摘要：Rangelands in the Hindu Kush Karakoram region provide a resource base for nomadic livestock grazing, which is one of the major traditional livelihood practices in the area. The present study assessed the spatiotemporal patterns and trends of rangelands using satellite remote-sensing time-series data. Moderate resolution imaging spectroradiometer (MODIS)-based normalized difference vegetation index (NDVI) data, collected at fortnightly intervals over 12 years (2001–2012), were used as a proxy for the vegetation conditions of the grasslands. The analysis revealed that rangeland productivity increased with increasing elevation up to the sub-alpine zone, which had a higher productivity than the moist temperate zone and humid sub-tropical zone. The high sub-alpine productivity was attributed to seasonal amplitude and the extended length of the growing season in the phenological cycle. In the temporal analysis of productivity, the majority of the area exhibited improvements in vegetation conditions, which were strongest in the humid sub-tropical zones and weakest in the alpine zones. The sub-alpine grasslands were found to be the most productive and heterogeneous habitat; however, the relatively strong negative temporal trend in productivity in this zone indicates ongoing degradation in these rangelands. Thus, special attention is needed for the sustainable management of rangelands in the sub-alpine zones of the Hindu Kush Karakoram region.
关键词：remote sensing; time-series analysis; rangelands; land degradation; Hindu Kush Karakoram
