人类活动对锡林郭勒盟草原净初级生产力的影响研究

净初级生产力是草地生态系统生产能力的体现,同时也是草地生态系统固碳能力的重要指标。论文利用MOD17A3净初级生产力数据（NPP）与气象资料,分析了2001—2010年人类活动对锡林郭勒盟草原净初级生产力的影响。研究表明：1）锡林郭勒盟草原实际净初级生产力（NPP_A）介于41.32~362.27 g C·m^-2·a^-1,均值为150.78 g C·m^-2·a^-1,有较明显的水平地带性规律,由东向西逐渐减小,草甸草原最大,典型草原次之,荒漠草原最小;2）锡林郭勒盟草原人类活动影响的净初级生产力（NPP_H）介于-185.07~153.92 g C·m^-2·a^-1,均值为-34.80 g C·m^-2·a^-1,人类活动负作用占草原总面积的93.4%,人类活动正作用仅占6.6%;3）人类活动对锡林郭勒盟草原净初级生产力的影响主要是由负作用向正作用转变,且空间分布有明显的南北界线,南部表现为负作用增强,北部为正作用增强。研究可为锡林郭勒盟草地资源的管理和可持续利用提供参考依据。

Effects of Human Activities on Net Primary Productivityin the Xilingol Grassland

Net primary productivity is a key index of production capacity of grassland ecosystem, and is also an important indicator of carbon fixation of ecosystem. With MODIS MOD17A3 net primary productivity (NPP) data and meteorological data, we analyzed the effects of human activities on NPP in the Xilingol grassland from 2001 to 2010. NPP_A (actual NPP) was influenced by both climate change and human activities. NPP_A was mainly in the range of 41.32-362.27 g C·m^-2·a^-1 with average value of 150.78 g C·m^-2·a^-1, and showed horizontal zonal feature gradually decreasing from east to west. NPP_A in the meadow steppe was the highest, followed by that in typical steppe, while NPP_A in the desert steppe was the lowest. NPP_H (NPP affected by human activities) was mainly in the range of -185.07- 153.92 g C·m^-2·a^-1 with average value of -34.80 g C·m^-2·a^-1 in the Xilingol grassland. Human activities had negative effects on 93.4% of the study area, and had positive effects on only 6.6% of the area. However, the impact of human activities on NPP is changing from negative effect to positive effect in most of the area. There is a boundary between the southern and the northern Xilingol grassland. The negative effect is strengthening in the southern area, while the positive effect is strengthening in the northern area. The study provided references for the management and sustainable utilization of grassland resources in the Xilingol.