Species protection: Thousands of threatened tree species in South America

The Atlantic Rainforest, called Mata Atlântica in Brazil, is one of the most species-rich hotspots on our planet with around 15,000 described plant species. This subtropical forest ecosystem once stretched over more than 1.7 million square kilometers from northeast Argentina, Uruguay and Paraguay to northeast Brazil. Around 80 percent of this unique rainforest has already been destroyed, most of it over the past 50 to 70 years. The Atlantic rainforest is therefore much more threatened than the Amazon rainforest. And its deforestation and degradation have not stopped to this day.

Endemic species particularly affected

One conducted by scientists from Brazil, the Netherlands and France Research work is now the first to assess the level of threat to tree species in the Atlantic Rainforest according to the criteria of the International Union for Conservation of Nature’s Red List. It shows that 65 percent of all 4,950 tree species counted in the remaining Atlantic rainforest areas are threatened.

Things look even worse for the more than 2,000 species that are endemic to the Mata Atlântica, i.e. only found there. Of these, 82 percent fall into the “threatened” category. The researchers were no longer able to find 13 of the known endemic tree species in the areas examined and therefore classified them as possibly extinct. The good news is that they rediscovered five species that were already considered extinct in the wild according to the Red List. However, it is unclear to what extent these trees actually still exist in significant populations.

“The high number of threatened endemic species was a shock for us because we pursued a conservative approach,” says study coordinator Renato Lima from the University of São Paulo in Piracicaba. The research team took both intact and degraded forest areas into account in their investigation. But not all tree species are able to survive in degraded fragments. “It is therefore possible that the reality is even more worrying,” says Lima. The estimated biodiversity loss would have been even greater if only intact forest areas had been taken into account. Added to this is climate change, which could accelerate the extinction of species in the ecosystem in eastern South America, which depends on high rainfall.

Based on data from the Atlantic Rainforest, the study also extrapolates species extinction on a global scale. “Our forecasts suggest that 35 to 50 percent of the tree species on the planet could be threatened by deforestation alone,” says study co-author Hans ter Steege from the Naturalis Biodiversity Center in the Netherlands.

“The Atlantic coastal rainforest in Brazil is one of the most species-rich and biologically unique regions on earth, but it has been fragmented into many small relics due to land use,” says nature conservation expert Pierre Ibisch from the Eberswalde University for Sustainable Development, commenting on the study. »A few more protected areas here and there will not be enough to stop this landslide loss of life and functioning ecosystems in this region. To do this, a lot of area would simply have to be given back to the forest.

Deforestation continues

But Argentina, Paraguay and especially Brazil, which has the largest share of the Atlantic Rainforest, are still a long way from this approach. Of its original 1.3 million square kilometers, only around 12 percent remains. The ecosystem has been protected in Brazil since 1993, and “the deforestation, exploitation and suppression of primary vegetation or the regrowing forest” are prohibited by law. Nevertheless, the destruction of the Mata Atlântica has continued since then, with and without legal blessing in Brazil, for example for road construction, mining, dam construction, the expansion of cities and settlements, and the cultivation of sugar cane, soybeans and eucalyptus.

From 1995 to 2000 alone, the unique rainforest in the south and east of Brazil lost around 440,000 hectares. The annual deforestation rate has fallen to 11,339 hectares in the 2017/18 period. But since then it has been rising again. In 2021 and 2022, just over 20,000 hectares were destroyed, according to data compiled jointly by the SOS Mata Atlântica Foundation and the Brazilian Space Research Institute.