Session Information
| Session | Poster Session | | Date | Monday (2008-04-07) | | Time | 5:00 PM - 7:00 PM | | Room | Grand Terrace |
Presentation Information
| Presenter | Sari Saunders | | Title | Dynamics of structure and composition in an old growth temperate rainforest stand, Southwest British Columbia | | Affiliation | BC Ministry of Forests and Range | | Authors | Sari Saunders, Andy MacKinnon, Paul Alaback | | Keywords | Coastal western hemlock, Old growth, Permanent plots, Stand structure | | Presentation Type | Poster | Abstract:
Coastal temperate rainforests span broad gradients of temperature, moisture, and continentality. Foundational studies on old growth dynamics have been conducted in southeast Alaska (e.g., Alaback and Juday, 1989) and in southern BC (e.g., Lertzman et al., 1996) and WA (e.g., Spies and Franklin, 1996). However, there has been little coordination of data collection or analysis, and no formal assessment of old growth characteristics across the coastal biome. We are establishing new, and remeasuring historic, stand-level (1 ha) permanent plots in old growth, coastal BC forests across five biogeoclimatic variants. The plot network will contribute to empirical, benchmark studies of these ecosystems and provide the baseline for long-term monitoring and research. In 2007, we remeasured a plot that was initially established in1992 within a riparian Sitka spruce (Picea sitchensis) ecosystem on southwestern Vancouver Island. We then expanded the plot to 1 ha based on national (EMAN) standards. All trees, snags, and cwd were individually marked and mapped with laser criterion, relative to GPS-referenced locations, for development of digital stand maps. Attributes recorded included species, height, dbh, and vigour for all pieces. Over 800 features were entered into the maps. Density and size and height distributions of live and dead wood differ distinctly between this and a second 1 ha plot established in hypermaritime cedar-hemlock forest, which had >800 live trees. Results also indicated the longevity of priority gaps maintained by shrubs (Rubus) over the 15 yr measurement interval, recruitment to the cwd pool, and live biomass accumulation of these forests. The reconciliation of historic and modern maps illustrated challenges of evolving technology for mapping and documenting spatial patterns and structure. Over subsequent measurement periods, these plots will contribute to parameterization of models of structure and dynamics among forest ecosystems, and to management that attempts to retain old growth characteristics within managed stands and adequate representation of old growth across a larger landscape. |
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