Site Index estimates by Site Series (SIBEC) Okanagan TSA 2008 Project: SOTSA22 4948003 Contract Report December 4, 2008 To: Glen Dick, RPF Executive Director Okanagan Innovative Forestry Society R.R. #2 4280 Highway 6 Lumby, B.C. V0E 2G7 From: Alex Inselberg, M.Sc. Consulting in Vegetation Ecology and Soils 123 Glenmary Rd. Enderby, B.C. V0E 1V3 Tel. 250-838-2141 E-mail: [email protected]and Tanya Seebacher, M.Sc. Consultant 10870 Tyndall Road Winfield, BC V4V 1N8 Tel. 250-766-5051 E-mail: [email protected]
24
Embed
SIBEC OKANAGAN TSA - British Columbia · (SIBEC) for determination of annual allowable cut (AAC). Results showed first approximation SIBEC estimates were higher than SI estimates
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Site Index estimates by Site Series (SIBEC)
Okanagan TSA 2008
Project: SOTSA22 4948003 Contract Report
December 4, 2008
To: Glen Dick, RPF Executive Director Okanagan Innovative Forestry Society R.R. #2 4280 Highway 6 Lumby, B.C. V0E 2G7
From: Alex Inselberg, M.Sc. Consulting in Vegetation Ecology and Soils 123 Glenmary Rd. Enderby, B.C. V0E 1V3 Tel. 250-838-2141 E-mail: [email protected]
and Tanya Seebacher, M.Sc. Consultant 10870 Tyndall Road Winfield, BC V4V 1N8 Tel. 250-766-5051 E-mail: [email protected]
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 2 of 24
Acknowledgements
The support of Glen Dick and the Okanagan Innovative Forest Practices Society (OIFS)
is gratefully acknowledged (see http://www.okanagan-ifpa.org/index.html).
We thank Shikun Ran of Timberline Natural Resource Group in Kelowna for spending a
day with us in the field, as part of his quality assurance process. This allowed us to
discuss a variety of important field methodology details. He also helped us with plot
location, tree selection, soil pit excavation, and assorted other tasks. Tanya and I both
really appreciated Ran’s cooperation.
We thank Bob Macdonald, Growth and Yield Forester, Southern Interior Forest Region at
the Ministry of Forests and Range in Kamloops, for continuing to help us resolve a variety
of important field methodology questions. Thanks are also extended to Mike Ryan,
Research Ecologist, Southern Interior Forest Region, for helping us resolve a number of
site classification problems and questions.
Last, but not least, we thank Gordon Nigh, Strategic Analyst at the Ministry of Forests in
Victoria, who also provided helpful advice on important methodology questions.
Appendix 3. Sample plot and track navigation maps. _____________ 18
Appendix 3.1 Plots 4592 – 4594 off Bear Cr FSR and Esperon Lake FSR, NW from Kelowna. __________________________________________________________ 18
Appendix 3.2 Plot 3673 off Mable Lake Rd and Brash Cr Rd E from Enderby. ___ 19
Appendix 3.3 Plots 3677- 3678 off Hwy 6, E from Vernon and N from Lavington up Noble Canyon Rd and Coldstream FSR. _________________________________ 19
Appendix 3.4 Plot 4551 off Hwy 6, E from Vernon and S from Lavington. _______ 20
Appendix 3.5 Plots 3671, 3672, 3674-3676 and 3679-3681 off Hwy 6, E from Lumby, S on Creighton Valley Rd and off Harris Cr Rd. _____________________ 21
Appendix 3.6 Plots 3670, 3793, 3794, 3796-3800 and 4595-4600 off Hwy 6, E from Vernon, S from Cherryville, and off Kettle River FSR. _______________________ 22
Appendix 4. Record of resolved 2005 versus 1990 sample plot site classifications for 2006 and 2007 SIBEC data. ____________________ 23
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 4 of 24
Table of Figures
Figure 1: Histogram showing the distribution of the age classes sampled in the 2008 SIBEC Okanagan project __________________________________________________ 7
Figure 2: Sample plots and tracks overview map for 2008, see map details in Appendix 3. ___________________________________________________________________ 11
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 5 of 24
Introduction
The purpose of the current project is to continue building SIBEC site index-site unit
reference tables in the Okanagan TSA, by increasing sample sizes to the required
minimum for second approximation SIBEC (total of 7 trees required in each site series).
