Deforestation from increased grazing and agriculture has destroyed 17 percent of the native vegetation in Brazil's Pantanal, considered the world's largest wetland.
A new study published by Conservation International sounds an alarm for the Paraguay River Basin, which includes the Pantanal. Continued deforestation at the current rate would cause all of the Pantanal's original vegetation to disappear in 45 years, according to CI researchers in Brazil.
Overall, opening the region to more grazing and agriculture, including the transformation of native pasture to farmland, has destroyed almost 45 percent of the original vegetation in the Paraguay River Basin. The river basin covers approximately 600,000 square kilometers, 60 percent of it within Brazilian territory. It includes the Pantanal, which comprises 41 percent of the entire basin. The Pantanal is a Brazilian National Heritage site, a significant site of international relevance according to the RAMSAR Wetlands Areas Convention, and a UNESCO Biosphere Reserve.
The CI scientists analyzed satellite images to compare the proportion of deforested areas with those that still have native vegetation. They concluded that agriculture, cattle grazing and coal mining are the major threats to the Paraguay River Basin, a significant hydrographical drainage of the South American continent.
Titled "Estimated Loss of Natural Area in the High Paraguay River Basin and the Brazilian Pantanal," the report produced by the Pantanal Program of CI-Brazil depicts a critical situation. As of 2004, it says, approximately 44 percent of the area's original vegetation had been altered, with some districts in the Paraguay River Basin losing more than 90 percent of their vegetation.
"It is extremely important to conserve the areas surrounding the Pantanal lowlands, because they are the headwaters of the rivers that make up the Pantanal," said Sandro Menezes, manager of CI-Brazil's Pantanal's Program. "These locations contribute to wildlife populations and serve as refuges for the fauna during unfavorable seasons, sheltering species that migrate to avoid floods and climate extremes."
Losing native vegetation causes soil degradation and changes the hydrological processes, which determine the dry and wet cycles and are largely responsible for the biological richness of the region. That in turn can compromise resources such as food and breeding sites offered by the forests and other types of vegetation. An example is the hyacinth macaw, a species threatened with extinction, which depends on a tree commonly called 'manduvi' (Sterculia apetala) for shelter and reproduction. Without this specific tree, chances are that the hyacinth macaw will disappear.
According to the report, urgent actions required to reverse the situation include increased government regulation and better coordination of conservation efforts at various government levels (municipal, state and federal); a review of current legislation regarding protected areas and legal reserves for the region; and implementation of a broad environmental restoration program in devastated areas.
Source : Conservation International