Background/Question/Methods Edge influence is one of the most important and most studied mechanisms by which habitat loss and fragmentation affect biodiversity. Even so, we still little knowledge of edge influence in a variety of ecosystems, including the two Brazilian biodiversity hotspots: the Cerrado and the Atlantic Forest. I performed a review of studies of edge influence in these environments to assess how research in them developed through time and what general patterns may be observed. For this, I searched the Web of Knowledge database for the search terms "Edge", "Effect* OR Influence" and either "Atlantic Forest" or "Cerrado", excluded studies that did not directly assess edge influence in these environments and included other studies I had previous knowledge of. Based on these studies combined with my own research, I propose a model of how edge influence may occur in these environments and indicate gaps in research.
Results/Conclusions There were 43 papers directly related to edge influence in the Cerrado and 173 in the Atlantic Forest; the first papers were published in 1999 and 1998, respectively. Vegetation, plant-animal interactions and insects were much studied in both systems, but birds and mammals only in the Atlantic Forest. One of the most important edge effectsin the Cerrado seems to be the invasion by African grasses, but changes in vegetation structure, microclimate and other variables were also observed. It is therefore possible that edge influence in the Cerrado is driven at least in part by African grass invasion, more than by changes in microclimate.Notwithstanding the increase in number of studies over the years, some issues remain little explored.For example, estimates of distance of edge influence are important for management but not often found in these studies.Our understanding of how edges affect microclimate is also still limited, especially in the Cerrado. Studies of edge influence on vertebrates were also rare in the Cerrado, and studies on insects were concentrated on groups such as ants, beetles and butterflies in both systems. In addition, fire-created edges have been little studied despite the high frequency and extent of this disturbance.
