内蒙古正蓝旗降水量对草原生产力的影响

Impacts of precipitation on grassland productivity in Zhenglan Banner,Inner Mongolia

【目的】分析内蒙古正蓝旗降水量对草原植被生产力的影响,为草原的合理规划、利用以及草原生态保护提供科学参考。【方法】基于2000-2013年正蓝旗年降水量、生长季降水量(4-8月)和不同类型草原(低地草甸、温性典型草原和温性草甸草原)生产力数据,采用回归分析的方法探讨该地区2000-2013年降水量对草原生产力的影响。【结果】1)年降水量和生长季降水量均与草原生产力呈正相关关系,且生长季降水量分别与草甸草原、典型草原和低地草甸生产力构建的回归模型相关性(R分别为0.564,0.826和0.845),略高于年降水量与上述3种类型草原生产力构建的模型(R分别为0.569,0.820和0.826),但是二者差异不显著。2)年降水量和生长季降水量对不同类型草原生产力的影响程度均不同,二者与不同类型草原生产力的相关系数均为低地草甸>典型草原>草甸草原。【结论】草原生产力的年际变化受降水量年际波动的影响,且年降水量和生长季降水量对草原生产力的影响程度并没有明显差异,但二者对典型草原和低地草甸生产力的影响均明显大于草甸草原。

【Objective】This study analyzed the impacts of precipitation on grassland productivity in Zhenglan Banner,Inner Mongolia to provide reference for the rational planning and utilization of grassland and grassland ecological protection.【Method】Using productivity of different types of grasslands（meadow steppe,typical steppe,and lowland meadow steppe）,annual precipitation and seasonal precipitation,regression analysis method was used to examine effects of precipitation on grassland productivity during 2000-2013.【Result】Both annual precipitation and seasonal precipitation were positively related to the productivity of grassland,and seasonal precipitation had slightly higher correlation coefficients with meadow steppe,typical steppe and lowland meadow steppe productivity（R=0.564,R=0.826,and R=0.845）than annual precipitation（R=0.569,R=0.820,and R=0.826）.But the difference between the two groups was not significant.The responses of grassland productivity to precipitation variables differed among various grassland types.The precipitation was less significantly related to productivity of meadow steppe compared to typical steppe and lowland meadow steppe.【Conclusion】Precipitation played an important role inchange of grassland productivity,but the influences of annual precipitation and seasonal precipitation were not significantly different.The productivity of typical steppe and lowland meadow steppe was more significantly affected by precipitation than the meadow steppe.