Light and dispersal strategies structure palm community along an elevation gradient in the Atlantic Forest

Abstract

Light availability and seed dispersal can play a determinant role for plant growth and survival. The intricate interplay among these factors, coupled with pronounced topographic and elevational variation, may influence forest composition and structure. Despite the structural significance of palms within the Atlantic Forest, they are scarcely represented in both inventories and ecological studies. Additionally, functional trait variation among palm species is barely tested, and species are usually categorized into one or two functional types. We examined a palm community in terms of floristic composition and species replacement along an elevation gradient from 0 to 1400 m. Furthermore, we measured a set of morpho-physiological traits strongly associated with growth and survival strategies, such as photosynthetic capacity through Rapid Light Curves, leaf traits, height and fruit size and number. Our findings reveal highest richness from 300 to 800 m. Otherwise, palm density increased along elevation, peaking after 1200 m, mainly associated with E. edulis increase in density along elevation. Additionally, traits associated with enhanced light capture and dispersal capacity, i.e., higher photosynthetic capacity, height, and fruit number, were common among species widely distributed along the entire elevation gradient, such as Euterpe edulis M. and Geonoma schottiana M. In contrast, species with narrower distributions, exhibit the opposite traits. In conclusion, in our study area there is an integral role of light response and dispersal capacity in shaping the palm community structure in the Atlantic Forest along an elevation gradient from 0 to 1400 m.