Divergence in functional traits in seven species of neotropical palms of different forest strata

Abstract

Abstract Functional traits are morphological and physiological characteristics that determine growth, reproduction, and survival strategies. The leaf economics spectrum proposes two opposing life history strategies: species with an "acquisitive" strategy grow fast and exploit high-resource environments, while species with a "conservative" strategy emphasize survival and slow growth under low resource conditions. We analyzed interspecific variation in nine functional traits related to biomass allocation and tissue quality in seven Neotropical palm species from three forest strata (understory, subcanopy, and canopy). We expected that the level of resources of a stratum that a species typically exploits would determine the dominance of either the exploitative or conservative strategy, as well as the similarity in functional traits between species. If this is correct, then canopy and subcanopy species will show an acquisitive strategy emphasizing traits targeting a larger size, whereas understory species will show a conservative strategy with traits promoting efficient biomass allocation. Two principal components (57.22% of the variation) separated palm species into: a) canopy and subcanopy species whose traits were congruent with the acquisitive strategy and that emphasized large size (i.e., height, carbon content, and leaf area), and b) understory species whose traits were associated with efficient biomass allocation (i.e., dmf and tissue density). Since palms are one of the most abundant life forms in tropical forests, exploring the variation in functional traits within this group could significantly improve our understanding of plant adaptation to environmental gradients.