Plant Ecology and Evolution 148(3): 301-310, doi: 10.5091/plecevo.2015.1124
Environmental filtering drives herb community composition and functional trait changes across an elevational gradient
expand article infoZihan Jiang, Keming Ma
Open Access
Background and aims – Under the assumption that ecologically similar species have similar functional traits, numerous studies have tried to use a trait-based approach to infer the abiotic and biotic factors that drive the variation in community composition. We used trait-based analyses to predict the responses in herb community composition to elevational change. We demonstrated the trait-environment relationships more precisely, and quantified the relative contribution of intraspecific variation and species replacement to shifts in community-level trait values across elevation. Methods – We measured herb community, leaf functional traits, and environmental variables along an elevational gradient at Donglingshan Mountain, China. We examined the relationships between environmental variables and functional traits and analysed the variation of functional traits along the elevational gradient. Key results – Minimum temperature (MinT) and light availability were the most important factors that shaped the herb community across elevation. Leaf hardiness and thickness were correlated strongly with MinT, while leaf mass per area, hair density, and leaf area were correlated with light availability. The trends in traits across an elevational gradient were due both to species replacement and intraspecific variation; however, the proportion of the species replacement depended on the functional traits evaluated. Conclusions – These results allowed us to identify the major functional traits and environmental factors involved in the herb community composition along the elevational gradient and demonstrate that environmental filtering (in this case MinT and light availability) is the process that shapes both herb community composition and functional traits. Moreover, we highlighted the need for greater consideration of the role that intraspecific variation plays in changes in functional traits, which can assist us in understanding herb community composition across elevations, and also in predicting its responses to climate change.