DETECTING LANDSCAPE CHANGES IN THE INTERIOR OF BRITISH-COLUMBIA FROM 1975 TO 1992 USING SATELLITE IMAGERY

To consider the regional scale effects of forest management requires c omplete and consistent data over large areas. We used Landsat Thematic Mapper and Multispectral Scanner (TM and MSS) imagery to map forest c over and detect major disturbances between 1975 and 1992 for a 4.2 x 1 0(6) ha area of interior British Columbia. Forested pixels were mapped into closed conifer, semiopen conifer, deciduous, and mixed forest cl asses, with further subdivision of the closed conifer type into three age-classes. The image-based estimate of harvested area was similar to an independent estimate from forest inventory data. Changes in landsc ape pattern from 1975 to 1992 were examined by calculating indices tha t describe overall landscape pattern and that of conifer and harvested patches in each biogeoclimatic zone. Harvesting affected 8.4% of the forest area outside provincial parks during the 17-year period. Harves ted areas were consistently much smaller than conifer patches in all b iogeoclimatic zones and had a lower percentage of interior area and pe rimeter/area ratio. Conifer patch-shape complexity varied between zone s; harvested patches had simpler shapes and were similar in all zones. Results indicate that this landscape is only in the early stages of f ragmentation, but a similar harvest pattern has been imposed on differ ing ecological zones.