The transpiration-to-evapotranspiration ratio(T/ET)is a crucial indicator of the carbon-water cycle and energy balance.Despite the marked seasonality of warming and greening patterns,the differential responses of T/ET...The transpiration-to-evapotranspiration ratio(T/ET)is a crucial indicator of the carbon-water cycle and energy balance.Despite the marked seasonality of warming and greening patterns,the differential responses of T/ET to environmental changes across the seasons remain unclear.To address this,we employed a model-data fusion method,integrating the Priestley–Taylor Jet Propulsion Lab model with observational datasets,to analyze the seasonal trends of T/ET in China’s terrestrial ecosystems from 1981 to 2021.The results showed that T/ET significantly increased in spring,summer,and autumn,with growth rates of 0.0018 a^(–1)(p<0.01),0.0024 a^(–1)(p<0.01),and 0.0013 a^(–1)(p<0.01),respectively,whereas the winter trends remained statistically insignificant throughout the study period.Leaf area index dynamics were identified as the primary driver of the increase in T/ET during summer,accounting for 79%of the trend.By contrast,climate change was the main contributor to the rising T/ET trends in spring and autumn,accounting for 72%and 77%of the T/ET increase,respectively.Additionally,warming is pivotal for climate-driven changes in T/ET trends.This study elucidated seasonal variations in T/ET responses to environmental factors,offering critical insights for the sustainable management of ecosystems and accurate prediction of future environmental change impacts.展开更多
基金National Natural Science Foundation of China,No.42201312,No.42301538Natural Science Foundation of Shandong Province,No.ZR2022QD118。
文摘The transpiration-to-evapotranspiration ratio(T/ET)is a crucial indicator of the carbon-water cycle and energy balance.Despite the marked seasonality of warming and greening patterns,the differential responses of T/ET to environmental changes across the seasons remain unclear.To address this,we employed a model-data fusion method,integrating the Priestley–Taylor Jet Propulsion Lab model with observational datasets,to analyze the seasonal trends of T/ET in China’s terrestrial ecosystems from 1981 to 2021.The results showed that T/ET significantly increased in spring,summer,and autumn,with growth rates of 0.0018 a^(–1)(p<0.01),0.0024 a^(–1)(p<0.01),and 0.0013 a^(–1)(p<0.01),respectively,whereas the winter trends remained statistically insignificant throughout the study period.Leaf area index dynamics were identified as the primary driver of the increase in T/ET during summer,accounting for 79%of the trend.By contrast,climate change was the main contributor to the rising T/ET trends in spring and autumn,accounting for 72%and 77%of the T/ET increase,respectively.Additionally,warming is pivotal for climate-driven changes in T/ET trends.This study elucidated seasonal variations in T/ET responses to environmental factors,offering critical insights for the sustainable management of ecosystems and accurate prediction of future environmental change impacts.
