气候变化显著影响陆地生态系统生产力以及水分利用格局,而水分利用效率(Water Use Efficiency,WUE)是衡量生态系统碳水耦合关系的重要指标之一。研究陆地生态系统水分利用效率对气候变化的响应,有助于深入理解生态系统的变化规律,模拟和预测生态系统碳水过程的发展状况,从而为应对全球气候变化提供新的依据。为了更好地掌握生态系统水分利用效率研究现状以及其对温度、CO_2等关键气候因子的响应情况,总结了陆地生态系统水分利用效率对气候变化响应的最新研究进展。介绍了相关的定义并归纳了两种不同计算方式的差异和特点;总结了陆地生态系统水分利用效率对大气温度、CO_2、水分、干旱以及太阳辐射等影响因素的响应;总结了目前3个相关的研究态势,主要包括:①长时间序列水分利用效率与气候要素的关系研究;②土地利用/覆被变化对水分利用效率的影响及其对气候的反馈研究;③多尺度水分利用效率综合研究。研究可为深入研究生态系统过程对气候变化的响应提供参考。
英文摘要:
Climate change has a considerable impact on the productivity and water use of terrestrial ecosystems.Water use efficiency (WUE) is an important indicator to measure the tradeoff between carbon gain and water loss of terrestrial ecosystems.Studying the responses of terrestrial ecosystem WUE to climate change will help us understand the mechanism of ecosystem changes,simulate and predict the development of the ecosystem water and carbon balance,and provide a new basis for adapting to global climate change.To better understand the status of ecosystem WUE and the responses of WUE to key climate factors,such as temperature and CO_2 concentration,this study reviewed the current status and progress of the responses of terrestrial ecosystem WUE to climate change.Firstly,definitions of WUE were introduced and the differences as well as characteristics of two WUE calculation methods were summarized.Then,the responses of terrestrial ecosystem WUE to climate factors,such as temperature,CO_2 concentration,humidity,drought stress,and radiance,were elaborated.Finally,the three current research directions of WUE development were forecasted,mainly including:① the relationships between the long-term WUE and climate factors;② the impact of land-use and land-cover change on WUE and its feedback on climate;and ③ comprehensive research of multi-scale WUE.This study can provide a reference for studying the responses of terrestrial ecosystems to climate change.