SIBEC was initiated in 1994 to fulfill the demand for better site index estimates than those
acquired from the forest inventory in old-growth stands. In 2001, at the request of B.C.’s
Chief Forester, research was conducted to determine the suitability of PEM site series
mapping and Site Index by BEC (Biogeoclimatic Ecosystem Classification) site series
(SIBEC) for determination of annual allowable cut (AAC). Results showed first
approximation SIBEC estimates were higher than SI estimates currently used by the
forest industry. Although the AAC determination results were positive on test locations for
the combination PEM/SIBEC approach, substantial additional data were required for
priority BEC site series in order to facilitate operational second approximation SI
estimates. Subsequent SIBEC second approximation estimates of productivity have
commonly continued to be higher than forest inventory estimates of productivity for old-
growth stands (Mah and Nigh, 2003).
Site series are, by definition, relatively uniform with regard to climate and soil conditions
(Pojar, Meidinger and Klinka, 1991). Individual site series (e.g. ESSFxc2/08 ‘Bl – Valerian
– Globeflower’) are thus polygons on the landscape with an overall similar site quality.
Since site index, and hence volume or biomass production, tends to be closely correlated
with site quality, it follows that site index is predictably similar for a given tree species
throughout the distributional range of any given site series, in the absence of localized
site quality or biotic impacts (cf. SIBEC sample plot and tree selection criteria).
The sample plot and sample tree selection criteria have been designed to minimize bias,
in order to support the development of reliable site index – site series relationships.
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 6 of 24
Methods
SIBEC data collection methodology, as described in the document at the following link:
http://www.for.gov.bc.ca/hre/sibec/documents/standards.pdf (ver. 2, 2007 revision) was
consulted frequently.
Reduction of tree sampling bias
In recognition of the fundamental importance of obtaining site index estimates which best
reflect the normal population, two or more candidate tree species were typically sought
(e.g. Fdi + Sxw + Cw) within close proximity of a potential sample plot (uniform site series
and stand conditions throughout). Prolonged searches for single sample trees with site
index values superior to those thus far documented were not undertaken, as this
undermines the intention, validity and integrity of the SIBEC program.
However, it is realized that tree selection criteria as defined in the above SIBEC
methodology already introduces considerable bias in favor of trees with above average
qualities and growing conditions. By looking for sample sites with two or more candidate
tree species the educated assumption was made that sample trees which all have
abnormal site indices are less likely to be sampled. Furthermore, it is acknowledged that
a sample size of 7 trees per species and site series combination, is a minimum, and is for
all intensive purposes likely too small a sample size. Thus, if unbiased site index values
for more than 7 replicates can be efficiently gathered, this is more than desirable.
During this work, the entire range of stand ages (20-120 years) was sampled, aiming, in
particular, for 40-60 (50) years old stands (Figure 1). Since most BC Interior managed
forests are younger than 30 years, harvesting will continue largely in existing mixed
history older stands for the next 50+ years. Since the Interior managed forests will likely
not be harvested until around 2060, when they are closer to 80 years old, it is helpful to
collect samples from a broad range of tree ages. Sampling younger stands exclusively,
where their ages are lower than their predicted site index benchmark age may create
needless risk and uncertainty. Furthermore, younger trees in cutblocks are more likely to
have been affected negatively by recent extreme weather conditions such as the severe
droughts in our area in 1998, 2003 and 2004. Larger, older trees, with more established
root systems, will generally not have been as seriously impacted by extreme climate
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 9 of 24
height / diameter adjustment and these are highlighted in red in the Appendix 1 summary
table.
