Over time, man has greatly accelerated the rate of extinction of species, to the point of having become, at the moment, the main agent of extinction. In part, this situation is due to the misuse of natural resources, which has triggered a new cycle of extinction unprecedented in the geological history of the earth.
Currently, the main causes of extinction are the degradation and fragmentation of natural environments, resulting from the opening of large areas for grazing or conventional agriculture, disorderly extractives, urban expansion, expansion of road networks, pollution, forest fires, and lake formation for hydroelectric and surface mining. These factors reduce the total habitats available to the species and increase the degree of isolation between their populations, reducing the gene flow between them, which can lead to losses of genetic variability and, eventually, the extinction of species.
Another important cause that leads species to extinction in Brazil is the introduction of exotic species. These species, because of their competitive advantages and favored by the absence of natural predators and environmental degradation, dominate the niches occupied by native species. With increasing international trade, individuals are often translocated to areas where they are more efficient than native species in resource use. In this way, they multiply quickly, causing the impoverishment of the environments they inhabit, the simplification of ecosystems, and the extinction of native species.
Brazil has six different types of forests: the Atlantic Forest, the Caatinga, the Cerrado, the Araucaria Forest, the Pantanal and the Amazon Forest. Among them, only the Amazon Forest has a relative degree of preservation, despite the increase in deforestation in recent years.
The Brazilian forest that suffered most from the devastation was the Atlantic Forest. As it lies on the coast of the country, it became the first place to be occupied by society. It is estimated that only 7% of the original Atlantic Forest vegetation remains. Another forest, the Cerrado, also suffers from deforestation, with 20% of the original vegetation remaining. Its destruction began in the eighteenth century, when the colonizers began their occupation of this territory. However, it was in the middle of the twentieth century that the devastation in this forest occurred most intensely, with the expansion of agricultural activities and livestock.
The Amazon Forest, currently the most preserved area, is increasingly suffering from deforestation growth. The main reason is the expansion of the country’s agricultural frontier.
It began to suffer from deforestation in the 1970s, when the Trans-Amazon Highway was built. After that, much of its area began to be destroyed for agricultural practices and cattle breeding.
The conservation of Brazilian biodiversity for present and future generations and the management of the conflict between conservation and unsustainable development are currently the greatest challenges of the Ministry of the Environment. MMA therefore has enormous responsibilities for species threatened with extinction. First of all, the lists of endangered species should be expanded, with the purpose of quantifying the problem and allowing the direction of actions to solve it; second, the protection and recovery of these species should be focused on; third, and perhaps most complex, a development model that ensures the sustainable use of the components of biodiversity must be implemented.
Brazil is a signatory to important international agreements and conventions, both in terms of species conservation and endangered habitats. In addition to the implementation of these instruments by countries, national laws and regulations were also created, aiming at the conservation of Brazilian biodiversity and protection of natural ecosystems.