and by the District Manager for Woodlot Licenses(WLs), and the rate of harvest specified in a licence or in a manage-ment and working plan.

Avoidable Residue or Waste: Residue or waste wood volumes left onthe ground that: a) could have been removed safely, b) were notphysically obstructed, and c) were not inaccessible.

Biogeoclimatic Ecosystem Classification: Hierarchical classifica-tion scheme having three levels of integration: regional, local, andchronological; and combining climatic, vegetation, and site factors.

Biogeoclimatic Zone: A geographic area having similar patterns ofenergy flow, vegetation, and soils as a result of a broadly homoge-neous macro-climate. British Columbia has 14 zones.

Breakage: Any piece meeting the minimum diameter of the cuttingauthority which is shorter than 3.0 m in length and broken at thelarge end or at both ends. Normal breakage is not usually recorded.

Bucking Waste: Any piece less than 3 m in length that has been cutat the large end, or at both ends. It has been cut through improper orcareless bucking practices.

Call Grading: Procedure used to assign one of the Vegetation Re-sources Inventory (VRI) grades (modified coastal log grades) to stand-ing and fallen timber. Grading is a hierarchical process. The gradeextends up the tree as long as the grade rules allow. When a knot orother defect is encountered or the diameter can no longer supportthat grade, the grade changes for the next portion of the tree. (VRI)

Call Grading And Net Factoring: Processes used to assess timberquality and net tree volume. They are applied to the tree as the cruisersees it. No attempt is made to predict grade based on falling breakageor any manufacturing process, or to predict volume loss withoutdirect evidence (e.g., Vegetation Resources Inventory).

Chunk: Short piece of residue or waste that has resulted from endtrimming logs, or from breaking logs during extraction operations.

Coast: Refers to the Vancouver Forest Region and the North CoastForest District of the Prince Rupert Region.

43



Constrained: Part of the timber harvesting landbase subject to con-straints on harvesting due to land use or integrated resource manage-ment objectives (e.g., riparian management areas, terrain sensitive areas,recreation areas, lake shore management areas, ungulate winter range)

Cutblock: A discrete area logged according to the harvesting planand approved for the cutting authority issued under the license.

Cut Control: The Forest Service�s procedures to monitor the vol-umes of timber harvested under a license through scaling and residuesurveys, and the calculation and administration of the volumes remain-ing to be harvested under the license for the Cut Control period.

Cutting Authority: Refers to one of the following: Timber Sale Li-cense, License to Cut, Road Permit, or Cutting Permit issued under aTree Farm License, Forest License, Timber License, or Woodlot License.

Cutting Specifications: Timber cutting specifications contained inthe Minimum Utilization Standards of the cutting authority.

Danger Tree: Any tree that is hazardous to workers because oflocation or lean, physical damage, overhead deterioration of the limbs,stem or root system, or a combination of these.

Dispersed Stratum: In this stratum, residue and waste occur on theareas from which trees or logs have been removed and where sampleplots can safely be established.

High Side (stumps): The position where the ground meets thestump on the uphill side, ignoring any root flare, obstacles, vegeta-tion, and loose matter that have accumulated at the base of the tree.Length measurements usually start from 30 cm above this point.

Net Factoring: Estimating the net volume of sound wood (grossvolume less decay) of variable log lengths. These net volumes arebased on: 1) direct measurements (includes visual estimates andphysical measurements); or 2) standard, rule-based deductions asso-ciated with loss indicators. (VRI)

Pencil Bucking: An imaginary sectioning of trees or CWD intopotential logs. (VRI)

Log Grades: Log grades that are defined in the Scaling Regulation.

Minimum Utilization Standards: Standards of timber cutting andlog utilization specified in the cutting authority.

Natural Disturbance Type (NDT): An area characterized by a naturaldisturbance regime. There are five natural disturbance types identifiedfor managing biological diversity, two of which occur on the Coast.

Old Growth/Old Seral: Forests of a certain age or forests with theappropriate old forest attributes. Old growth and old seral are usedinterchangeably.

Precision: The closeness, to each other, of repeated measures ofthe same quantity, expressed as a sampling error or standard error ofthe sample estimate.

