Human disturbances on landscapes in protected areas: a case study of the Wolong Nature Reserve

摘要

Human-induced ecological degradation in protected areas is of great concern in landscape ecological studies. Using Landsat TM data and GIS-based spatial analysis, we assessed the impacts of human disturbances on landscape structure in the Wolong Nature Reserve in southwestern China. Buffer zone and landscape dissimilarity analysis were used to examine the scope of three types of human-induced disturbances—construction of hydropower stations, human activities around settlement, and human activities along roads. We found that the impacts of these human disturbances extend to a threshold distance of about 1,000 m from the sources of disturbance. The intensity of the impact of human disturbances on landscape structure exhibited clear distance-decay effects. The first 200 m buffer zone is the area where human activities have inflicted the most visible changes, with a decrease of forest cover by 15-40% and an increase of shrub and barren land area by 15-50%. The relative intensity of the overall impact on landscape structure was highest around hydropower stations, second around human settlements, and lowest along roads. Overtime, however, the relative level of impact associated with construction of hydropower stations will likely decrease and that associated with human activities around settlements likely increase. Our case study of Wolong exposes hurdles that habitat preservation must cross in protected areas. Future management of Wolong Nature Reserve should focus on adoption of effective policies to further constrain human activities in the reserve.