Systematic review and meta-analysis reveals functional traits and climate are good predictors of tropical tree water use

Abstract

Hydrological and vegetation models, with the help of various micro-meteorological methods, are widely used to calculate water fluxes. Correctly estimating these fluxes requires accurate transpiration measurements. Tree water use is known to be influenced by many factors but there is scant literature on the factors influencing tree water use in tropical forest areas. This study presents the first systematic review of research into tree water use in the tropics. The aim of the study was to understand the research trends and the influence of tree functional traits on water use. The study found a clear bias in research focus on geographic area and species group selection. The results indicate that water use increases in tropical tree species with increased tree size, sapwood area, leaf area index, and seed mass. On the other hand, wood density is negatively correlated with tree water use. Season is highly significant in explaining variations in tree water use, as was leaf phenology. Tropical trees’ water use significantly increases during the dry season. Native trees use more water than exotic trees species. Brevi-deciduous trees uptake significantly more water than evergreen and deciduous species during the dry season. These tree traits and their relationship with water use can provide a tool for better understanding ecohydrological processes, which can support improved plantation management and conservation of water resources. This systematic review identified research gaps that, if addressed, could inform the development of hydrological and vegetation models for the efficient management of water resources.