Canadian Forest Service Publications
Chronosequences for research into the effects of converting coastal British Columbia old-growth forests to managed forests: an establishment report. 1998. Trofymow, J.A.; Porter, G.; Blackwell, B.; Arksey, R.; Marshall, V.; Pollard, D. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC. Information Report BC-X-374. 137 p.
Issued by: Pacific Forestry Centre
Catalog ID: 4898
A program of multidisciplinary research was initiated in 1991 by the Canadian Forest Service to study the changes caused by converting old-growth coastal temperate forests to managed forests. In 1992, plots were established on ten sites on southern Vancouver Island — five sites in Douglas-fir dominated stands on the dry leeward east side of Vancouver Island in very dry variants of the coastal western hemlock zone (CWHxm), and five sites in western hemlock dominated stands on the wetter windward west side of the island in very wet variants of the zone (CWHvm). Each site contained a basic suite of four seral stands — a chronosequence — representing four stages of stand development: regeneration, immature, mature and old growth. Chronosequences were selected so that stands within a site were on similar, slope, elevation and aspect. Most second-growth stands selected were of harvest origin and burned, though mature stands at three sites were of wild–fire or landslide origin.
This report details the background to the establishment of the coastal forest chronosequence experiment and thus serves as an important reference for future reports and publications. The report includes: information on site selection criteria, plot layout and maps; a general introduction to the ecology, physiography, geology and climate of the study area (southern Vancouver Island); and ecosystem descriptions for each site and plot including general site environment, soil descriptions, soil chemistry, general stand characteristics and lists of indicator plant species. Methods for ecosystem description are provided and results summarized and compared between subzones and among sites and seral stages. Brief summaries of each of the 18 studies of ecosystem structure, processes and diversity carried out on these sites during the first 5-year period of the experiment (1992 – 1997) are also provided. Structure studies examined differences in coarse woody debris, overstory and canopy gap distributions; process studies included investigations of changes in site carbon and nutrient levels, transformations of carbon pools, microenvironments and detrital carbon fluxes (litter fall, soil respiration and decomposition); biodiversity studies included characterization of various groups of soil fauna, carabid beetles, mycorrhizal fungi, mushrooms, salamanders, canopy lichens and vascular plants. During the first 5-year period, most of the more detailed process and diversity studies were conducted on east island Douglas-fir dominated sites. Future studies on ecosystem processes and diversity are planned for west island sites.
Chronosequence research offers scientists the opportunity to examine, over a period of a few years, long–term changes in forest succession. The knowledge gained from studies from these sites will assist foresters in improving their stewardship of these forest lands, upon which forest productivity and biodiversity ultimately depend.