Reserves: Forested patches or individual trees retained during har-vesting, or other forestry operations, to provide habitat, scenic,biodiversity or other values. They are long-term retention areas�

generally one rotation or longer. Trees retained for a shorter term,such as seed or shelterwood trees, are not reserve trees. Reserve cat-egories include: Wildlife Tree Patches from contributing landbase;uniformly distributed Wildlife Trees from contributing landbase;Wildlife Tree Patches from non-contributing landbase; Riparian Re-serve; Gully Reserve; other stand-level reserves.

Residue: The volume of timber left on the harvested area that meetsor exceeds the size requirements but is below the log grade require-ments of the minimum utilization standards specified in the cuttingauthority. Residue volumes that are avoidable or unavoidable aresubject to Cut Control charges.

Roadside Stratum: In this stratum, residue and waste occur alongthe roadsides to which logs have been yarded or skidded.

Sampling Error (SE): A measure of the variation among samplemeans is the standard error of the mean. It can be thought of as astandard deviation among sample means; it is a measure of thevariation among sample means, just as the standard deviation is ameasure of the variation among individuals. When we increase ourconfidence level above one standard deviation i.e., two standard de-viations, we refer to the statistic as the sampling error.

Stratification: The process of delineating strata boundaries withina subpopulation, where each stratum has unique characteristics (tim-ber type, logging contractors, season, or year logged).

Timber Supply Review (TSR): An assessment of how currentforest management practices will affect the supply of wood availablefor harvesting over time. It also assesses how timber supply may beaffected by changes in management practices and uncertainties aboutforest inventory and growth.

Trimming �Waste�: Avoidable waste or residue that results fromtopping, slashing, bucking, and end-trimming in a manner that doesnot maximize utilization under the cutting specifications.

Utilization: Removal of timber from a cutblock in accordance withthe utilization standards specified in the cutting authority.

Utility Grade logs: U and X grade logs.

Utility Grade and better logs: All grades other than Y and Z grade.

Variable Length Call Grading: Recognizes only a minimum lengthand allows the cruiser to pencil buck at grade changes rather than atpredetermined log lengths. (VRI)

Variant: A subdivision of a biogeoclimatic subzone. Variants reflectfurther differences in regional climate and are generally recognized forareas slightly direr, wetter, snowier, warmer, or colder than otherareas in the subzone.

Waste: Volume of timber left on the cutting authority area thatshould have been utilized in accordance with the timber utilizationstandards specified in the cutting authority. Waste volumes are sub-ject to Cut Control charges.

Wildlife Tree or Wildlife Tree Patch: A tree or group of trees identi-fied in an operational plan to provide present or future wildlife habitat.

44



APPENDIX A. DEFINITIONS OF SPECIES-SPECIFIC COASTAL LOG GRADES

Definitions from the provincial Scaling Manual (BCMOF 1999) and the Logging Residue and Waste Measurement Procedures Manual(BCMOF 2000a).

continued

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45



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continued

46



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47



APPENDIX B:

OPERATIONAL TRIAL TO EVALUATE THE USE OFMODIFIED HARVESTING PRACTICES IN COASTAL OLD-GROWTH STANDS TO

MAXIMIZE COARSE WOODY DEBRIS LEVELS:

DESCRIPTIONS OF THE BUCKING, YARDING, AND LOADING PHASES

Prepared byE. Redlin

Azmeth Forest Consultants Ltd.Nanaimo, BC

February 28, 2002

TABLE OF CONTENTS

1.0 INTRODUCTION AND OBJECTIVES...................................................................................................................48

2.0 SITE DESCRIPTION..............................................................................................................................................48

3.0 DESCRIPTION OF METHODS AND PRACTICES................................................................................................48

3.1 FALLING AND BUCKING METHODS..........................................................................................................483.2 MARK TO LEAVE ..........................................................................................................................................503.3 YARDING AND LOADING ............................................................................................................................50

4.0 OBSERVATIONS....................................................................................................................................................50

5.0 REFERENCES........................................................................................................................................................50

APPENDIX B-1 GLOSSARY OF TERMS.....................................................................................................................59

APPENDIX B-2 WEYERHAEUSER’S SPECIFICATIONS CARD FOR FALLERS........................................................60

APPENDIX B-3 EXPLANATION OF RESIDUE AND WASTE BILLING....................................................................61

APPENDIX B-4 WEYERHAEUSER’S GUIDE TO LOG IMPROVEMENT....................................................................62

48



1.0 INTRODUCTION AND OBJECTIVES

In 1999, under the guidance of the Coarse Woody DebrisWorking Group, the Vancouver Forest Region initiated an op-erational study to examine the feasibility of using modifiedbucking and yarding practices to maximize levels of coarsewoody debris (CWD) in a dispersed harvesting setting in CoastalBritish Columbia.

