Leaf and stem trait variation and plant functional types in 113 woody species of a seasonally dry tropical forest

Abstract

In seasonally dry tropical forest (SDTF) plant trait variation has been associated with adaptation to light and water availability and a coordinated tolerance of plants to shortage of both resources has been proposed. We tested this hypothesis in a set of 113 species by analyzing the relationships amongst eleven leaf and stem traits that have been related to shade and drought tolerance. In addition, the usefulness of different types of functional classifications describing community plant trait variation was evaluated. Strong relationships were observed between leaf and stem traits, potentially conferring coordinated tolerance to shade and drought, and three axes of variation were identified by means of a principal component analysis. The first axis described leaf and stem economy, the second was related to leaf thickness and organization and the third was related to the trade-offs between leaf size, stem density and bark thickness. Stem density was correlated strongly with several plant traits, emphasizing its key role in explaining variation in life history strategies of SDTF species. Significant differences were found between functional groups categorized by phylogeny and leaf phenology, whereas for life forms differences were only observed for palms and bamboos.

Keywords

• resource use strategies, trade-offs, drought, phenology, phylogenetic group, life form