The well-founded alarm over the rapid loss of the world’s old-growth forests has overshadowed the equally notable increase in the area once used for crops and pasture that has reverted to secondary forest. The Food and Agriculture Organization of the United Nations (FAO) estimates that Latin America alone has 165 million hectares of such forest, an area more than three quarters the size of Mexico.

To learn more about the social and silvicultural dynamics of these secondary forests, a team of researchers from the National Agricultural University La Molina in Peru, the Center for International Forestry Research, and the International Center for Tropical Agriculture (CIAT), surveyed 167 small forests and 16 medium-sized cattle ranchers in agricultural frontier communities near Pucallpa, Peru. The recent paper ’Can Secondary Forests Mitigate Primary Forest Depletion? Implications from Small-Scale Farms in the Peruvian Amazon’ analyzes the survey’s results.

The authors show that over time the percentage of land covered with primary forests in small farms dedicated primarily to slash and burn agriculture declines, but farmers devote more land to secondary forest. Cattle ranchers had comparatively little forest of any type. Small farms in communities settled twenty to forty years ago had an average of 23% of their land in secondary forest higher than five meters, while only 13% of the land was in secondary forest in small farms in newer communities. (The small farms in both the newer and older communities had an average of around 26 hectares.)

The main reasons farmers have secondary forest are to provide fallow and because they lack sufficient resources to grow more crops. Nevertheless, secondary forests also provide farmers fuel wood and timber for domestic use as well as offering environmental benefits such as biodiversity conservation and carbon sequestration.

Once farmers build up their secondary forests they rely less on primary forests to grow their crops, thus reducing the pressure on primary forests. Farmers prefer to clear secondary forest because it requires less labor to clear. Thus, 53% of farmers surveyed cleared only secondary forest to produce their crops, even though almost two-thirds of those farmers still have primary forest available.