The study comprised two components: the economic compo-nent was the responsibility of the Forest Engineering ResearchInstitute of Canada (FERIC), and the dead-wood componentwas the responsibility of the Vancouver Forest Region.

Broadly stated, the objectives of the study were:

Economic component

� Monitor and compare the logistics of conventional yard-ing with yarding where non-merchantable/low-value woodis marked to be left on site.

� Estimate the costs of loading, transporting, and sortingnon-merchantable/low value wood.

� Determine if marking of non-merchantable/low-valuewood after falling but prior to yarding is an effective andeconomically feasible method to increase post-harvest CWD.

Dead-wood (CWD) component

� Quantify differences in CWD attributes in terms of pre-vs. post-harvest, and conventional vs. modified bucking andyarding practices.

� Identify attributes of potential sources of CWD prior toharvesting, and compare to the attributes of post-harvestCWD.

� Quantify volume and piece density of CWD removedthrough post-harvest salvage.

The study involved modifying the bucking and yarding prac-tices currently used in Weyerhaeuser�s helicopter operations foruse in a ground-based harvesting setting, to:

1. maximize the retention of non-merchantable/low-valuewood in the dispersed setting without affecting cut controlvolumes or increasing volumes of billable residue and waste,and

2. improve harvesting productivity and profitability by re-ducing hauling costs and dryland sort accumulations.

This report provides detailed descriptions of the operational buck-ing, yarding, and loading phases of the study; further details aboutthe study�s background and rationale can be found in an interimreport prepared by the Vancouver Forest Region (Davis and Nemec2001). A glossary of terms appears in Appendix A.

2.0 SITE DESCRIPTION

The harvesting site selected for study (Block No.: UA 1063F �3057) is located up the Adams River in Tree Farm License 39

of Weyerhaeuser�s North Island Timberlands, Kelsey BayOperations. The opening is fairly homogeneous with respect toterrain, stand attributes, and site series. The forest is multistoriedand consists of overmature, 25�30-m-high western hemlock(Hw) and amabilis fir (Ba) over intermediate BaHw layers,including advanced regeneration 2�10-m tall. Crown closurevaries between 40 and 80%, structural diversity is average, andthe density of snags is low. The site series is predominantlyzonal.1 Advanced regeneration and vaccinium (30�50%) domi-nate the understory layers. The timber is characterized by highdecay, which has resulted in broken tops, conk, and basal scars.

3.0 DESCRIPTION OF METHODS AND PRACTICES

For the purposes of the study the harvesting site was dividedin two, with the road as the dividing line.

1. The Conventional Block (CON) was harvested by con-ventional practices.

2. The Mark-to-Leave Block (MTL) was harvested by buck-ing, yarding, and loading practices that were modified fromthose used in Weyerhaeuser�s helicopter harvesting opera-tions. These modified practices involved:

a) Bucking on site to create higher value logs (CHVL). Inthis approach, non-merchantable/low-value wood (e.g., ZGrade) is bucked and left in the setting.

b) Marking Z and Y Grade wood for the purpose of leav-ing on site (MTL). A scaler marked the non-merchantable/low-value wood with paint after falling and bucking, butprior to yarding.

c) Yarding only those pieces that were not marked with paint.

d) Loading only those pieces that were not marked withpaint.

The work was conducted by Weyerhaeuser�s operational har-vesting crews. Different falling crews were used in each block;however, there was some overlap with regard to yarding andloading operators. The Conventional Block was completed first,but this should not have had any effects on the results.

The crews were informed that a study was underway, and thatthey should follow standard procedures in the ConventionalBlock. The crews working in the MTL Block were given de-tailed instructions as to what would be required in the fallingand bucking, mark-to-leave, and yarding and loading phases.

