Monday, January 20, 2014

Brazil’s Biodiversity

article from January 13, 2011
by Julie R Butler

Brazil is considered by biologists to be the most biologically diverse nation in the world. It is home to the largest number of different species, and it is the enormous Amazon Rainforest that holds the largest collection of living plant and animal species of them all regions. The entire rainforest covers a mind-boggling 5.5 million sq km (1.4 billion acres), and according to the World Wide Fund for Nature, it is home to one-tenth of all known species in the world. Sixty percent of the Amazon Rainforest lies within the boundaries of Brazil.

But the Amazon Rainforest is just one of Brazil’s many ecosystems, existing in the North Region of this immense country. The four other regions that exist in Brazil contain a wide variety of geographies and habitats. The Atlantic Forest is also vast and includes a diversity of ecosystems that range from tropical and subtropical jungles, to forest types known as semi-deciduous, tropical dry, montane moist, and mangrove, to coastal restigas, as well as the transitional areas between them all.

The Cerrado, which means closed, is a region that covers a huge swath of the central interior of Brazil with tropical savannah crossed by gallery forests that line the rivers and streams. It contains a surprisingly high level of diversity in the wide variety of grasses and twisted, woody trees that form nearly impossible to penetrate closed canopy forests.

In northeastern Brazil, there is an ecoregion called the Caatinga that is characterized as xeric shrubland and thorn forest. Here, the brief rainy season nurtures cacti, thorny brush, thick-stemmed plants, grasses that thrive in the arid climate, and a spurt of short-lived annuals. Water rights and irrigation policies are a major issue in the Caatinga.

At the other end of the spectrum is the Pantanal, a tropical wetland that is the world’s largest wetland of any kind. This is a floodplain ecosystem much like the Nile River in Egypt, with 80% of this river delta region becoming submerged during the rainy season. The water arrives as runoff from the Mato Grosso Plateau to the northeast, then slowly releases into the Paraguay River, which flows into the mighty Paraná, which empties into to the world’s broadest estuary, the Río de la Plata. The Pantanal ecosystem is a coming together of the surrounding bioregions, where the biology is adapted to the radical cycle of inundation and dehydration.

Altogether, the results are an enormous variety of species that exist in Brazil:

55,000 plant species
3000 freshwater fish
1622 birds
+520 mammals
468 reptiles

The significance of all this? Biodiversity is considered to be a measure of the health of the ecosystem. As the result of some 3.5 billion years of evolution, diversity of species can be seen as a survival tool of the ecosystem as a whole. The adverse effects inflicted on the planet by a single species should therefore be understood not only as a tragedy, but also a danger of huge proportions.

Julie R Butler is a writer, journalist, editor, and author of several books, including Nine Months in Uruguay and No Stranger To Strange Lands (click here for more info). She is a contributor to Speakout at Truthout.org, and her current blog is Connectively Speaking.
email: julierbutler [at] yahoo [dot] com, Twitter: @JulieRButler