中亚草地NPP时空动态及其驱动因素研究

Study on spatio-temporal dynamics and driving factors of NPP in Central Asian grassland

基于CASA模型和Miami模型计算中亚五国(哈萨克斯坦、塔吉克斯坦、吉尔吉斯斯坦、土库曼斯坦和乌兹别克斯坦)的草地净初级生产力(NPP),旨在探究2001—2019年中亚草地NPP的时空动态及其驱动因素。结果表明:2001—2019年中亚地区草地的实际净初级生产力(ANPP)均值为118.9 g C·m^(-2)·a^(−1);在空间尺度上,平原地区的草地ANPP随纬度增加而呈现由南到北逐渐增加的趋势,从平原到山地草地ANPP随海拔升高呈现明显的增加趋势;在时间尺度上,ANPP总体呈现不显著的增长趋势,近60%区域的草地ANPP未来的变化趋势将与过去相反,但不显著;在中亚草地ANPP增加的区域,人类活动占主导地位;在中亚草地ANPP降低的区域,气候变化是主要驱动力;中亚草地的ANPP与降水呈现显著正相关的区域达到67.8%,温度与中亚草地ANPP的变化关系不显著,降水是影响中亚草地ANPP变化的主要气候因子。

Based on the CASA and Miami models,the net primary productivity(NPP)of five Central Asian countries(Kazakhstan,Tajikistan,Kyrgyzstan,Turkmenistan,and Uzbekistan)was calculated in this study.The purpose was to explore the Spatio-temporal dynamics and driving factors of NPP in Central Asian grassland from 2001 to 2019.The results showed that the average ANPP of grassland in Central Asia from 2001 to 2019 was 118.9 g C·m^(−2)·a^(−1).On the spatial scale,the ANPP of grassland in the plain area increased gradually from south to north with increasing latitude.In contrast,the ANPP of grassland from plain to mountain grassland increased with increasing altitude.On the temporal scale,the overall growth trend of ANPP was not significant,and the future change trend of grassland ANPP in approximately 60%of the region was opposite to that of the past.The trend was not significant in the region of Central Asia with increased grassland ANPP where human activities are dominant and with decreased grassland ANPP,with climate change as the main driving force.A significant positive correlation existed between ANPP and precipitation accounting for 67.8%,with no significant relationship between temperature and the change of ANPP in Central Asian grassland.Therefore,precipitation is the main climatic factor affecting the change of ANPP in Central Asian grassland.