3.1 Falling and Bucking Methods

Quality-control supervisors worked approximately ten days withthe fallers to ensure they were bucking to recover maximum log

1 R.A. Harder and L.W. Apedaile, Silviculture Prescription for BLK 3057,November 27, 1998; Weyerhaeuser, BC Coastal Group, Nanaimo, BC; internaldocument. M. Fidgeon, Coarse Woody Debris (CWD) Pilot Study – Field Assessment ofPotential Study Sites, November 21, 2000; Vancouver Forest Region, BCMinistry of Forests, Nanaimo, BC; internal document.

49



value, and limiting the amount of cull attached to merchantablelogs, and thereby increasing the volume of wood left on site asCWD without increasing the billable residue and waste volumes.

Prior to falling in the MTL Block, the fallers were given de-tailed instructions about bucking. The purpose and anticipatedbenefits were also reviewed. The fallers were instructed to as-sess for quality. The bucking was done so as to maximize valueand quality of the logs while minimizing cull (Figure 1). Loglengths were determined according to Weyerhaeuser�s log speci-fication card (Appendix B). Steps to minimize cull included:

1. Long butt to remove defect or rot.

2. Buck out conk.

3. Remove shattered portions.

4. Buck out portions of the log that would be graded as Yor Z Grade wood.

The following section of the report describes the standards forapplying these methods, and where applicable makes a com-parison between the Conventional Block and the MTL Block.

3.1.2 Long Butt to Remove Severe Defect or Rot

Long butting refers to cutting a short length, usually <5 m,from the butt of the log. This is done to remove severe defectfrom the log or to remove excessive butt flare or deformity. Thisis a common practice in conventional harvesting operations.

The long butt should be >3 m long to be classified as a log andbe graded as a Y or Z log. If the long butt is <3 m long it isclassified as bucking waste, not graded, and billed at full stumpagein the Residue and Waste Survey.

Three common reasons for long butting are:

i) Butt rot (rot or hole) (Figure 2).

If the rot or hole is >50% of measured butt diameter thenthe log should be long butted to a length >3 m.

ii) Water shake/checks (Figure 3).

Water shake refers to the separation of the annual rings.Check refers to a split in the wood that runs at right anglesto the grain. If the check or water shake is >50% of mea-sured butt diameter then the log should be long butted to alength >3 m.

iii) Deformities (Figure 4).

Deformities include forks and crooks.

3.1.3 Buck Out ConkConk is the fruiting body of a fungus. �A log with conk mayshow conk at the end of the log or may show conk in theknots. For logs with conk evident at the butt or top, the conk ispresumed to run ½ the length of the log to a maximum of 6m, or 3.6 m below the bottom knot showing conk and 2.4 mabove the top knot showing conk or whichever is greater�(BCMOF 1999). This log is Y Grade for the affected length.

If the conk is evident on the butt, then it is common practiceto long butt (Figure 5); however, if the conk is evident in themid section of the log and at knots, the conk may not bebucked out to ensure the specified log length is met (Figure6). In this case, the conk is bucked at the roadside or at thesort area.

If the conk occurs at the butt, then the rules outlined for longbutting apply (Figure 2). If the conk is in the mid section ofthe piece, then the conk is bucked out. The rule is to cut 3.6 mbelow the bottom-most affected knot and 2.4 m above thetop-most affected knot. This log section is graded as a Y or Zlog in the Residue and Waste Survey, depending on the per-centage of soundness. As demonstrated in Figure 5, buckingout conk can improve the value of the merchantable logs.However, these logs need to meet the minimum recovery speci-fications; for example, >3 m long and >17.5 cm at top. If thenon-affected section is <3 m then the conk is not bucked outand the entire piece is a Y grade.

3.1.4 Remove Shattered Portions

Bole shatter may occur when a tree falls. Western redcedar, aswell as clear, knot-free wood, are most susceptible to shatter.

