In the context of climate change, the functionality of ecosystems is primarily influenced by the availability of water and energy supply. However, there is limited research that comprehensively uses energy indicators to explore how climate change affects the water and energy limiting states of ecosystems. Here we evaluated the historical and future water and energy limitations using the Ecosystem Limitation Index (ELI) derived from evapotranspiration (ET), soil moisture (SM), net radiation (Rn), and air temperature (Ta), and conducted an in-depth analysis of the dominant factors. The results indicate that: (1) The degree of water limitation deepened initially and then weakened. Over 68 % of the region became drier initially, while over 83 % became wetter later. (2) In terms of area, soil moisture emerged as a critical factor influencing the variations in water and energy constraints within the Loess Plateau. Further research revealed the range of critical soil moisture (CSM) for the transition of water-energy limitation state is 0.286 mm3mm−3, and it varies with changes in temperature, soil texture, vegetation cover, and season. (3) Future projections suggest a transition towards heightened water limitations across the Loess Plateau. These findings underscore the efficacy of ELI in assessing and predicting dynamic ecosystem changes, offering valuable insights into the impacts of climate change on water and energy cycles within semi-arid ecosystems.

中文翻译：

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黄土高原土壤水分驱动生态系统水分限制变化


在气候变化的背景下，生态系统的功能主要受水和能源供应的可用性影响。然而，全面使用能源指标来探索气候变化如何影响生态系统的水和能源限制状态的研究有限。在这里，我们使用由蒸散 （ET）、土壤水分 （SM）、净辐射 （Rn） 和空气温度 （Ta） 得出的生态系统限制指数 （ELI） 评估了过去和未来的水和能源限制，并对主导因素进行了深入分析。结果表明：（1）限水程度先加深后减弱;超过 68% 的地区最初变得更干燥，而超过 83% 的地区后来变得更潮湿。（2） 从面积上看，土壤水分成为影响黄土高原水分和能源约束变化的关键因素。进一步的研究表明，水能限制状态转变的临界土壤水分 （CSM） 范围为 0.286 mm3mm−3，它随温度、土壤质地、植被覆盖和季节的变化而变化。（3） 未来的预测表明，整个黄土高原将向更高的用水限制过渡。这些发现强调了 ELI 在评估和预测动态生态系统变化方面的有效性，为气候变化对半干旱生态系统内水和能源循环的影响提供了有价值的见解。