Sample tree increment cores were sealed within vented and labeled plastic straws for
refrigerated storage, prior to being sent to Clive Dawson, Analytical Laboratory
Supervisor at the B.C. Min. For. Research Branch, Forestry and Technical Services in
Victoria.
Backup scans of all the field data cards were made and e-mailed to several different
addresses in order to avoid data loss. Representative site photos taken at each sample
plot are presented in Appendix 2 and are also included on the project CD.
Data were entered into VENUS 5.1 (MOE/MOF upgrade of VENUS 4.2 MOE) data entry
program using the FS882 field form option. The data were finally submitted to Shirley
Mah upon project completion in early December.
Resolution of site classification issues from 2006 and 2007
In both 2006 and 2007 the Okanagan TSA SIBEC samples were selected, as well as
identified in the field, with reference to the new revised field guide to site identification for
the Southern Interior (Lloyd, D., M. Ryan, N. Brand, M. Doney, V. Larson and J.
MacDonald, 2005). It was not until early 2008 that it was discovered the SIBEC sampling
plan was still being developed around the original 1990 Kamloops Forest Region site
classification (Lloyd, D., K. Angove, G.D. Hope, and C. Thompson, 1990). This in itself
would not have been a problem, except that the 1990 and the 2005 classifications are not
entirely synonymous.
As mentioned above, the 1990 site classification was used for the 2008 sampling. Since
the 2005 site classification sometimes uses site series numbers and names not
synonymous with the 1990 classification, the two classifications are not always
interchangeable. Consequently, since it was too late in the season to resolve the 2006
and 2007 classification issues, the Okanagan sampling avoided BEC units sampled in
2006 and 2007. Appendix 4 decodes the various differences between the 2005 and 1990
classifications, as applicable to the 2006 and 2007 Okanagan TSA SIBEC data.
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 10 of 24
Hopefully, by 2009, the existing SIBEC Okanagan TSA database will have been
reassessed to uniformly reflect only the 1990 site classification.
Results and Discussion
Twenty-nine plots and approximately 80 trees were located and sampled this summer in
the northern half of Okanagan TSA (Figure 2). The short list of summary information for
candidate sample trees is presented in Appendix 1. A set of contact sheets with the
sample plot representative photos is provided in Appendix 2. Individual maps showing
plot locations and tracks within the six general sampling locations are provided in
Appendix 3.
SIBEC field data were entered using VENUS 5.1. After resolution of certain quality
assurance questions, as well as laboratory verification of tree ages, the data were
submitted to SIBEC Research staff in Victoria in early December 2008.
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 11 of 24
Figure 2: Sample plots and tracks overview map for 2008, see map details in Appendix 3.
Site index estimates by site series (SIBEC) in Okanagan TSA – 2008 ________________________________________________________________________
Alex Inselberg and Tanya Seebacher Page 12 of 24
Literature Cited
Lloyd, D., K. Angove, G.D. Hope, and C. Thompson. 1990. A Guide to Site Identification and Interpretation for the Kamloops Forest Region. Research Branch. BC Min. For., Victoria, B.C. http://www.for.gov.bc.ca/hfd/pubs/Docs/Lmh/Lmh23.htm Lloyd, D., M. Ryan, N. Brand, M. Doney, V. Larson and J. MacDonald. May 2005. Site Classification for 52 Biogeoclimatic Units in the Southern Interior Forest Region. Draft. BC Min. For. Kamloops. http://www.for.gov.bc.ca/ftp/RSI/external/!publish/Dennis_Lloyd_BEC_Materials/ Mah, S. and G.D. Nigh. 2003. SIBEC site index estimates in support of forest management in British Columbia. Res. Br., B.C. Min. For., Victoria, B.C. Tech. Rep. 004. http://www.for.gov.bc.ca/hfd/pubs/docs/tr/tr004.htm
Internet Resources Cited
SIBEC Sampling and Data Standards (Version 5.2): http://www.for.gov.bc.ca/hre/sibec/documents/standards.pdf (May 2007)