In conventional falling, some shattered wood may be left onthe piece to ensure the specified log lengths are met. At the logsort, this wood is bucked off and generally used as hog fuelrather than pulp because debarking small shattered pieces isdifficult and expensive. If the shatter is somewhere in the middleof the piece, the standard is to remove 0.1 m on either side ofthe shatter, or buck through the shatter if it is still attached.This section is not recorded in a Residue and Waste Surveybecause it is part of the breakage percentage; for example, if itis <0.1 m long. For most Licensees, logs of higher grades arebucked to clean ends, while merchantable saw logs are buckedto a 60% shatter-free end. If a section of breakage <3 m inlength is bucked from a log, there are several ways its volumemay be accounted for:

1. Open Slash (Setting)��

a) If the large end is cut, the piece is classified as buckingwaste and the volume is billed and charged against the al-lowable annual cut (AAC).

b) If the large end is broken, the piece is classified as break-age and not scaled. The volume is assumed to be includedin the percentage of volume classified as breakage for AACcalculations.

c) A piece that is >3 m in length and is badly shattered, but,in the opinion of the residue and waste surveyor, will notwithstand yarding and loading, can be called breakage and isnot measured.

2. Accumulations��

a) Any piece with a cut end is classified as bucking wasteand is both billable and chargeable.

50



In this study, in the MTL Block, pieces with shatter ≥2.5 mlong,2 or a fractured section ≥3 m long, was bucked and left onsite. This piece is classified as Y Grade and is charged to the cutcontrol but not billed. If the piece is <3 m long, it is classified asbucking waste and is billable on a Residue and Waste Survey.

As shown in Figure 7, bucking out the shatter can reduce theamount of cull that is handled throughout the processing system.

3.1.5 Buck Out Y or Z Grade Wood

A Y Grade log is lower in grade than Utility (X Grade) andhigher in grade than Firmwood Reject (Z Grade). It is a chip-per log used for pulp. The economics of using Y Grade woodfor pulp depends upon the market conditions. Y Grade woodoften has large and frequent knots, deformities, defect, and/or spiral that restrict the cutting of merchantable lumber (Fig-ure 8). This Y Grade wood was marked-to-leave in the MTLBlock; its volume will be charged to the cut control but not billed.

Z Grade wood is not measured in a Residue and Waste Survey.Z Grade, or Firmwood Reject, wood is not usually used for pulp.This wood is typically <50% sound. (Refer to Appendix C.)

3.2 Mark to Leave

The mark-to-leave (or painting) phase, which occurred afterfalling and bucking were completed, but just prior to the yard-ing process, was done by licensed metric log scalers who werealso residue and waste surveyors.

They walked the entire block, painting blue spots on any piecesthat had been bucked off to minimize cull or because theywere below the minimum recovery specifications. Only Y andZ Grade pieces were marked. These blue spots were approxi-mately 20 cm2 and were painted on several locations on thepiece so as to be visible to the yarding engineer or the hookereven if the piece rolled.

3.3 Yarding and Loading

The yarding and loading crew received less instruction and su-pervision than the fallers received. The crew were asked not toyard or load any pieces with blue spots if possible. They were

also asked not to load any obvious cull logs that were not painted.The pieces with blue paint were to be used as a reference forcull logs. And, if pieces with blue spots were inadvertently yarded,the crew were asked not to load them.

The yarding and loading crews were visited by the quality-con-trol supervisor approximately every two weeks; in part, visitswere not more frequent so as not to skew the study results.

4.0 OBSERVATIONS

Relative to the operational aspects of the modified bucking,yarding, and loading practices used in this study, the followingobservations were made:

1. The bucking practices have their greatest application inold-seral Coastal forests because the associated timber tendsto have a high frequency of decay, waste, and breakage.

2. Fallers require on-site training and periodic monitoring toensure that modified bucking practices do not create buck-ing waste and to ensure log grades are properly assigned.

3. The size, frequency, and colour of the paint marks needto be tested at the start of yarding because visibility is influ-enced by such factors as yarding distance, slope, and terrain.

4. Where visibility is limited (due to yarding method, deflec-tion, and/or terrain), the yarding engineer requires the assis-tance of the second crew person to verify the presence orabsence of paint marks.

5.0 REFERENCES

BC Ministry of Forests. 1999. Scaling Manual, November 1999.Revenue Branch. Victoria, BC. http://www.for.gov.bc.ca/revenue/manuals/scaling/Contents.htm

��. 2000a. Provincial Logging Residue and WasteMeasurement Procedures. Revenue Branch, Victoria, BC.

