中国生态系统GPP变化热点区域检测与归因分析

Detection and attribution analysis of hotspots of ecosystem gross primary production change in China

  • 摘要: 结合趋势分析与热点分析检测中国GPP变化的热点区域,从热点区和像元2个尺度探讨了自然和人类活动对热点区域GPP变化的影响.结果表明:1982—2017年中国GPP总体呈增加趋势,变化均值为1.92 g·m−2·a−1;GPP正向变化的热点区域位于川西高原、黄土高原、华北平原及云贵高原;GPP负向变化的热点区域位于藏南、长江三角洲和东南沿海地区;研究考虑的3个自然因子中,气温与GPP相关程度最高;以气温和人类活动为主导因素的像元比例最高,达43.86%.气温和人类活动在各热点区域的影响方向不同,总体上在GPP显著增加的4个热点区域都起到了促进作用,在GPP显著减少的3个热点区域都起到了负面影响.

     

    Abstract: Terrestrial gross primary production (GPP) is a key process for understanding land ecosystem dynamics.Detecting hotspots of GPP change and analyzing impact factors are helpful to understand ecosystem carbon cycle and provide reference for ecological environment protection and management.In the present study, trend analysis and hotspot analysis were combined to detect hotspots of GPP changes in China and to analyze the impact of natural factors and human activities on GPP changes.GPP was found to have an increasing trend from 1982-2017 in China, with an average change of 1.92 g·m−2·a−1.The hotspots with significant positive GPP change were found located in eastern Qinghai-Tibet Plateau, The Loess Plateau, North China Plain and The Yunnan-Guizhou Plateau.Hotspots with significant negative GPP change were found located in the southern part of Tibet, The Yangtze River delta and the southeast coastal areas.The combined influence of temperature, precipitation and radiation on GPP was greater than any single natural factor, correlation between temperature and GPP was the highest.The proportion of pixels with temperature and human activities as the dominant factors of GPP change was the highest, accounting for 43.86%, followed by temperature (26.86%).The influence of temperature and human activities varied in different hotspots.On the whole, they played a positive role in 4 GPP increasing hotspots and a negative role in 3 GPP decreasing hotspots.