西藏草地生长季产草量动态变化及可持续发展策略

论文利用西藏地区草地产草量实际调查数据和NDVI数据集,建立西藏草地产草量估算模型,定量分析了1987—2010年间西藏草地生长季的产草量时空变化特征。研究表明：1987—2010年间,那曲地区草地产草量增速最大,增幅为54%,而拉萨地区草地产草量呈现负增长,减幅为4%。在空间分布上,总体呈现由西北向东南递增趋势;产草量增加的地区主要位于西藏中北部,南部多为产草量减少的区域。西藏草地产草量增加的区域面积占草地总面积的76.04%;产草量减少的区域面积仅占全区草地面积的23.96%。在年代际变化上,1996—2006年10 a间西藏产草量增加的区域面积显著大于减少的区域面积。为了改善西藏草地生态系统状况,进一步提高草地产草量,论文从草地开发利用、空间格局、病虫害防治和退耕还草生态补偿等方面提出西藏草地资源可持续发展策略。

The Dynamic Changes of Grass Yield during the Growing Season in Tibetan Grasslands and the Sustainable Development Strategies

Using actual survey data of grassland yield in Tibet and NDVI data sets, grass yield estimation model in Tibet was established, and then the characteristics of spatial and temporal variation of grassland yield in the grass growing season of Tibet during the period of 1987 to 2010 were analyzed quantitatively. Research showed that: during the period from 1987 to 2010, the growth rate of grassland yield in Naqu was the largest, which was 54%. However, the grassland yield in Lasa showed a decrease of 4%. Spatially, the growth of grass yield showed a trend of increase from northwest to southeast. The areas of increased grassland yield mainly located in the north-central Tibet, while in southern region there were mostly areas of grassland yield reduction. The area of grassland with increased yield accounted for 76.04% of the total grassland area. The area of grassland with reduced yield was only 23.96% of the total grassland area. The area of grassland with increased yield was significantly larger than that of grassland with reduced yield during the period from 1996 to 2006 in Tibet. In order to improve the grassland ecosystem and the grassland yield in Tibet, this article proposed a sustainable development strategy for Tibet grassland resource from the aspects of grassland utilization, spatial pattern, pest control, and ecological compensation for returning farmland to grassland.