[Edge effects of forest landscape in upper reaches of Minjiang River].

By using GIS and RS techniques, the edge effects of forest landscape in the upper reaches of Minjiang River, Sichuan Province of China were studied on landscape scale. The results showed that there was a distinct boundary between forestland and farmland, with the vegetation changed significantly. The biomass at forestland edge was lower than that in forestland interior, with the edge effect width being 60 m, whereas the biomass in farmland exterior was higher than that in farmland interior, with the edge effect width being 60-90 m. Forestland-grassland boundary was naturally formed and changed gradually. The biomass at forestland edge was lower than that in forestland interior, while that at grassland edge was higher than that in grassland interior, with the edge effect being 60 m for forestland and 45-75 m for grassland. The edge effect of forestland-shrub land boundary was similar to that of forestland-grassland boundary, with the edge effect width being 60 m for forestland and 45-75 m for shrub land.