Variation in woody leaf anatomical traits along the altitudinal gradient in Taibai Mountain, China

Abstract

As important indicators of leaf traits, leaf anatomical traits are sensitive and adaptable to environmental changes. However, how leaf anatomical traits at species and community levels vary along the altitudinal gradients is still unclear. In this study, a total of 60 woody plants from four typical vegetation zones along the 2000 m-elevation gradients in the northern slope of Taibai Mountain were selected to measure the leaf thickness (LT), epidermal thickness (ET), palisade tissue thickness (PT), spongy tissue thickness (ST), and palisade-spongy tissue thickness ratio (PST). Based on the data of the relative dominance of each species within a community, we calculated the community weighted means (CWM) of leaf traits. We aimed to investigate the variation of leaf anatomical traits at both species and community levels along the altitudinal gradients, and to explore their influencing factors. Our results showed that different elevational patterns of leaf anatomical traits occurred between the species and community levels. At the species level, LT, ET, PT, and ST increased with the altitudinal gradient, which were controlled by both of phylogenetic and environmental factors. Differently, the community-level leaf anatomical traits increased first and then decreased with elevation, and were mainly influenced by climatic factors. These results indicated that, different from species-level traits, community-level traits, which included community structure and species information, could better reflect the real plant community and their variation along the elevation. Furthermore, both of environmental factors and phylogenetic differences should be taken into account when exploring the variation in leaf anatomical traits.