Trends in vegetation and their responses to climate and topography in northwest Guangxi
The annual dynamics and spatial variability of vegetation in northwest Guangxi were studied based on the SPOT NDVI datasets during 1999-2010.The response of vegetation to climate and topography was analyzed.The results showed that:(1) Vegetation had a large proportion of increasing trends in northwest Guangxi from 1999 to 2010.Partial correlation analysis between NDVI and climate parameters showed that climate had little effect on vegetation.(2) Elevation affected vegetation trend.It increased between 200 and 500 m,however,there were a small areas between 400 m and 500 m where vegetation decreased.Vegetation tended to be stable as the elevation increasing.(3) Vegetation recuperated on slopes between 6°and 15°,but decreased on slopes between 2°and 6° and above 25 °.(4) The differences of vegetation restoration on aspects were not obvious.However,vegetation recovery trended to be decreasing as the aspect turning from shady to sunny slopes.Our study indicated that the implementation of environmental conservation policies and ecological construction had resulted in the improvement of vegetation in karst regions.However,there were some regions with vegetation degradation caused by human disturbance.In the further implementation of ecological restoration,the government should pay more attention to the sunny regions where the elevation between 400m and 500m and the steep slope that larger than 25°.
SPOT-VGT NDVIclimate changecorrection coefficient for topographic areasecological construction projectskarst
国家科技期刊平台
NSTL
万方数据
维普
