为揭示新疆不同时空格局下气候因素变化对植被生产力的影响,探讨草地植被生产力与气候因子的相关关系,采用20002014年8月MOD13A1遥感数据集,利用CASA模型分析新疆草地植被净初级生产力的空间格局及动态变化,结合降水量、温度数据分析新疆不同草地植被类型NPP的变化趋势,并对其与气象因子的相关关系进行分析。结果表明: (1)从空间上,草地植被NPP各年呈北高南低的空间格局,不同的草地类型的NPP也存在较大差异,总体大致表现为草甸>高山亚高山草甸>平原草地>高山亚高山草地>荒漠草地。(2)从时间上, 2000-2014年,草地植被NPP总体呈波动式下降趋势,在2006年、2012年、2014年降到谷底,分别为50.520 g C·(m~2·a)~(-1)、54.438 g C·(m~2·a)~(-1)、54.213 g C·(m~2·a)~(-1)。(3)新疆草地植被NPP与降水呈显著正相关,与温度呈不显著负相关。表明降水是影响该地区植被NPP的主要气候因子。
英文摘要:
In order to reveal effects of climate change on grassland productivity under different spatial and temporal patterns in Xinjiang, this paper explored the relationships between productivity of grassland and climate factors. It analyzed the spatial distribution of vegetation net primary production (NPP) calculated by the Carnegie-Ames-Stanford Approach (CASA) model with MOD13A1 data in August from 2000 to 2014. And it discussed the trends of the NPP of different grassland vegetation types and correlation analysis between the trends and the temperature-precipitation data. The results are as follows. (1) In terms of spatial aspect, the grassland NPP gradually reduced from north to south. And there were also big differences in various grassland types of NPP: meadow> alpine and sub-alpine meadow> plain grassland> alpine and sub-alpine grassland> desert grassland. (2) In terms of temporal aspect, the grassland NPP gradually reduced from 2000 to 2014. And NPP came to the bottom in 2006, 2012 and 2014 with the values of 50.520 g C·(m~2·a)~(-1), 54.438 g C·(m~2·a)~(-1), 54.213 g C·(m~2·a)~(-1) individually.(3) Grassland NPP in Xinjiang was positively correlated with precipitation and had unremarkable negative correlation with temperature. It can be concluded that precipitation is the dominant climatic factor affecting vegetation NPP in the study region.