A recent study conducted by researchers at the Australian Catholic University, Columbia University and the University of Massachusetts has found that collective property rights in Indigenous territories in the Brazilian Amazon lead to higher rates of reforestation. The study compared secondary forest growth on land inside Indigenous territories to growth on land outside, and found that the Indigenous-controlled forests experienced a 2.21% to 5% increase in growth with trees that were 2.2 to 2.8 years older.
The study, titled “Collective property rights lead to secondary forest growth in the Brazilian Amazon,” was published in Proceedings of the National Academy of Sciences. The researchers used MapBiomas annual land use images to calculate secondary forest cover, and employed a geographic regression discontinuity design to compare similar lands under dissimilar control. The data showed that the Indigenous territories with Indigenous legal control had the highest rates of secondary forest recovery.
The researchers suggest that collective property rights were a significant factor in the growth, as it allows local stakeholders to make decisions about how their land is used. The Brazilian Amazon is home to 726 Indigenous territories covering 13.8% of Brazil. There are more than 250 Indigenous groups speaking more than 150 distinct languages. Four hundred eighty-seven Indigenous territories have established rights to their territories, while most others are in the process of establishing their legal control.
Secondary forests have been getting increased attention due to the rampant loss of original forests and because they are a natural source of carbon sequestration. Nations around the globe have individually committed to protecting, planting, and reforesting land as part of climate change agreements. The commitments add up to an area of new forest larger than the United States.
Even if the planet was not facing carbon-induced climate change, deforestation negatively affects land quality by increasing soil erosion, decreasing soil nutrients, causing the loss of springs and natural waterways, damaging habitats, and endangering local species. Secondary forest regrowth can rebound land from many of these effects, mitigate biodiversity loss, and provide new habitats for threatened species.
The Amazon rainforest is also an intensely dense location of biological diversity that has been a significant source of pharmaceutical compounds used around the world. About 40% of pharmaceuticals are derived from plants, and most of those were discovered in the Amazon with more likely yet to be discovered.
The study highlights the importance of collective property rights in Indigenous territories in promoting higher rates of reforestation. This has important implications for efforts to combat climate change and mitigate biodiversity loss in the Brazilian Amazon.