| Popis: |
Understanding the spatio-temporal variations of gross primary productivity (GPP) of terrestrial ecosystem and its relationship with climatic factors can provide important basis for vegetation restoration and protection. Based on meteorological data and three public GPP datasets (EC-LUE GPP, GLASS GPP, and NIRv GPP), we syste-matically analyzed the spatial-temporal variations of GPP and its response to climate change in China during 1982-2017. All the results based on the three GPP datasets showed that the annual and seasonal GPP in China increased annually from 1982 to 2017, with that in 1998 and 2002 significantly being higher than the average level during the study period, and that in 1989 and 1992 significantly being lower than the average annual GPP. From 1982 to 2017, GPP showed a significant upward trend in most regions of China, with the regions with significant increases accounting for 75.7%, 73.0%, and 69.6% of the whole study area, respectively. There was a significant positive correlation between annual GPP and precipitation and temperature, but spatial heterogeneity was strong. Among them, the regions with positive correlation between GPP and temperature were mainly distributed in Northwest and Central China, while the regions with positive correlation between GPP and precipitation were mainly distributed in North China. There was obvious spatial-temporal heterogeneity in regions that GPP being affected by temperature and precipitation in different seasons. Temperature was the limiting factor of GPP in spring, autumn and winter, while summer GPP was mainly affected by precipitation.了解陆地生态系统总初级生产力(GPP)时空变化及其与气候因子的关系,可以为植被恢复及保护提供重要依据。基于气象数据和3套公开的GPP数据集(EC-LUE GPP、GLASS GPP和NIRv GPP),本研究系统分析了中国1982—2017年GPP的时空变化特征及其对气候变化的响应。结果表明: 3套GPP数据均表明,1982—2017年,中国年和季节的GPP呈逐年上升趋势,1998和2002年明显高于研究期间的平均水平,1989和1992年明显低于多年平均GPP。1982—2017年,中国大部分地区GPP呈显著上升趋势,3套GPP数据显著增加的区域分别占整个研究区的75.7%、73.0%和69.6%。年GPP与降水和温度均存在显著正相关关系,但空间异质性较强。其中GPP与温度呈正相关的区域主要分布在西北和华中地区,GPP与降水呈正相关的区域主要分布在华北地区。不同季节的GPP受气温、降水影响的区域存在明显的时空异质性。温度是春、秋和冬季GPP的限制因子,而夏季GPP主要受降水影响。. |
