Forest Investment Account (FIA) - Forest Science Program
FIA Project Y072184

    Predicting Advanced Regeneration Density in Lodgepole Pine Stands in the Northern Interior of British Columbia: Year 2
 
Project lead: Burton, Phillip
Contributing Authors: Burton, Philip J.; Coates, K. David; DeLong, Craig; Sachs, Donald L.; Hamann, Andreas; Brooks, Darin W.
Imprint: Prince George, B.C. : Canadian Forest Service; University of Northern British Columbia, 2007
Subject: Forest Investment Account (FIA), Pinus Contorta, British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Description:
The proposed research addresses FSP’s Timber Growth & Value priorities for complex stands, particularly 4.1, 'Stand and forest dynamics following mountain pine beetle.' Rationale -- The scale of the current mountain pine beetle (MPB) outbreak is such that many pine beetle-infested stands in the Central and Northern Interior of B.C. may be left untreated and unsalvaged. Unsalvaged stands will not undergo silvicultural treatment, which raises questions about their ability to regenerate, their future growth and yield, and the implications of these uncertainties to future timber supply. Which unsalvaged stands, or portions of stands, should be rehabilitated in order to assure adequate stocking and a continued timber supply? Regeneration is assumed to be a uniform 20 years in the Chief Forester’s October 2003 timber supply analysis of the outbreak’s impacts, yet observations suggest that some stands may regenerate to non-pine species sooner than this. Since forest inventories do not document understory conditions, no system currently exists to predict which stands will have advanced regeneration suitable for release upon canopy death, nor which stands are so dominated by brush that long regen delays can be expected. The proposed research will take a ground-truthed, landscape-level approach to predicting, mapping, and prioritizing stands according to their need for salvage or rehabilitation. Research Methods -- Factors contributing to the abundance of spruce and fir seedlings in the understory of pine stands include: - site series (preliminary observations suggest spruce and fir regeneration can often be found on modal 01 site series, with little regeneration on drier 02 site series, while heavier brush may obstruct regeneration on 05 and 06 site series); - stand age and structure (especially canopy openness; also some advanced regen of pine on 02 sites); - the proximity (and direction; prevailing winds are from SW) of seed-producing spruce or fir trees; and - biogeoclimatic factors associated with sub-zone differences and elevation (more subalpine fir are found in the cooler moister locations). We will focus on stands suffering from 'green-' or 'red-attack,' or not yet subject to pine beetle mortality, as we need to document pre-outbreak canopy conditions. Our objective is to sample the distribution of shade-tolerant conifers developing in the understory of undisturbed pine stands, not natural regeneration through new inseeding following canopy death. Sampling design will be based on a stratified random selection of 25 to 50 pine-leading mature forest areas (within 200m of road access) in each of three subzones -- SBSmc, SBSdk, and SBSdw. Candidate sampling areas will be further stratified to represent: - stand ages 60 through >140 yrs of age; - low, medium and high elevations within the subzone; and - dry/poor, mesic/modal and rich/moist sites. Site selection will be further facilitated by GIS analysis (e.g., highlighting of large pine-leading stands adjacent to non-pine conifer stands), and by drawing upon the local knowledge and maps of cooperators. Within selected stands, 5 to 10 plots will be sampled at regular intervals along transects. Plot centers will be GPS mapped onto the forest cover layer to determine the position (distance and direction) of each plot relative to the nearest mature stands containing interior spruce or subalpine fir. Plot centers will be marked with rebar to facilitate future relocation (as described in a companion proposal by C. DeLong). Tree seedlings and saplings (total and well-spaced) will be tallied by size class and species within 4 quadrants of a 100 m2 (5.64 m radius) circular plot. A hemispherical canopy photograph will be taken at plot center and in each quadrant, to be analyzed for canopy cover and percent above-canopy radiation. Pine basal area will be recorded for each plot, and the abundance of mature living conifers in or near each plot will be recorded by species, either in terms of basal area, or in terms of distance and direction. Site series will be determined using a shovel pit and indicator plant species. Some of the factors measured in the field plots and expected to affect regeneration densities can be predicted from various GIS map layers. These map data will be used to predict expected densities of advanced regeneration, with a subset of these predictions to be tested in the third year of the project, in collaboration with colleagues working on related projects. The three selected subzones will also allow us to infer the degree to which climate and some floristic differences can affect stand recovery trajectories.
Related projects:  FSP_Y061184FSP_Y083184

    Deliverables:

Progress Report Year 2 (0.3Mb)
Poster (0.8Mb)
Report for Chief Forester (0.4Mb)
BCEJM Article, Vol. 7, No. 2, Art. 1.

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Updated August 16, 2010 

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