The purpose of this project is to provide baseline data on second-growth structural and compositional recovery for both tree and understorey species (defined as ecosystem recovery) in riparian and upland forests. We have do not have a good understanding of the habitat potential of second-growth forests, including riparian forests, or baseline data for determining targets for restoring structural complexity and compositional diversity associated with the original old-growth forests in second-growth forests. Many of our riparian areas in coastal BC are second-growth because those forests had the most accessible, highest volumes of timber and were logged first. However, these are also the most productive forest sites so the greatest potential for ecosystem recovery, especially since they are often our oldest second-growth.
The Millennium Ecosystem Assessment, an analysis of the state of the world?s ecosystems, concluded there were virtually no baseline historical data - essential for accurately assessing conditions and trends in biodiversity. In order to determine the effectiveness of stand-level attributes for maintaining biodiversity, we need such baseline information on stand-level attributes to develop targets and management guidelines. Lyell Island (Gwaii Haanas National Park Reserve) is an ideal location for such an investigation. There is a range of seral stages (both logging dates and methods), the area will never be logged again (so can provide a long term baseline) and is being managed solely for biodiversity values. Further, many historical data sources have already been compiled. The original forest composition and riparian zone (based on terrain units) have already been reconstructed from historical sources (1937 air photos and 1966 forest cover maps) (Pearson and Gergel 2006), so a landscape-level environmental baseline already exists to which the second growth information can be linked. There are also 1966 cruise data and ecosystem plot data from the 1970s/1980s to further verify the characteristics of the original old-growth stand, including understorey species. In addition, there are old-growth structure and composition plots and gap transects from a previous wind disturbance study that can serve as a comparative baseline (Pearson et al. 2005) and second-growth growth and yield plots that were established in 1962. Finally, a stream restoration project is already underway with Haida Fisheries, Parks Canada and other agencies where the riparian forest information can be directly applied.
Based on the air photo record, logged areas will be delineated into three classes: early logging (pre-1937), logging 1937 ? 1970, logging 1971 ? 1987, stratified into riparian and upland areas. Actual data of logging will determined from second-growth tree ages in the field. Second-growth forest structure and composition will be determined from forest structure plots and gap transects following standard techniques (See experimental design and methods.) The characteristics of the original stand will be determined from the original forest composition derived from the 1937 air photos and 1966 forest cover maps, abundance and species composition of stumps and logs remaining on the ground, air photo interpretation and historical data sources (such as old-growth plot data). The accuracy of the reconstruction will be tested against old-growth information for Windy Bay, which was never logged, so can serve as test of differences between old-growth attributes on the 1937 photos and modern photos/field verification. We will focus our analyses on differences in forest structure and composition with different eras of logging. Did western redcedar successfully regenerate on pre-1937 logged areas before introduced deer were abundant? Are residual Vaccinium and other shrub species more abundant in early logging sites? What is the dead wood legacy (sizes, species, decay classes of logs and snags) in second-growth forests? Do sites that wer ...
Pearson, Audrey F.. 2008. Structural recovery in second-growth forests on Lyell Island, Haida Gwaii. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2008MR064
Topic: FLNRORD Research Program
Keywords: Forest, Investment, Account, (FIA), British, Columbia
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