Interspecies variation in plant surface water storage capacity in alpine meadows: Prediction based on plant ecological strategies

Abstract

Rainfall interception by vegetation is essential in precipitation redistribution within ecosystems and greatly affects water services. However, the patterns of interspecies variation in plant surface water storage (PWS) remain unclear, which greatly limits our understanding of the relationship between species composition and vegetation rainfall interception. Thus, we aimed to examine whether the plant ecological strategy, which is an internal driving force and comprehensive characteristic of plant traits, can serve as a PWS predictor. The PWS of thirty-nine common plant species in natural, degraded, and restored alpine meadows within the Ruoergai wetland was compared, and the variability in PWS between these species was examined from both plant trait and ecological strategy perspectives. The results showed that PWS per plant (IWSC) ranged from 0.12 to 9.32 mL plant−1, and PWS based on projected area (PSCI) and fresh weight (PMS) ranged from 0.01 to 0.94 mm and 0.11 to 1.29 g g−1, respectively. The PSCI was comparatively lower in Cyperaceae, whereas the PMS was relatively lower in Polygonaceae, and Poaceae. The correlations between PWS and multidimensional plant traits are complex for predicting PWS but can be clarified by considering plant ecological strategies. Further regression analysis revealed that as an evolutionary representation of the crucially related plant traits, plant competition significantly positively affected both IWSC and PSCI, and stress tolerance obviously negatively affected these two parameters (P < 0.05). The correlation between plant strategy and PSCI implied that the increased dominance of competitive species in alpine meadows may intensify interception loss, thereby hindering rainfall allocation to soil and exacerbating water scarcity.