In the past decade the issue of carbon (C) stocks and sequestration in forests has become an important management consideration and will be increasingly important for countries such as Canada with large forested landbases and Kyoto Protocol involvements. Managers of forested areas are already faced with a large number of economic, environmental and cultural based objectives for those areas under their jurisdiction. In many instances, management for C sequestration can be in direct opposition to management for other objectives. For this reason, specific knowledge of the impacts of forest management on C stocks and sequestration is a key requirement for integration of this consideration in forest management.; A series of Landsat Thematic Mapper imagery was obtained for the Aleza Lake Research Forest (ALRF) from 1985 to 2003. Relative radiometric correction techniques were conducted on the set of Landsat imagery. Each radiometric correction technique was assessed using edge detection and comparisons of the output to expected vegetation patterns such as equilibrium in old-growth forest radiance and linear increases in normalized difference vegetation index (NDVI) values over regenerating clearcuts.; Biomass and woody debris C stocks measured in 2003, 2004 and 2005 were related through regression analysis to 2003 Landsat TM image data as well as spatially-explicit forest cover data. Two models were developed, a biomass C regression model and a woody debris carbon regression model, and from these a series of eight spatial datasets detailing C stocks from 1985 to 2003 was created. Landscape level estimates of C stocks were analyzed from these datasets after performing Monte Carlo uncertainty analysis on model estimates and determining effective sample sizes through spatial autocorrelation analysis.; In 2003, the total C stock in biomass and woody debris over the 5,992 ha area was 588 +/- 7 and 77 +/- 2 kt, respectively. During the time period from 1992 to 2003 clearcutting operations accounted for a C loss of 39.9 +/- 2.6 kt, while remaining areas accounted for a C gain of 31.3 +/- 10.3 kt. In total the net change over this time period was a C loss of 8.7 +/- 10.6 kt. The magnitude of the change in biomass and woody debris carbon stocks over this time period was smaller than the associated uncertainty even though the uncertainty was only approximately 1.6% of the total (666 kt), indicating that forest management in the research forest has balanced the losses of carbon associated with harvesting with the gains of carbon associated with forest growth.
展开▼
