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 (Eng et al. 2005). 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. What proportion of pine-leading stands in a given area can be expected to have fully stocked understories if they are not salvaged and artificially regenerated? Can we predict where to find fully stocked and unstocked conditions, based solely on available map data, so we can give priority to harvesting or rehabilitating the latter? Since forest inventories do not document understory conditions, no system currently exists to predict which stands will have adequate stocking of advanced regeneration suitable for release upon canopy death, nor which stands are so dominated by brush that long regeneration 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. Data on the extent of advanced regeneration will also contribute to improved growth and yield prediction of irregular stands, and to projections of mid-term timber supply (e.g., FSP projects M075015 and M075040). The proposed research will be the third and final year of a project to calibrate landscape-level tools for predicting the amount of existing conifer regeneration (particularly interior spruce, subalpine fir and Douglas-fir) in the understory of lodgepole pine leading stands at the time of MPB attack. Basic GIS tools of this nature are already being employed by forest planners, and would greatly benefit from science-based refinement. The contributing influence of site series, stand condition, and seed source proximity are being evaluated in each of three Sub-Boreal Spruce subzones: SBSdw, SBSdk, and SBSmc. Data are being compiled from existing archival sources, supplemented with transect sampling of pine-dominated stands, including new data shared from FSP projects Y072072 and Y072148. GIS analysis has intersected topographic data (TRIM coverages), forest cover (VRI) data, and TEM or PEM designations (where available), and determined sample plot distances from the closest spruce- and fir-leading stands; subsequent algorithms derived from statistical analysis can assign categories of understory density and stocking expected at different locations in different pine stands. This project will enhance our understanding of the dynamics and resilience of a variety of lodgepole pine forests, and their expected responses to mountain pine beetle attack. A prototype model has been developed which can be used to predict both absolute densities of advance regeneration (by species and size class), and stocking levels at user-defined thresholds of acceptable species and spacings. Model output can then be used to prioritize stand harvesting operations on the basis of the probability of natural stand recovery. During this final year of the project, limited field sampling will be conducted to fill out a few weaknesses in existing data, and the prototype model will be tested on an independent dataset and refined; this work will collectively constitute the Master?s thesis of Darin Brooks at UNBC. All field data will be archived and made available for general use, and the modeling tools and procedures will be packaged and distributed at one or more training sessions for forest planners and managers, to be held at the UNBC GIS lab, as well as posted on the web.
Burton, Philip J., Brooks, Darin W.. 2008. Predicting Advanced Regeneration Density in Lodgepole Pine Stands in the Northern Interior of British Columbia. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2008MR181
Topic: FLNRORD Research Program
Keywords: Forest, Investment, Account, (FIA), British, Columbia
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