2000—2021年黑龙江省植被水分利用效率的时空变化

Spatio-temporal Variation of Vegetation Water Use Efficiency in Heilongjiang Province from 2000 to 2021

水分利用效率(WUE)是衡量生态系统碳水循环耦合程度的重要指标,本文以黑龙江省为研究区,基于500 m空间分辨率的长时间序列MODIS NPP和MODIS ET数据源,计算年尺度和多年尺度的植被水分利用效率,采用M-K分析方法、EOF分析方法和GIS空间分析方法,探究了2000—2021年黑龙江省植被水分利用效率的时空变化规律,以及WUE和NPP、ET关系。研究表明:1)在时间上,WUE总体上随着时间变化呈现出增加的趋势;2)在空间上,WUE呈现了以同向分布模式为主,北—南反向分布模式为辅的特点;3)不同时间尺度WUE和NPP呈显著正相关,而其他关系存在明显的时间尺度依赖性。研究结果可为我国生态文明建设提供科学参考,有助于预测气候变化对陆地生态系统碳水过程的影响。

Water use efficiency(WUE)is an important index to measure the coupling degree of carbon and water cycle in the ecosystem.In this paper,Heilongjiang province is taken as the study area.Based on the long-time series MODIS NPP and MODIS ET data sources with 500 m spatial resolution,WUE at annual and multi-year scales are calculated.Using M-K analysis method,EOF analysis method and GIS spatial analysis method,the temporal and spatial variation law of vegetation water use efficiency and the relationship between WUE,NPP and ET in Heilongjiang province from 2000 to 2021 are explored.The results show that:(1)In terms of time,WUE shows an increasing trend over time;(2)Spatially,WUE is mainly distributed in the same direction,supplemented by the north-south reverse distribution;(3)WUE and NPP were significantly positively correlated at different time scales,while other relationships were significantly time scale dependent.The results can provide a scientific reference for the construction of ecological civilization in China,and help to predict the impact of climate change on terrestrial ecosystem carbon and water processes.