The effects of forest gap size on Douglas-fir seedling establishment in the southern interior of British Columbia

This study focuses on seedling germination and survival of Douglas-fir (Pseudotsuga mensiezii var. glauca [Beissn.] Franco) seedlings in an Interior Douglas-fir (IDF) biogeoclimatic zone forest. Plots were established in the centers of naturally occurring forest gaps of varying sizes (large, medium, and small) and Douglas-fir seedlings were planted with or without the ability to associate with ectomycorrhizal (EM) networks. As seedlings cannot make EM associations until one or sometimes two seasons of after germination, this paper does not report data on EM effects, but refers to literature on the influence of EM networks. A three factorial design was used to assess the effect of gap size and mycorrhizal influence with 9 replications on seedling germination and survival. Data was collected on 3 separate days during the 2011 growing season and included germination counts as well as volumetric soil moisture content data using a ML2 theta probe®. Results for germination were not normally distributed therefore rejecting parametric statistics; however, it was detected that large gaps had lower seedling survivability even though results are not significant. Moisture content data showed that soil moisture could have played a role in tree survivorship but more data is necessary.Forestry, Faculty ofUnreviewedUndergraduat