内蒙古三种草地植物群落地上净初级生产力与水热条件的关系

Relationship between Aboveground Net Primary Productivity and Precipitation and Air Temperature of Three Plant Communities in Inner Mongolia Grassland

草地生产力是畜牧业发展的前提和基础,草地植物群落净初级生产力是草原生态系统中草、土、畜三个子系统及其环境综合作用的结果.对内蒙古赖草草甸、大针茅草原和红砂荒漠上15年的草地植物群落生产力及气象数据进行拟合回归分析,结果显示,红砂荒漠植物群落净初级生产力的变异系数最高,对气候变化的响应最敏感.降水量和温度在内蒙古这三种类型的草地上,都是影响植物群落初级生产力的关键因子.生长季的降水对草地植物群落初级生产力的形成起至关重要的作用,随降水量的增加,地上净初级生产力逐渐增大.在这三种不同类型的天然草地上,草地植物群落净初级生产力在夏季气温达到最大值的时候最大,以后随着气温的降低逐渐下降.

The productivity of grassland is a foundation for the development of the livestock husbandry. The aboveground net primary productivity（ANPP）is a result of the integrated effects from grasses, soil, livestock and their environments. The 15 years＇ data from Leyrnus chinesis （Trin） Tzvel. meadow, Stipa grandis P. Smirn. steppe and Oxytropis aciphylla Ledeb. desert were collected in Inner Mongolia grassland,and the relationship between ANPP and climate factors was analyzed. The results showed that the coefficient variation（CV）of ANPP in Oxytropis aciphylla Ledeb. desert was most sensitive to the climate change. Annual precipitation and air temperature are the key factors affecting the ANPP in these three type grasslands. The precipitation in the growth season played an important role in the ANPP changes, ANPP increased with the increasing of precipitation. The ANPP reached a maximum in the summer and then droped down, and declined with the air temperature.