The area of the Brazilian Amazon affected by forest degradation--where forest biomass is lost but not completely converted to another use--is greater than the area affected by deforestation, according to a long-term study by Eraldo Aparecido Trondoli Matricardi and colleagues. Between 1992 and 2014, the total area of degraded forest was 337,427 square kilometers, compared to 308,311 square kilometers that was deforested. The findings have implications for global greenhouse gas emissions and species loss, among other factors. Degradation is more difficult to measure and monitor than deforestation, although several international environmental initiatives such as the United Nations Convention on Climate Change single out restoration of degraded forest as a key focus. Degradation activities such as burning, selective logging and forest fragmentation can be hard to spot under an existing forest canopy. Matricardi et al.'s analysis of satellite imagery of the Brazilian Amazon showed where degradation persisted and reoccurred over the 25-year period. During that time, national policies did contribute to a decline in deforestation, where forest is converted to an entirely new use such as pastureland, the researchers noted. But by 2006 to 2010, the average annual rate of forest degradation by logging and burning was almost equal to deforestation rates, and by 2014 degradation rates had exceeded deforestation rates.
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Journal
Science