Intraspecific variation of leaf traits in tree plantings of different ages in a tropical forest

Abstract

Response functional traits are characteristics related to how organisms respond to variations in abiotic or biotic factors, which can vary along an environmental gradient. Variations in traits within a community arise due to the arrival or departure of species, but also due to variation across individuals of the same species. The objectives of this study were: (i) to assess differences in the intraspecific variation (ITV) of leaf traits in restoration sites of different ages in a tropical forest; (ii) to observe if species of the same ecological group exhibit similar variation in resource use traits over time; and (iii) to assess the relationships between pairs of traits for each species at different sites. The tree species Alchornea triplinervia, Calophyllum brasiliense, Guarea guidonia, Inga laurina, and Pseudobombax grandiflorum were evaluated in 5-, 13-, and 25-year-old plantings in an area of Atlantic Forest. The results showed that, for most traits, the highest ITV was observed in the oldest planting and the species did not show equivalence in the pattern of trait changes, regardless of their ecological group. Most correlations between pairs of traits differed among plantations of different ages. We showed that intraspecific variation does not necessarily occur in a similar way among species of the same ecological group and suggest that ITV in a given area is related to environmental rather than ontogenetic factors. We also demonstrated that even well-established correlations between pairs of traits do not always persist over time.