Efeitos do mecanismo de Home Field Advantage na decomposição de detritos foliares de Myrcia ramuliflora em uma mata de restinga

Abstract

Decomposition is the main process by which nutrients and carbon are recycled from organic matter and reincorporated into the food chain and / or released into the atmosphere. Several hypotheses have been proposed to explain how interactions between plant debris and decomposing fauna influence decomposition dynamics in terrestrial ecosystems. The Home Field Advantage (HFA) hypothesis, predicts that the decomposition of detritus from a given plant will occur faster where the species commonly occurs compared to where it is absent, due to greater decomposing fauna specialization. However, little is known about whether the mechanisms responsible for HFA are triggered only by the presence / absence of co-specific debris, or whether they also vary due to a gradient of co-specific debris input. We verified along 41 plots distributed in a Restinga Forest, if the decomposition of leaf debris of Myrcia ramuliflora species in 164 litterbags (4 per plot) corroborated the HFA hypothesis. The plots varied in environmental conditions, presence and annual input of M. ramuliflora debris. Decomposition was estimated as the percentage of remaining mass. To test the occurrence and relative importance of the HFA hypothesis on decomposition in relation to other environmental variables, linear models with multiple predictors were ranked according to the Akaike selection criteria, using the SAM - Spatial Analysis in Macroecology version 4.0 package. Contrary to our expectations, the decomposition of M. ramuliflora did not vary systematically as a function of its presence or detritus input along the plots, and its decomposition was mainly influenced by soil nitrogen concentration. The low quality of the debris associated with the more general character of decomposing fauna of tropical environments can weaken or nullify the occurrence of the effects of HFA on decomposition in these environments. Future studies, however, need to test such effects on a larger number of species in order to have a more complete picture of the action scenario of the HFA mechanism in tropical ecosystems.