Humans as agents of change in forest landscapes

Forest systems play a crucial role in biogeochemical cycling and provide a variety of ecosystem services at multiple scales. Considerable progress has been made in understanding the dynamics of tropical and temperate deforestation and land-use and cover change. However, less attention has been dedicated to understanding the social and biophysical conditions under which reforestation occurs. Recent research documents the experiences of many countries that have undergone transitions from a period of high deforestation to a period of declining deforestation or even net reforestation. However, these transitions take place across a range of temporal and spatial scales. Here, we review global forest-cover trends and social processes affecting forest cover and then focus on a comparison of reforestation in the states of São Paulo, Brazil, and Indiana, United States. Both states have undergone extensive deforestation but now show forest restoration alongside continuing deforestation. Our focus on forest change at the state level permits a detailed examination of deforestation and reforestation dynamics and of the diverse social factors that underlie these changes. Among these factors, human values and attitudes appear most important.