O papel da diversidade funcional sobre a produtividade e interações em espécies de plantas arbóreas da caatinga

Abstract

In the study of community ecology, biological interactions are key ecological processes that influence the assembly of the community. Thus, the type and intensity of interactions between plants in a community where plants can compete or complement each other in relation to the acquisition and investment of resources is linked to the productivity of the system which in turn can be influenced by the functional diversity of species. The present study verified the influence of functional diversity on species interactions and productivity in controlled systems. It was simulated clumps of vegetation in early environments of the Caatinga where we had as target species Anadenanthera colubrina and Mimosa caesalpinifolia and as neighboring species Libidibia ferrea and Amburana cearensis. Dry biomass was analyzed, calculating the interaction index between plants (LNRR) and relative yield (RY). We hypothesized that high functional diversity and positive interactions would increase productivity. We found that high functional diversity is not necessarily related to high productivity, because the functional identity of the species involved is a key factor for interactions and, as a consequence, for productivity. We have seen that even if the focal species are of the same functional group their neighboring species (Libidibia ferrea and Amburana cearensis) had a higher biomass production when it was associated with the focal species Mimosa caesalpinifolia. This tells us that probably the identity of this species as focal has provided greater productivity in our systems. Amburana cearensis was the neighboring species that managed to obtain an overproduction in mixtures than alone and which experienced facilitation interactions (when associated with the focal species Mimosa caesalpinifolia). In view of this, we propose that future studies be carried out, especially in the field, on mixtures with Mimosa caesalpinifolia and Amburana cearensis, as this system could be a good potential for recovery of degraded areas and conservation of biodiversity.