Many forest managers, including those involved in Ecosystem-Based Management (EBM) , are currently developing recommendations for applying variable retention and other partial cut harvesting systems without adequate field-based information about how these forests have responded to disturbance over the past century of man-caused and natural disturbances. The EBM Handbook, Central Coast Land and Resource Management Management Plan (CCLRMP) and North Coast Land and Resource Management Management Plan (NCLRMP) environmental risk assessments use ecosystem recovery rates and the distribution and abundance of second growth versus old-growth forests as a basis for Environmental Risk Assessment. And the Landscape Unit Planning Guide and Biodiversity Guidebook designate protection of old-growth forests in Old Growth Management Areas. Lack of quantitative information has necessitated the use of expert opinion to provide qualitative ecosystem recovery curves and comparisons of old-growth versus second-growth characteristics. One outcome of this is the designation of stands 250 years or older as old forest and stands less than this as younger forest, with an assumption that age class 9 stands have recovered old growthness and, e.g., age class 8 stands havent.
This project will allow us to better quantify when second-growth forests recover the attributes of old-growth forests. This will have important applications to timber supply and biodiversity. Similarly, the impacts of partial cutting/variable retention of timber supply and consequences to socio-economic well being have been estimated without sufficient on-the-ground data to support them. This information is being used in modelling of clearcutting and variable retention scenarios but it has not included sufficient detailed site-specific data from disturbed stands. More detailed information on ecosystem recovery will make modelling results more reliable and provide better guidance to planners involved in SFM and EBM efforts. Quantitative second-growth data are essential to properly evaluate and refine coarse filter biodiversity, ecological risk assessment and timber supply assumptions currently shaping EBM for Coastal LRMP's. The overall objective of this project is to quantify selected second growth coastal forest ecosystem attributes in order to provide a field-based assessment of ecosystem recovery following disturbance. This objective will be accomplished through a retrospective examination of existing coastal second growth forest stands that have developed after man-caused and natural disturbances. On the coast, these disturbances will include old A-frame and select-to-cut logging operations, aboriginal burning, and natural disturbances such as windthrow, fluvial disturbances, and landslides. The intent is to characterize the ecological condition and level of ecosystem recovery toward 'old-growth' stand conditions and the development and growth of residual stands and post-disturbance regeneration cohorts. Variables to be assessed will include tree species composition, growth and yield, understory composition, epiphytic composition, soil properties, and stand structure. The essential questions that this study will attempt to answer are: a) What old-growth structures are present in second-growth forests? b) Do different disturbances develop different structures? c) When do old-growth structures develop in second-growth forests?
This will be a two-year project. Our approach emphasises site selection and a limited amount of sampling in the first year with more extensive sampling in the second year of the project. We will sample 30 candidate second growth coastal stands in the CWHvh1 and CWH vm1 BEC units from approximately Cape Caution southwards. This will include areas of northern and western Vancouver Island, and the adjacent mainland and islands, down to approximately Barkley Sound and Loughborough Inlet. We will sample stands ranging in age from 75 to 25 ...
Negrave, Roderick W., MacKinnon, J. Andrew; Saunders, Sari. 2008. Forest Ecosystem Recovery Following Disturbance: A Retrospective Analysis of Historic Disturbances on the Southern BC Coast. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report
Topic: FLNRORD Research Program
Keywords: Forest, Investment, Account, (FIA), British, Columbia
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