Amazon Forests Crucial for Species Survival

Amazon Forests Crucial for Species Survival





    
January 2007  - Conservation of 
extensive Amazon forest reserves is even more important than 
previously thought, according to a new study by an 
international scientific team. The research, to be published 
in tomorrow's issue of the journal "Science," spotlights the 
importance of protecting the Amazon from fragmentation. 
The article summarizes bird survey results from the world's 
largest and longest running experimental study of forest 
fragmentation - the Biological Dynamics of Forest Fragments 
Project at the National Institute for Amazonian Research. 
Between May 2000 and August 2006, Brazil lost nearly 150,000 
square kilometers (57,915 square miles) of forest - an area 
larger than Greece. Across the entire Amazon since 1970, an 
area four times that size has been destroyed. 
Poor farmers use fire for clearing land in the Brazilian 
Amazon. (Photo M.O. Andreae courtesy Max-Planck Institute) 
Every year, land clearing for agriculture, ranching and 
logging - both legal and illegal - shrinks the Amazon forest 
by thousands of square kilometers, leaving small forest 
fragments isolated from one another by cleared land. 
Many species that occur in intact forests prior to destruction 
will not be present in a small fragment. But the scientists 
wanted to learn if these same species would be found in an 
equally small plot surrounded by untouched forest. 
They say the answer to this question has profound management 
implications because it weights the relative importance of 
area and isolation in the design of forest reserves. 
The study is sponsored by the Smithsonian Tropical Research 
Institute in Panama, the Smithsonian Institution in 
Washington, DC, and the National Institute for Amazon Research 
in Brazil. 
The scientific team, headed by Gonçalo Ferraz from the 
National Institute for Amazon Research, studied a 13 year data 
set of more than 40,000 bird captures in 23 isolated and 
non-isolated plots of forest, ranging from one to 600 
hectares. 
Richard Bierregaard, Jr. and Philip Stouffer with the 
Biological Dynamics of Forest Fragments Project led the data 
collection as part of the experimental study founded by Thomas 
Lovejoy and his Brazilian colleagues. 
Forest view from tower in Manaus, Brazil (Photo by M.O. 
Andreae courtesy Max-Planck Institute) 
The scientists found that conservation of large areas is 
important because the forest is diverse. 
"What might look like a vast mantle of homogeneous green is 
actually a multicolored mosaic," said Lovejoy, who is 
president of the The H. John Heinz III Center for Science, 
Economics and the Environment in Washington, DC, and the 
founder of the public television series "Nature." 
"Species that occur throughout the forest at the large scale 
actually may have very specific requirements at the fine 
scale," he said. 
This detailed look at the dynamics of 55 bird species allowed 
an unprecedented test of theories about the effects of reserve 
size and isolation on the local extinction and colonization of 
species. 
The study shows that some species vanish because they do not 
survive in a given site, others because they do not colonize 
new sites that become available. The two processes may also 
act in combination. 
The effects of area size on the occurrence of bird species are 
much stronger than the effects of isolation, the scientists 
concluded. 
"It is no surprise that small isolated fragments lack many 
species," said Ferraz. "Many birds are so uncommon that they 
will rarely occur in small plots even in the middle of vast 
undisturbed forest." 
But large areas of forest encompass a wide enough variety of 
local conditions and species, to ensure the survival of the 
Amazon and its inhabitants, said Ferraz and his team. 
Hyacinth macaws inhabit the Brazilian Amazon. Recent estimates 
of the number surviving in the wild have ranged from 2,500 to 
5,000. (Photo courtesy Amazon Image) 
The Amazon rainforest holds one fifth of the planet’s plant 
and animal species, more than 200 indigenous cultures, and 30 
million people in search of sustenance and wealth. 
In the past four years, under the administration of President 
Luiz Inácio Lula da Silva, Brazil has set aside more than 20 
million hectares of the Amazon basin from development, giving 
the country the largest protected areas system in the world. 
Brazil now has some 110 million hectares, an area twice the 
size of France, under some form of protection. 
In December, the government of the Brazilian state of Pará 
established the largest protected area ever, 15 million 
hectares in northern Brazil. 
Stretching from the border of Guyana and Suriname in the north 
to south of the Amazon River, the seven new protected areas 
created by Pará Governor Simão Jatene include the world’s 
largest tropical forest reserve. 
The scientists say their findings confirm the importance of 
this action and other similar efforts to conserve extensive 
forested regions.