Biodiversidade e Funcionamento de Ecossistemas: síntese de um paradigma e sua expansão em ambientes marinhos

Abstract

BIODIVERSITY AND ECOSYSTEM FUNCTIONING: SYNTHESIS OF A PARADIGM AND ITS EXPANSION IN MARINE ENVIRONMENTS. The relationship between biodiversity and ecosystem functioning (hereafter BEF) became a prominent topic in Ecology. It represents the arising of a new paradigm started with the perception of the functional role of biodiversity to the functioning of ecosystems. Studies performed until now have shown significant effects of biodiversity on ecological processes and properties related to three main mechanisms: complementarity effects, selection effects and sampling effects. However, the magnitude and direction of biodiversity effects may vary according to the ecosystems and processes analysed making their generalization difficult. Our aim is to do a review on the subject focused on: a) a brief historic of the evolution and consolidation of the studies BEF; b) assess discrepancies between studies performed in terrestrial and aquatic environments, emphasizing recent contributions from marine environments; c) the actual knowledge and consensus about the BEF relationship and new perspectives of study. Despite the inicial criticisms, BEF studies are now consolidated in ecological literature. New methodologies and hypothesis have been developed and improved, increasing the range of ecosystems and processes investigated. Although there is a strong publication bias in the number of studies investigating certain ecosystems and processes, it is observed an increase number of studies performed in aquatic, mainly marine, ecosystems. Most studies have pointed out to positive effects of diversity as a Non-Transgressive Overyielding which may indicate the importance of the presence of species functionally superior in the community (sampling effects and selection effects). However, it is called in question the possible occurrence of complementarity effects, considering the scarcity of studies in larger temporal and spatial scales and investigating distinct ecological processes simultaneously. The manipulation of realistic diversity levels and the investigation of higher trophic levels may also add more realism to the analysis of biodiversity effects. BEF studies have provided valuable information on the possible effects of the actual losses of diversity on the rates of occurrence of ecological processes that regulate the ecosystem functioning. Keywords: Complementarity effects; selection effects; stability; trophic structure, multifunctionality and temporal complementarity.