摘要
水分利用效率(WUE)是评估一个生态系统新陈代谢与固碳能力的重要参数,也是衡量陆地生态系统碳循环和水循环耦合程度的关键指标,研究其时空变化及对气候变化的响应具有重要意义。本研究基于MODIS数据、气象观测数据和植被类型数据,定量估算2002—2022年伊犁河谷各类型草地WUE时空变化特征,并采用趋势分析和偏相关分析探究河谷草地WUE变化趋势及其对气温、降水量的阈值效应。结果表明:1)伊犁河谷草地多年平均WUE为1.48 gC/(mm·m^(2)),总体呈微弱降低趋势。其中典型草原WUE最高,其次为荒漠草原、草甸草原、典型草甸和高寒草甸。2)在空间上,WUE总体呈中部高,并向南北两端逐渐降低的分异规律,其分布格局与海拔总体呈负相关关系。3)河谷WUE与年气温多呈正相关,与气温不同,降水与河谷草地WUE基本呈负相关关系。具体来说,典型草甸、荒漠草原和高寒草甸WUE与气温呈正相关关系,各类草地中仅有典型草甸与降水为正相关。4)草甸草原、高寒草甸、典型草甸、典型草原和荒漠草原生长的最佳气温阈值为-6~0℃、-8~2℃、-6~2℃、4~8℃和-4~6℃,其降水最佳阈值分别为650~800 mm、550~800 mm、500~800 mm、400~600 mm和400~550 mm。
Water use efficiency(WUE)is an important parameter to evaluate the metabolism and carbon sequestration capacity of an ecosystem,and also a key index to measure the coupling degree of carbon cycle and water cycle in terrestrial ecosystems,it is great significance to study the spatiotemporal variation of WUE and its response to climate change.Based on MODIS data,meteorological observation data and vegetation type data,this study quantitatively estimated the spatio-temporal variation characteristics of WUE across various grassland types in Ili River Valley from 2002 to 2022,and used trend analysis and partial correlation analysis to explore the variation trend of WUE of grassland in the valley and its threshold effects on temperature and precipitation.The results showed as follows:1)The annual average WUE in the valley grassland of Ili River was 1.48 gC/(mm·m^(2)),which showed a slight decreasing trend in general.The WUE of typical steppe was the highest,followed by desert steppe,meadow steppe,typical meadow and alpine meadow.2)In terms of space,WUE is generally high in the middle,and gradually decreases to the north and south,and its distribution pattern is negatively correlated with altitude.3)WUE in valley was positively correlated with annual air temperature,while precipitation was negatively correlated with WUE in valley grassland.Specifically,WUE of typical meadows,desert steppe and alpine steppe was positively correlated with temperature,and only typical meadow was positively correlated with precipitation among all kinds of grasslands.4)The optimal temperature thresholds for growth of meadow steppe,alpine meadow,typical meadow,typical steppe and desert steppe were-6~0℃,-8~2℃,-6~2℃,4~8℃and-4~6℃.The optimal precipitation thresholds are 650~800 mm,550~800 mm,500~800 mm,400~600 mm and 400~550 mm,respectively.
作者
张发
祝小梅
张红
塔依尔·艾则孜
伊尼特扎尔·加帕尔
唐玉强
马艳艳
ZHANG Fa;ZHU Xiao-mei;ZHANG Hong;Tayir·Aziz;Yinitezhaer·Jiapaer;TANG Yu-qiang;MA Yan-yan(Huocheng County Meteorological Bureau,Huocheng 835200,China;Meteorological Bureau of Ili Hask Autonomous Prefecture,Yili 835000,China)
出处
《环境生态学》
2024年第4期57-64,共8页
Environmental Ecology
基金
新疆气象科技创新发展指导性基金项目(MS202218)
新疆气象局引导性计划项目(YD202218)
基于MODIS的伊犁河谷水分利用效率时空特征分析(KT-202302)资助。
