Mature forest stands dominated by lodgepole pine were sampled for the density and composition of advance regeneration in their understories. A total of 302 sample plots, 221 of them along 30 transects in lodgepole pine stands, and 81 plots in 26 adjacent 'seed source' stands dominated by spruce, fir or Douglas-fir, were located in the SBSdw3, SBSmc3 or SBSdk biogeoclimatic units, in the Prince George and Vanderhoof Forest Districts. When combined with analogous data collected by collaborators (including samples from the SBSdw2 and SBSmc2 variants), a total of 522 plots in pine-leading stands were available for analysis. These data indicate an overall average of 2431 stems/ha of conifer regeneration in the understory of pine stands, and that 48% of sites had at least 600 stems/ha. Regeneration densities were highest in the SBSmc2 variant, followed by the SBSmc3 variant. Relationships to the prevalence of non-pine conifer trees in the sampled stands were inconsistent, as were the effects of proximity to adjacent non-pine conifer stands. Tree species differences in these patterns, site series effects, and directional effects remain to be resolved. Results indicate that some stands have fully stocked understories when the mountain pine beetle kills the overstory, and that such stands should be identified and given a lower priority for salvage harvesting.
Philip J. Burton.
Brooks, Darin W., Burton, Philip J.. 2006. Predicting Advanced Regeneration Density in Lodgepole Pine Stands in the Northern Interior of British Columbia: Year 1 progress report. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2006MR277