Relação entre características funcionais e desempenho de espécies arbóreas na restauração florestal: uma abordagem experimental

Abstract

The successful restoration of deforested forests initially depends on the selection of species capable of establishing themselves in the degraded site. To facilitate the choice of species, classification into successional groups is commonly used, most often in pioneer and non pioneer species. However, this classification has been confusing due to the large number of parameters that can be used, making it difficult to compare the results of different studies on forest restoration. In this context, the study of functional traits of tree species can help to choose the appropriate composition of species to be reintroduced, as understanding the correlations between different characteristics and their interactions with abiotic components makes it possible to make better predictions of species performance. In the first chapter of this study, we evaluated the survival and initial growth of plants from 30 species reintroduced into an area of deforested forest, over the course of the first year of plant development. We describe the variation of functional traits of plants at the seedling stage and relate it to pre-established successional groups, pioneers and non-pioneers. Furthermore, we describe the initial growth of the plants, which allows us to quantify the variation in the rate of instantaneous increase in biomass over time. Our results showed the fast-slow growth continuum based on resource allocation strategies rather than a clear distinction between pioneer and non-pioneer species. Functional traits associated with acquisitive traits, such as high values of specific leaf area and proportion of biomass allocated to roots, and low values of leaf dry mass content and seed mass, tended to be more common among pioneer species, but were not associated with species classified as non-pioneers. Furthermore, this study showed that functional traits influenced species survival and growth patterns. In the second chapter, we evaluated the phenotypic plasticity of eight tree species during four months as a function of variation in soil chemical parameters. Our results showed that species with acquisitive characteristics had greater biomass plasticity as a function of variation in soil chemical parameters. The biomass of these species increased in soil treatments with addition of organic matter. Conservative species did not respond to different soil treatments, showing that initially their growth is less dependent on soil conditions. In addition, we evaluated the intraspecific variation of leaf and root traits as a function of plant growth, and indirectly in response to soil conditions. The allocation of resources for the formation of the root system decreased with plant growth, which is related to the environment where the limiting resource was found, in this case, below ground. Overall, we show that attributes influence growth rates and species in the field. Furthermore, the variation in the size of individuals of acquisitive species initially responds to soil conditions. Therefore, functional traits can be used to predict plant performance in response to environmental conditions in degraded areas, thus aiding in more efficient planning of forest restoration projects.