Davis, G. and A. Nemec. 2001, in preparation. OperationalTrial to Evaluate the Effectiveness of Using Modified Bucking/Yarding Practices in Coastal Old-Growth Stands to MaximizeCoarse Woody Debris Levels in the Setting. Vancouver ForestRegion, BCMOF. Nanaimo, BC. Interim internal report.

6.0 ACKNOWLEDGEMENTS

The author is grateful to Gerry Davis, Bruce Markstrom, andKathi Hagan for their assistance in preparing this report.

2 A 2.5-m length is a subjective length at which point at least 3 m is bucked off.

51



Figure 1. Increasing log value through modified bucking. 3

3 The illustrations of logs in this report/appendix are not to scale; they are provided for general reference only.

52



Figure 2. Using long butting to remove butt rot.

53



Figure 3. Using long butting to remove water shake/checks.

54



Figure 4. Using long butting to remove deformities.

55



Figure 5. Using long butting to remove conk from the butt.

56



Figure 6. Using long butting to remove knots.

57



Figure 7. Using modified bucking to remove shatter.

58



Figure 8. Y and/or Z grade pieces that are not recovered.

59



APPENDIX B-1: GLOSSARY OF TERMS

BCMOF�British Columbia Ministry of Forests.

BUCKING WASTE�Pieces of trees cut to less than the mini-mum utilization length (3.0 m) and >50% sound.

BULL BUCKER�The faller�s foreman/supervisor.

BUTT CUT�The log closest to the stump. This cut can beidentified by the undercut showing at the large or butt end.

BUTT ROT�Conical rot occurring in the base of a tree andfound in the butt log after falling. If the log is <75% sound thefaller/bucker should long butt at least 3 m.

CHASER�A person who works in the log landing and whoseprimary job is to unhook the chokers from the logs as they arelanded at roadside. This person may help buck broken ends, etc.

CHECK�A split in the wood that runs at right angles to theannual rings.

CONK LOG�A log with conk showing at the end, or with conkknots on the log. The conk is presumed to run half the length ofthe log to a maximum of 6 m, or 3.6 m below the bottom-mostknot and 2.4 m above the top-most knot or whichever is greater.This area of the log is Y Grade for the affected length.

CULL LOGS�Logs that are graded as either Y or Z Grade,as determined by the British Columbia metric grading rules.

DEFECT�Irregularities in the stem or structure of a log thatimpede the cutting of merchantable lumber or chips (e.g., rot,shake, crooks, forks, spiral grain, large or frequent knots).

HEART ROT�Cylindrical rot which can occur in any por-tion of a tree. If heart rot is >75% of the end volume, aminimum 3-m piece should be removed.

HOG FUEL�Waste wood/bark produced at the dryland sort,and/or cull logs, that are ground up and used as a supplemen-tary fuel at pulp mills.

HOOKER�Head of the yarding operations; responsible forensuring the yarder and loader are properly positioned, therigging is set up for maximum safety and efficiency, and theoverall running of the yarding operation.

LOG�Any section of the bole, or of the thicker branches ofa felled tree, after trimming and cross cutting.

LONG BUTT�A short length, usually <5 m, cut from thebutt log to reduce the extent of severe defect or to removeexcessive butt flare or deformity.

MERCHANTABLE LOG�A log with knots that are smallenough to facilitate good, strong, general-purpose lumber atleast 2.5-m long and graded as better than Utility.

MINIMUM RECOVERY SPECIFICATIONS�In old-growth timber, this is a log which is ≥3.0 m long, ≥15 cm at thesmall end, and is X Grade or better. In second-growth timber,this is a log which is ≥3.0 m long, and ≥10 cm at the small end.

NET VOLUME �The firmwood volume of a piece of woodafter deductions for rot and voids.

PULP LOG�There are two types of �pulp� logs:

1. A log that is an alpha Y Grade or chipper, based onBCMOF�s metric log scaling rules.

or

2. A log that does not meet the industry�s current sort re-quirements for a peeler, lumber, shingle, or saw log.

RADS�The common unit for measuring log diameter, as perBCMOF scaling protocol. 1 RAD equals 2 cm in diameter.

SAW LOG�A log from which lumber of merchantable di-mensions can be cut.

