Coupled vegetation-climate dominates the evapotranspiration variability of Forest Protection Project

Abstract

Study region: The Natural Forest Protection Project area in China (NFPP). Study focus: Applying the Pattern-Process-Mechanism theory, we analyzed the spatiotemporal differentiation pattern and change trend of evapotranspiration (ET) in NFPP from 2000 to 2018. We employed methods such as geographical detectors and path analysis to identify the dominant factors and response mechanisms of ET changes in NFPP, specifically those resulting from vegetation recovery and climate change. New hydrological insights for the region: Our study reveals that ET in NFPP exhibits a fluctuating increasing trend, rising from 299.155 mm/yr in 2000–336.805 mm/yr in 2018, with an annual average of 316.486 mm/yr and a change rate of 2.092 mm/yr. The proportion of areas with decreasing ET trend in NFPP (50.944%) is approximately equal to that of areas with increasing ET trend (49.056%). Vegetation restoration (18.959%), water conditions (18.460%), and thermal conditions (56.526%) are the predominant factors that influence the changes and distribution of ET in NFPP. However, the trend of ET and its dominant factors vary by region. We emphasize that, given the circumstances of climate change and the continued increase in ET, future vegetation recovery strategies must consider water usage, as this has critical practical implications for the sustained maintenance of regional ecological engineering outcomes.

Keywords

• Climate change
• Evapotranspiration
• Forest ecological management
• Forest Protection Project
• Vegetation restoration