云贵高原植被净初级生产力(NPP)时空格局动态变化

Dynamic Change of Spatial and Temporal Pattern of Vegetation NPP in Yungui Plateau

云贵高原是长江上中游和珠江上游等河流的生态保护源区,是重要的生态屏障区。基于MOD17A3年均NPP数据,利用GIS空间分析技术和数理统计方法研究了云贵高原植被NPP的时空格局动态变化。结果表明,云贵高原植被年均NPP总体上呈现出其西南部最高、东北部较少、中部最少的分布特点,尤其是贵州部分区域年均植被NPP较低。不同土地利用类型地区植被NPP存在明显差异,由高到低依次为林地、草地、农作物与自然植被镶嵌体、永久湿地、农作物及灌丛等。近15年间植被NPP略有减少,云贵高原年均植被NPP为767g/m^2·a;NPP绝大部分集中在716~833g/m^2·a之间,所占比例约为70%~85%;植被NPP在西南部和南部地区明显减少,在北部和中部明显增加。云贵高原大部分地区年NPP呈现增长趋势,但呈退化趋势的区域NPP减小值较大。

The Yunnan-Guizhou Plateau is an ecological protection area for the upper and middle reaches of the Yangtze River and the Pearl River. It is an important ecological barrier area. Based on annual NPP data of MOD17 A3,the spatial and temporal cahnges of vegetation NPP in Yunnan-Guizhou Plateau were studied by means of GIS spatial analysis and mathematical statistics. The results show that the annual average NPP of Yunnan-Guizhou Plateau shows its highest value is in the southwest,the less is in the northeast,while the least is in the central part. In particular,the average annual NPP in Guizhou was low. There are significant differences in vegetation NPP among different land use types,from high to low in order of forest land,grassland,mosaic land between agricultural crops and natural vegetation,wetlands,crop land and shrub. The vegetation NPP decreased slightly in the recent 15 years,and the average annual NPP was 767 g/m^2·a. The NPP values are mostly concentrated in the range from 716 g/m^2·a to 833 g/m^2·a,accounting for about 70% ~ 85%. Vegetation NPP decreased significantly in the southwestern and southern regions and increases significantly in the northern and central regions.The annual NPP showed an increase trend in most areas of Yunnan-Guizhou Plateau,but the decrease trend of NPP in the region of degradation was larger.