Atlantic Forest spontaneous regeneration at landscape scale

The Atlantic Forest suffered five centuries of continuous deforestation related to successive economic cycles, and is now reduced to 11.7 % of its original cover. The Atlantic Forest Restoration Pact was launched in 2009 and aims to restore 15 million hectares until 2050. Natural regeneration can play an important role in meeting this target, however little attention has been paid to this process and there is a gap in the knowledge about its driving factors at the landscape scale. We mapped forest cover of an Atlantic Forest municipality in Southeastern Brazil, in five timeslots between years 1978 and 2014, and used the weights of evidence method for modeling its spatial dynamics, in order to understand where natural regeneration is occurring and which are the main factors related to this phenomenon. In 36 years, forest cover increased 3,020 hectares (15.3 %), related to the decreasing of both rural population (R² = 0.9794, p = 0.0013) and cropland cover (R² = 0.8679, p = 0.0212). Landscape metrics shows the increment of number of fragments and structural connectivity among them. The main spatial variables influencing forest cover dynamics were topographic position, slope, solar radiation, soil type and distance to forest, urban areas and roads. Secondary forests provide ecosystem services that can turn into economic benefits, and natural regeneration can reduce restoration costs to the municipality. The cost of active restoration of the same area would have meant a total expense of U$ 15.1 million (U$ 419 k/year). We show here that spontaneous regeneration must be accounted for and incorporated into the spatial planning of Atlantic Forest restoration.