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Chinese Journal of Applied Ecology ›› 2025, Vol. 36 ›› Issue (11): 3408-3418.doi: 10.13287/j.1001-9332.202511.021

• Original Articles • Previous Articles     Next Articles

Spatiotemporal variations and driving factors of the transpiration-to-evapotranspiration ratio in different ecosystems of Northeast China

WANG Jingli1, ZHANG Yongsheng1,2,3, YU Wenying2,3,4,5*, CAI Fu2,3,4, CHEN Nina2,3,4, YAN Guofeng1,2,3, ZHAO Yijin6   

  1. 1School of Transportation and Geomatics Engineering, Shen-yang Jianzhu University, Shenyang 110168, China;
    2Institute of Atmospheric Environment, China Meteorological Administration, Shenyang 110166, China;
    3Shenyang Institute of Agricultural and Ecological Meteorology, Chinese Academy of Meteorological Sciences, Shenyang 110166, China;
    4Liaoning Province Key Laboratory of Agrometeorological Disasters, Shenyang 110166, China;
    5Panjin National Climate Observatory, Panjin 124010, Liaoning, China;
    6Liaoyang Natural Resources Affairs Service Center, Liaoyang 111010, Liaoning, China
  • Received:2025-03-25 Accepted:2025-08-28 Online:2025-11-18 Published:2025-12-15

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Abstract: The transpiration-to-evapotranspiration ratio (T/ET) characterizes the proportion of vegetation transpiration in evapotranspiration and is of great significance for understanding the role of vegetation transpiration in ecosystem water cycling. We utilized multi-source data to analyze the variations and driving factors of T/ET in three ecosystem types of Northeast China from 2001 to 2020, including forests, croplands, and wetlands. The results showed that the interannual variation of T/ET in forests, croplands, and wetlands exhibited a slight upward trend from 2001 to 2020, with annual increase rates of 0.0006, 0.0037, and 0.0009, respectively. T/ET exhibited a unimodal pattern during the growing season, rising from May, peaking in July and August, and then declining. The proportions of areas showing an upward trend in T/ET in forest, cropland, and wetland ecosystems were 59.7%, 84.7%, and 55.1%, respectively. During the growing season, the T/ET ratios of forest ecosystems in the southeastern part of the study area, cropland ecosystems in the central part, and wetland ecosystems in the southern part were all higher than those of the same ecosystem type in other regions. The dominant biological driving factors for T/ET changes in the three ecosystem types were gross primary productivity (GPP) and solar-induced chlorophyll fluorescence, but with differences among different ecosystems. In forest ecosystems, the explanatory power of relative humidity, precipitation, and minimum temperature was higher than that of other environmental factors. In croplands, the effects of saturation vapor pressure deficit, relative humidity, and precipitation were more significant. In wetlands, T/ET was mainly influenced by net radiation, precipitation, and minimum temperature. Among the combinations of biological and environmental factors influencing the changes in T/ET across different ecosystems, gross primary productivity and relative humidity constituted the most explanatory combination.

Key words: transpiration-to-evapotranspiration ratio, gross primary productivity, solar-induced chlorophyll fluorescence, optimal parameters-based geographical detector