SECOND CUT�This is the second log up the tree, althoughit may not be possible to tell a second cut from a third orfourth cut.

SLAB�A non-round (split) portion of the log, at least 10-cmthick and 10 cm in diameter.

TURN�One cycle of the yarding lines, for example, whenthe grapple travels from the yarder to the logs in the setting,grapples one or more, and returns to the landing.

WATER SHAKE�The separation of the annual rings in theend of a log.

X GRADE�A log ≥3 m long and ≥5 cm in radius where atleast 33 and 1/3% of the gross scale can be manufacturedinto lumber, and at least 35% of that lumber will be merchant-able. The net volume of X Grade and better logs scaled in aResidue and Waste Survey is billed to the Licensee and chargedto the AAC.

Y GRADE (Chipper)�A log lower in grade than Utility [X]and higher in grade than Firmwood Reject [Z]. This log is notbillable in a Residue and Waste Survey, but its net volume ischarged to the AAC.

Z GRADE (Firmwood Reject)� 1. A log where:

a) Heart rot or a hole runs the entire length of the log andthe residual collar of the firmwood constitutes <50% ofthe gross scale of the log,

or

b) Rot is in the log and the scaler estimates the net length ofthe log to be <1.2 m,

or

c) Sap rot or charred wood exists and the residual firmwoodis <10 cm in diameter at the butt end of the log.

2. That portion of a log that is <10 cm in diameter, or thatportion of a slab that is <10 cm in thickness.

60



APPENDIX B-2:WEYERHAEUSER’S SPECIFICATIONS CARD FOR FALLERS, WEST ISLAND TIMBERLANDS

61



APPENDIX B-3: EXPLANATION OF RESIDUE ANDWASTE BILLING

In 1988, the BC Ministry of Forests (BCMOF) began a pro-gram of measuring the net volume and quality of harvestingdebris. The material that was measured was charged to theallowable annual cut (AAC) and the avoidable portions werebilled at the full stumpage rate to the Licensee. The CuttingPermit document defines the portion of trees that are recov-erable, thus billable and avoidable waste.

In old-growth timber, a Licensee is usually required to recoverthat portion of a tree that is between a 30-cm-high stump anda 15-cm-diameter top. All portions of this tree that are X Gradeor better and >3 m long, must be recovered.

In a Residue and Waste Survey, pieces other than stumps areclassified either as logs or bucking waste. Logs must be gradedas per the BCMOF alpha grades. The net volume of any logthat is X Grade or better is charged to the AAC and is billedmonetarily to the Licensee. Y Grade logs are recoverable atthe Licensee�s option. If live Y Grade logs are recovered, theyare billed at $0.25/m3 and charged to the AAC. If the Licenseechose not to recover these Y grade logs, their volume is charged

to the AAC but they are not billed. Logs which are Y Gradeand come from a dead tree are Grade 5 and are not measured.Logs which are Z Grade or <50% sound are not measured at all.

Bucking waste is not allowed to be graded; as long as it is >50%sound and avoidable, the net volume is billed monetarily andcharged to the AAC.

If a log is to have cull portions removed to upgrade its value,this can be done without affecting the cut control volume orincreasing the billable volume. This is accomplished by remov-ing only severe rot or defect from a log, and ensuring the lengthremoved is >3 m long. These two requirements accomplishfour things:

1. This length ensures the piece is a non-billable log (Y or ZGrade), and not bucking waste.

2. The parent log may be upgraded thereby, making it morevaluable (see Figures 2�6).

3. Creates large sized CWD dispersed across the setting atlittle or no cost to the Licensee.

4. Reduces volume of cull logs and waste wood at the landing.

62



APPENDIX B-3:WEYERHAEUSER’S GUIDE TO LOG IMPROVEMENT

63

Research Disciplines: Ecology ~ Geology ~ G

eomorphology ~ Hydrology ~ Pedology ~ Silviculture ~ W

ildlife

Technical Report TR

-017 March 2002 R

esearch Section, Vancouver Forest Region, BC

MO

FAPPENDIX C

SUMMARY OF CWD DENSITY AND VOLUME STATISTICS FOR BOTH STUDY BLOCKS,USING LENGTH AND DIAMETER CLASSES FROM THE LITERATURE

tolP).on(

retemaiDssalC)mc(

ssalChtgneL

latoTm1< m3-1 m7-3 m7< m5< m01<

.on()ah/seceip m( 3 )ah/







32 £ 02 0.83±8.431 3.0±0.1 1.24±2.981 7.0±5.3 2.6±1.13 4.0±8.1 5.2±1.5 4.0±7.0 3.3±9.9 4.0±1.1 9.0±0.1 2.0±2.0 6.55±9.743 1.1±7.6

