How much deforestation would be required to cause the cycle to degrade to the point of being unable to support rainforest ecosystems? How are the indigenous populations resisting deforestation?
These are very important questions because experts have been pointing , for some time, that Amazon deforestation is about to reach a certain threshold from which regions of the rainforest can undergo irreversible changes, in which their landscapes can become similar to those of cerrado (tropical savanna), more degraded, with scarce and sparse vegetation and low biodiversity. As climatologist Carlos Nobre puts it:
"Although we do not know the exact inflection point, we estimate that the Amazon is very close to reaching this irreversible limit. The Amazon has already 20% of its area deforested, equivalent to 1 million square kilometres, although 15% of this area [150,000 km2] is recovering".
A great number of studies and advances have been made in recent decades, to better understand the impacts of drought and extreme events on tropical forests and to the populations that inhabit them. Extreme events and deforestation can act synergistically in a two-way mode: deforested areas can affect regional climate, and the regional climate, in its turn, can amplify the impact of deforestation, by increasing tree mortality far beyond the limits of the deforestation edges . But not only extreme events are indicators of transformations. In the Amazon, on the other hand, forces acting through slow violences are affecting the bodies of indigenous people and animals and plants.
Imazon estimates indicate that deforestation in the Legal Amazon, an area comprising nine Brazilian states, reached 287 km2 in March 2018. For comparison purposes, in the same month, in 2015, deforestation was 58 km2, that is, it was five times smaller. There are recurrent denunciations of timber extraction and illegal occupation, stimulated by politicians and farmers. Other factors besides deforestation began to impact the Amazonian hydrological cycle, such as climate change and the indiscriminate use of fire by agriculturalists during dry periods. This hunger for development gave the country the second place among the largest exporters of agricultural products, but also a record of forest deforestation and violence against indigenous and political leaders of the forest – we remember the cases of the Corumbiara massacre and the murder of Chico Mendes and Dorothy Stang.
The elimination of felled trees and the clearing of areas to transform them into crops or pastures happens in tune with the increase in Brazilian meat exports and the strengthening of large chains of slaughterhouses, transforming areas of forest to give way to production, mainly, livestock and also soy. The advance of soybeans, in areas of deforestation in the Amazon, is the highest in five years. Planting of the grain in devastated areas grew 27.5% over the previous harvest, according to a report from the Soy Moratorium. In May, thousand hectares of forest were cleared due to the advance of agriculture, mining and theft of timber. Of these, many were deforested within Indigenous Lands and Conservation Units.
According to the Forest Transparency Bulletin of the Imazon Institute's Legal Amazon, deforestation in private areas was 59% in June 2014. The remainder was recorded in conservation units (27%) and agrarian reform settlements (13%). Indigenous lands had the lowest rate of only 1% of the total deforestation in the Amazon region, according to the report.
This is because protected areas and indigenous lands act as a buffer against deforestation. For example in three years, the Ka’apor have seized and torched trucks carrying stolen timber, and closed down 14 illegal roads running through their lands, the tribe says. The Munduruku have delineated their own land in an effort to face down the lawless miners and land grabbers, Ashaninka Indians, in the Upper Juruá region, in Acre, develop agroforestry production projects, which guarantee the food security of the communities as well as actions to protect their territory against the invasion of predatory activities. The land is located on the border with Peru, target of logging, mining and oil, as well as the action of drug trafficking cartels.
Sônia Guajajara, from the coordination of Articulation of the Indigenous Peoples of Brazil (Apib), argues that the elevated deforestation reveals the commitment of the Brazilian State to the environmental issue and to the policy of protection of the TIs. For Guajajara,
"Although the whole world is discussing the reduction of deforestation to contain global warming and Brazil has presented goals to reduce illegal deforestation, we are not even able to do so. This is very worrying. This has to do with the loosening of environmental legislation, with the advancement of agribusiness, of deforestation associated with the construction of hydroelectric dams and government development policies. Illegal logging has increased in Indigenous Lands. That's not new. We must have an effective policy of protection. It is not only now we're saying this".
In order to prevent the Amazon from reaching an irreversible limit, researchers suggest the need not only to control the deforestation of the region, but also to build a safety margin by reducing the deforested area to less than 20%. For this, in Nobre’s assessment, deforestation in the Amazon will have to be zeroed and Brazil have to fulfil the commitment made in the 2015 Paris Climate Agreement to reforest 12 million hectares of deforested areas in the country, of which 50,000 km2 are in the Amazon. In addition to zeroing deforestation, other important measures would be land regularization and support for management of indigenous lands.
Something which in my opinion sounds like asking the wolf to take care of the sheep. The Brazilian State on one hand makes minimal efforts to conserve the forests and to guarantee the rights and territories of the traditional and indigenous peoples, on the other, it supports with all their body and soul the dilapidation of the Amazonian ecosystems. We prefer to bet our chips on the action and initiative from the "bottom" , from the communities and broad networks formed by the forest peoples than in the powers "from above".
 Carlos Nobre and Thomas Lovejoy in http://advances.sciencemag.org...
 G. Sampaio, C. A. Nobre, M. H. Costa, P. Satyamurty, B. S. Soares-Filho, M. Cardoso, Regional climate change over eastern Amazonia caused by pasture and soybean cropland expansion. Geophys. Res. Lett.34, L17709 (2007).