Influence of adjacent matrix and edge effects on natural regeneration of a terra firme forest in central Amazonia

Abstract

One of the main consequences of deforestation in the Amazon rainforest is the edge effect, which in turn alters the microclimatic conditions of the environment and impacts the remaining forests, affecting natural regeneration and the functional characteristics of plants. These changes influence the forest's ability to recover over time. This study evaluates how the edge effect impacts regeneration in a terra firme forest in Central Amazonia, considering different adjacent matrices, such as pastures and regenerating forests. Conducted at the Experimental Farm of the Federal University of Amazonas, the study used three 100 x 100 m plots, with two near the matrices and one inside the forest. Microclimatic variables, canopy openness, and leaf traits of regenerating individuals were collected to analyze their functional characteristics, focusing on the C.S.R. ecological strategy and chlorophyll fluorescence. The results showed that microclimatic variables and light-use efficiency vary along the edge-to-center gradient, with particular emphasis on the first meters of the edge. Furthermore, the edge effect favors competitive traits in regenerating individuals but also promotes stress tolerance. Even after 47 years, the edge effects persists, although they are partially mitigated by adjacent regenerating forests, especially when compared to pasture edges, highlighting differences in community structure and eco-physiological responses of the regenerating individuals.

Keywords: C.S.R. ecological strategy; Fluorescence; Functional traits