Succession in sub-boreal forests of West-Central British Columbia

Structural and compositional changes were analysed over the course of 400+ yr of post-fire succession in the sub-boreal forests of west-central British Columbia. Using a chronosequence of 57 stands ranging from 11 to 438 yr in age, we examined changes in forest structure and composition with complementary PCA and DCA ordination techniques. To determine stand ages and timing of tree recruitment, approximately 1800 trees were aged. Most early successional forests were dominated by Pinus contorta, which established rapidly following fire. Abies lasiocarpa and Picea glauca ×engelmannii were also able to establish quickly, but continued to establish throughout the sere. Few Pinus contorta survived beyond 200 yr, resulting in major changes in forest structure. In some stands P. contorta never established, which led to considerable variation among stands less than 200 yr old. The oldest forests converged on dominance by Abies lasiocarpa. Vascular plant diversity decreased during succession whereas canopy structure became more complex as gap dynamics developed. Although these sub-boreal forests contain few tree species, successional changes were pronounced, with structure changing more than composition across the chronosequence. Abbreviations: CWD = Coarse Woody Debris; DCA = Detrended Correspondence Analysis; DBH = Diameter at Breast Height; PCA = Principal Component Analysis. Nomenclature: Douglas et al. (1989–1994).