Long-term recovery of forest structure and composition after harvesting in the coastal temperate rainforests of northern British Columbia

Abstract

We examined young harvested (41–100) and naturally disturbed mature (101–250), and old (>250) temperate rainforests on the central and north coast of British Columbia to quantify the recovery rates of tree size, density, and species composition of young harvested stands towards old-growth condition. Significant variations in recovery rates were noted due to differences in site productivity. Nonmetric multidimensional scaling (NMS) ordinations, Multi-response Permutation Procedure (MRPP) summary statistics, and Sorensen’s similarity coefficients (SC) all indicate moderate levels of similarity between young and old stands. Rich sites show greater similarity between young and old forests (SC=55%) than do medium sites (SC=41%), indicating more rapid recovery. Differences in tree species composition, especially for western redcedar, were apparent among young and older forests on all sites. We believe that proactive management is required to ensure that western redcedar, an ecologically, culturally, and economically valuable tree species, is maintained as a significant component in the managed second-growth forests of central and north coast British Columbia. Our results indicate that second-growth forests, while not as structurally developed as old-growth, are developing some ecologically important structural characteristics at relatively young ages (80–100years) and as such, contribute towards ecological integrity and biodiversity of the coastal temperate rainforest landscape.