Assessment of ActualEvapotranspiration Variability in Response to Vegetation Types along a Precipitation Gradient

Banihashemi, Elham; Tahmasebi, Pejman; Ghehsare, Elham; Abdollahi, Khodayar

doi:10.22059/ije.2026.397981.1877

Assessment of ActualEvapotranspiration Variability in Response to Vegetation Types along a Precipitation Gradient

Articles in Press

Document Type : Research Article

Authors

¹ Faculty of Natural Resources, University of Shahrekord, Shahrekord, Iran

² Department of Rangeland Ecology, Range and Watershed Management, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran

³ Department of Rangeland Sciences, Range and Watershed Management, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran

⁴ Department Water Engineering , Range and Watershed Management, Faculty of Natural Resources and Earth Sciences, Shahrekord University, Shahrekord, Iran

10.22059/ije.2026.397981.1877

Abstract

Evapotranspiration (ET) is a key component of the hydrological cycle, influenced by various climatic and biotic factors. This study aimed to assess the impact of different vegetation types on ET along a precipitation gradient in steppe and semi-steppe regions of Chaharmahal and Bakhtiari and Isfahan provinces. Data were obtained from five rangeland sites with varying rainfall regimes and analyzed using the General Linear Model (GLM). Results indicated that the precipitation gradient had a significant and dominant effect on ET (p < 0.001), while the independent effect of vegetation growth forms was not significant in most cases. However, the interaction between vegetation type and precipitation was statistically significant for certain plant groups such as perennial grasses and shrubs (p < 0.05). Pearson correlation analysis also revealed a strong and positive relationship between vegetation cover and ET, especially for perennial grasses (r = 0.788) and total plant cover (r = 0.957). These findings suggest that more humid regions with denser vegetation exhibited higher ET, whereas in drier areas, limited water availability reduced vegetation cover and consequently decreased ET. Overall, the results underscore the crucial role of precipitation gradients in shaping vegetation patterns and evapotranspiration dynamics in rangeland ecosystems.

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