中国亚热带极端降水时空演变及其对潜在净初级生产力的影响  

Spatiotemporal variations of subtropical extreme precipitation and its influence on potential net primary productivity in China

作　　者：陈琦 毛方杰 杜华强[1,2,3] 李雪建 尹世燕[1,2,3] 闫梦洁 CHEN Qi;MAO Fang-jie;DU Hua-qiang;LI Xue-jian;YIN Shi-yan;YAN Meng-jie(State Key Laboratory of Subtropical Silviculture,Zhejiang A&F University,Hangzhou 311300,China;Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration of Zhejiang Province,Zhejiang A&F University,Hangzhou 311300,China;School of Environmental and Resources Science,Zhejiang A&F University,Hangzhou 311300,China)

机构地区：[1]亚热带森林培育国家重点实验室,杭州311300 [2]浙江省森林生态系统碳循环与固碳减排重点实验室,杭州311300 [3]浙江农林大学环境与资源学院,杭州311300

出　　处：《生态学杂志》2022年第11期2117-2127,共11页Chinese Journal of Ecology

基　　金：国家自然科学基金(31901310、32171785、31670644和U1809208);亚热带森林培育国家重点实验室开放基金(zy20180201);浙江省竹材资源高效利用协同创新中心开放基金(2017SY04);浙江农林大学科研发展基金项目(2017FR042)资助。

摘　　要：亚热带植被具有强大的固碳潜力,然而由气候变化导致的极端天气,特别是日益增多的极端降水事件,对其碳循环产生了巨大的影响。本研究基于1 km栅格气象数据计算了持续干期(CDD)、持续湿期(CWD)、日最大降水量(Rx1day)、连续5日最大降水量(Rx5day)、强降水量(R95p)和年总降水量(PRCPTOT)6个极端降水指数,分析了1970—2019年极端降水时空演变特征和亚热带植被净初级生产力(NPP)的时空格局,并探讨极端降水对植被NPP的影响。结果表明:除CWD外,其他指数均呈增加趋势,呈现降雨极端异常值增多、干旱化不显著的趋势;空间分布上越靠近西北方向越干旱,越往东南方向越湿润,空间变异特征显著;中国亚热带植被NPP以5.8 g C·m^(-2)·10 a^(-1)的速率增加;年均NPP空间分布上由东南向西北递减,空间变异整体较小;植被NPP与极端降水量指数、CWD之间以正相关为主,与CDD以负相关为主;植被NPP对CWD的变化最敏感,对CDD敏感性的空间变异最大,并且持续干期越长、极端降水量越多的地方,NPP对极端降水的敏感性越高,而持续湿期越长的地方,NPP对其敏感性越低。研究结果将为评估亚热带地区极端天气及其对植被NPP的影响提供理论支持,为理解亚热带植被响应气候变化提供重要数据支持。Subtropical vegetation has strong carbon sequestration potential, and its carbon cycle is greatly affected by extreme weather caused by climate change, especially the increasing number of extreme precipitation events. In this study, we calculated six extreme precipitation indices, including continuous dry duration(CDD), continuous wet duration(CWD), maximum consecutive 1-day precipitation(Rx1 day), maximum consecutive 5-day precipitation(Rx5 day), heavy precipitation(R95 p), and annual total precipitation(PRCPTOT), based on the 1 km grid meteorological data. We analyzed the spatiotemporal variations of extreme precipitation and net primary productivity(NPP) of subtropical vegetation from 1970 to 2019, and explored the effects of extreme precipitation on vegetation NPP. The results showed that all indices except CWD showed an increasing trend, with a trend of increasing extreme rainfall abnormal events and insignificant aridification. There were significant spatial variations of rainfall. The closer to the northwest, the drier it was, and the wetter it was to the southeast. NPP of subtropical vegetation in China increased at a rate of 5.8 g C·m^(-2)·10 a^(-). The spatial distribution of mean annual NPP decreased from southeast to northwest, and the overall spatial variation was small. NPP was mainly positively correlated with extreme precipitation index and CWD, and negatively correlated with CDD. NPP was most sensitive to the change of CWD. The spatial variation of sensitivity to CDD was the largest. The longer the dry period and the more extreme precipitation, the higher sensitivity of NPP to extreme precipitation, while the longer the wet period, the lower the sensitivity of NPP to it. The results will provide theoretical support for the evaluation of extreme weather and its impacts on NPP in subtropical regions, and important data support for understanding response of subtropical vegetation to climate change.

关 键 词：亚热带 极端降水 净初级生产力 时空演变 

分 类 号：Q948[生物学—植物学]