04-1.02 3.22±5.77 2.0±7.0 1.7±3.83 5.0±9.2 2.4±3.43 6.0±1.5 7.6±8.63 9.1±1.31 0.7±5.84 0.2±3.51 6.5±0.22 7.1±4.9 5.03±6.181 5.2±2.12

08-1.04 9.0±9.2 1.0±2.0 6.5±1.23 3.1±4.7 1.5±9.24 5.3±8.12 1.4±1.04 8.31±7.08 9.4±2.45 3.41±4.09 4.3±6.72 7.21±7.86 6.01±7.311 7.51±8.801

08> 0.0±0.0 0.0±0.0 0.1±0.2 3.0±5.0 2.2±2.9 7.2±1.11 4.2±7.51 4.31±6.76 7.2±7.91 4.31±2.37 9.1±7.11 9.11±1.95 9.2±8.62 7.31±2.97

03-51 5.63±2.021 4.0±1.1 9.32±8.201 5.0±8.2 2.6±9.34 7.0±9.3 7.6±3.82 6.1±9.6 9.7±5.14 6.1±5.8 0.4±6.11 2.1±7.3 5.54±7.182 1.2±3.41

£ 03 3.34±4.581 4.0±4.1 4.24±7.412 8.0±7.4 0.7±4.15 7.0±2.4 7.6±3.82 6.1±9.6 0.8±8.14 6.1±5.8 0.4±6.11 2.1±7.3 4.06±2.564 3.2±7.61

06-1.03 8.31±7.82 2.0±4.0 9.4±2.23 8.0±2.5 8.3±8.14 2.1±8.21 8.4±1.23 9.3±9.82 8.4±2.34 0.4±3.33 6.4±9.32 0.4±7.32 8.61±4.921 4.4±4.64

06-1.04 8.0±7.1 0.0±1.0 2.4±3.91 7.0±5.3 2.3±8.72 2.1±1.01 3.2±5.81 6.3±1.22 3.2±7.62 7.3±5.52 3.2±6.21 8.3±8.71 2.6±1.56 1.4±2.53

06> 6.0±2.1 1.0±1.0 3.3±7.41 2.1±4.4 7.3±3.42 1.4±8.22 7.4±4.73 7.22±2.621 5.5±2.74 4.32±1.831 9.3±7.62 5.91±1.011 1.8±5.57 3.42±8.251

05-03 6.31±8.72 2.0±4.0 2.4±7.52 6.0±4.3 5.3±9.13 0.1±1.8 5.4±5.32 2.2±9.41 0.5±7.23 4.2±2.81 3.4±3.71 1.2±1.21 1.71±9.301 7.2±1.62

08-05 9.0±5.2 1.0±2.0 0.4±2.32 1.1±2.6 6.4±0.23 5.3±9.81 1.4±6.33 0.41±3.57 9.4±5.44 5.41±9.38 4.3±3.32 9.21±6.46 1.9±8.88 0.61±6.99

05> 8.0±1.2 1.0±2.0 8.3±0.32 2.1±3.6 2.5±8.63 5.4±9.72 2.5±6.74 8.22±9.041 0.6±7.06 4.32±2.451 2.4±8.33 3.91±9.121 5.9±0.701 6.42±4.471

latoT 9.84±3.512 4.0±9.1 4.14±6.162 6.1±2.41 8.9±4.711 6.4±8.93 9.8±8.79 1.32±0.261 1.11±2.231 0.42±0.081 6.7±3.26 9.91±4.731 1.07±0.076 9.42±9.512

64

Forest Research Technical Report - British Columbia · 2007-02-25 · TR-017 Ecology March 2002 Technical ReportForest Research Vancouver Forest Region 2100 Labieux Road, Nanaimo,

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