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 reference 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 environmental baseline data - essential for accurately assessing conditions and trends in biodiversity over time. In order to determine the effectiveness of stand-level attributes for maintaining biodiversity, we need such baseline data 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 landscape-level data on reference conditions 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 this past summer?s field season, our experimental design was successful. Using the air photo record, logged areas were delineated into three classes: early logging (pre-1937), logging 1937 ? 1966, logging 1966 ? 1987, stratified into riparian and upland areas. Second-growth forest structure and composition were 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. These analyses will be conducted over the winter and be reported in the March 31 2008 report as well as form the basis of the first manuscript.
The key forest management issues addressed by this project are forest structural and compositional recovery following logging, in both upland and riparian forests. Our questions and analyses are thus focused on differences in forest structure and composition with differen ...
Pearson, Audrey F.. 2009. Structural recovery in second-growth forests on Lyell Island, Haida Gwaii. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2009MR427
Topic: FLNRORD Research Program
Keywords: Forest, Investment, Account, (FIA), British, Columbia
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