1 Wildlife Tree Retention
Apr 01, 2015
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Wildlife Tree Retention
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Wildlife tree retention
•One of most valuable components of stand-level biodiversity
•Over 80 species of wildlife are critically dependent on wildlife trees
•WTR is an important part of forest stewardship and ecosystem integrity
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Wildlife tree retention
Legal Definitions
Wildlife tree - a tree or a group of trees that are identified in an operational plan to provide present or future wildlife habitat (OPR sec. 1)
Dangerous tree - any tree that is hazardous to workers because of location lean, physical damage, overhead hazards etc. (WCBR sec 26)
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Ecological Guiding Principles
Choose wildlife trees considering:
• areas with valuable wildlife tree attributes
• uncommon species (with wildlife value)
• leaving a range of patch sizes and individual retention
• interpatch distance (500 m)
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Ecological Considerations
• Retention is for a minimum of one rotation
• Design patches to minimise windthrow
• If no valuable trees then choose for long term retention
• leave downed trees for CWD
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Salvage
• THPR Sec. 28 - no salvage in WTP unless approved in SP or in writing from DM
• Salvaged WTP’s should be replaced
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Rocks, swamps & marginal areas
• Max of .25 ha of non-treed area within a patch
• marginally treed areas count as a % of full stocking
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Seed and Shelterwood trees
• Can count to retention target if left for full rotation
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Stubbing
• Encouraged as compliment for wildlife tree retention
• Not recommended as contributing towards retention target
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Wildlife tree retention
• Forest Practices Code Timber Supply Analysis document (Feb 96) estimated that wildlife tree retention would have a
– 1.8% Provincial impact on timber supply, or
– 2.8% Provincial impact in the absence of LU objectives for OGMAs
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Wildlife tree retention
• Why is WTR being addressed through landscape unit planning
– LU objectives will ensure a sound legal basis for WTR management
– FDP is guided by and must be consistent with the HLP objectives
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Wildlife tree retention
What needs to be done?
– Calculation of WTR
– Determine total WTR %
– Set THLB cap (default is 50% or 25%)
– Setting WTR objectives
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Wildlife Tree Retention - Calculation
LU BECSubzone
CrownForested
(NC+THLB)
THLB %Subzoneavailable
forharvest
% THLB
harvested
TotalWTR
%
A SBSdkESSFmc
58 95713 709
49 52410 967
84%80%
30%10%
8 6
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Table A3.1
% of BEC subzone in LUavailable for harvest
% areaharvestedwithoutWTR 90 70 50 30 10
1030507090
79111315
5791113
357911
13579
01357
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TAUP=NAR + WTP + RRZ
WTPNAR
RRZ
WTP
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WTR- Variation in THLB cap
• main reason for allowing variation is to ensure subzones with little non-contributing have adequate WTR
• calculated PRIOR to setting LU objectives
• result is:
– varies THLB cap
– overall impact stays constant
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Wildlife tree retention - calculation
• Determine the THLB WTR target
– interior example - maximum 50% of total WTR target will be retained from the THLB.
– Calculate the THLB WTR target hectares by multiplying the total WTR percentage by 50% and by the crown forested area.
– 8% x 50% x 58,957 = 2,358 hectares
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WTR Spread Sheet A B C D E F G
Sub-zone
TotalWTR%
THLB
WTR %
CrownForest
TotalWTRha
THLBWTRha
50%WTR habaseline
SBSdk
ESSFmc
8%
6%
60%(4.8)
30%(1.8)
58957
13709
4717
823
2830
247
2358
411
SBSdk
SBSmc
ESSFmc
5%
6%
3%
60%(3.2)
40%(2.4)
27%(0.8)
13790
49392
11134
690
2964
334
414
1185
90
345
1482
167
TOTAL 4766 4763
B – derived from LUPG appendix 3 E = B x D
C – default is 50% -interior (bracketed #, B x C) F = C x E
D – landscape equivalent of TAUP G = .5 x B x D
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Stand level variation
• LU objective may allow variation at the stand level for biological reasons
• Controlled within each FDP
• Total WTR % objective and THLB cap met over the cutblocks within the FDP without exceeding the THLB cap
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Wildlife tree objectiveRetain 8% of each cutblock within the SBSdk as
wildlife trees subject to the following:
– All NC with suitable wildlife trees must first be used to achieve the overall cutblock target
– A maximum of 4.8% of each cutblock can be retained for wildlife trees located in the THLB
– It is acceptable to vary from the 8% and/or 4.8% for biological reasons, provided the average of the cutblocks within the SBSdk equal the 8% and up to 4.8% when averaged over all cutblocks in the SBSdk subzone within the FDP area.
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Wildlife tree strategy
• Example Strategy
– Every block should have some area reserved for WTR
– Where practical, retain wildlife trees in both patches and individually
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Wildlife Tree Retention
• Tracking
– SP mapping to .25 ha
– Forest Cover mapping 2 ha and greater
• Auditing/Monitoring
– to be based on aggregate of many SPs
– developed over next several years
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Wildlife Habitat Value
Wildlife Tree Value Characteristics
HIGH
Has at least 2characteristics fromadjacent column
Internal decay Crevices Large brooms Active or recent wildlife use Current insect infestation Tree structure good for wildlife Largest trees and vets Locally important tree species
MEDIUM Large stable trees likely to develop 2or more of the above attributes
LOW Trees not covered by high or medium