Natural and anthropic forest fragments have distinct ecological behavior due to their different origin and landscape context

Abstract

We tested the hypothesis that plant populations in natural fragments have distinct ecological behavior in relation to anthropic fragments. We selected the species Myrcia splendens (SW.) DC. in 2 forest fragments located in southeastern Brazil that present different origins and landscape contexts. The natural fragment originates from landscape relief variations and is inserted in a native grassland matrix, while the anthropic fragment originates from fragmentation due to area conversion and is inserted in an agricultural matrix. We established transects covering an area from one border to the other in each fragment, and we established subunits of 400 m² within them. Within each subunit we measured all individuals of M. splendens at all establishment stages (seedlings to established trees). We monitored population behavior in the two fragments for 4 years, evaluating their spatial structure, temporal behavior, and age structure. The two populations present distinct ecological behaviors associated with their different origins and landscape contexts; the natural fragment is exposed to disturbances it has adapted to throughout the evolutionary process, whereas the anthropic fragment is subject to new evolutionary disturbances, such as effect edge, cattle, and recurrent fire