2001~2020年中国植被NPP对气象干旱的响应特征

Response Characteristics of NPP to Meteorological Drought in China from 2001 to 2020

准确评估中国不同气候区植被净初级生产力(NPP)对气象干旱的响应特征,对于研究区域生态系统碳循环及气候变化有着重要意义。基于2001~2020年的NPP数据和构建的高分辨率标准化降水蒸散指数(SPEI)数据,采用Theil-Sen斜率估计、Mann-Kendall趋势检验和Pearson相关分析等方法解析全国不同气候区NPP和SPEI的时空变化趋势,探索各气候区NPP对不同尺度气象干旱的响应特征。结果表明,各气候区NPP对气象干旱的响应表现出明显的空间异质性,北方半干旱区和北方半湿润区大部分区域NPP与SPEI-12呈显著正相关,而西南半湿润区多呈显著负相关,同时北方半干旱区NPP与夏季SPEI-3的相关性相较于与SPEI-12的相关性更为显著;各气候区NPP均与中长期SPEI和年中月份的短期SPEI表现出较高的相关性,但因区域气候条件不同,植被对短期干旱和长期干旱的响应特征均有差异。

Evaluating the response characteristics of net primary productivity(NPP)to meteorological drought in different climatic regions of China has important meaning for studying regional ecosystem carbon cycling and climate change.Based on NPP data and the constructed high-resolution standardized precipitation evapotranspiration Index(SPEI)data from 2001 to 2020,The methods of Theil-Sen slope estimation,Mann-Kendall trend test,and Pearson correlation analysis were used to decipher the spatiotemporal variation trends of NPP and SPEI in national climatic regions.The response characteristics of NPP to meteorological drought at different scales in each climate region were discussed.The results show that the response of NPP to meteorological drought in various climate regions shows obvious spatial heterogeneity.In most areas of the northern semi-arid and northern sub-humid regions,NPP is significantly positively correlated with SPEI-12,while in most southwest semi-humid regions,there is a negative correlation.The correlation between NPP and summer SPEI-3 in the northern semi-arid area is more significant than the correlation with SPEI-12.NPP in each climatic region shows a higher correlation with medium and long-term SPEI and the short-term SPEI in the middle of the year.Due to different regional climatic conditions,the response characteristics of vegetation to short-term and long-term droughts were different.