AR-News: FORESTS: Climate Change Impacting World’s Last Large Intact Habitats

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FOREST CONSERVATION NEWS TODAY
Climate Change Impacting World's Last Large Intact Habitats 
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Forest Networking a Project of Forests.org, Inc.
 
 http://forests.org/ -- Forest Conservation Portal
  http://www.EnvironmentalSustainability.info/ -- Eco-Portal
   http://www.ClimateArk.org/ -- Climate Change Portal
    http://www.WaterConserve.info/ -- Water Conservation Portal
 
March 10, 2004
OVERVIEW & COMMENTARY by Glen Barry, Forests.org

Atmospheric changes are impacting forest ecology in fundamental 
ways.  Research to be published tomorrow in the journal Nature 
has found that Amazonian rainforests are changing markedly both 
in terms of species and ecosystem outputs.  The study finds that 
seemingly pristine habitats are changing dramatically as a 
result of rising atmospheric carbon dioxide from human caused 
emissions and deforestation.  

The Earth is entering an era where even the last relatively 
large blocks of undisturbed primary habitats are ecologically 
diminished by the sheer scale of human endeavors.  Loss of large 
and natural habitats (both species and ecosystems), upon which 
all life is dependent, will mean an end to civilized human 
societies and their economies.  

Global ecological sustainability depends upon urgent and massive 
concurrent international programs to decrease greenhouse gas 
emissions, and conserve and restore natural habitats.  Insights 
on making this happen are always appreciated at Earth Talk:
http://environmentalsustainability.info/talk/
g.b.
 
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RELAYED TEXT STARTS HERE:

Title:  UNDISTURBED AMAZONIAN FORESTS ARE CHANGING, SAY 
SCIENTISTS
Source:  Copyright 2004, Nature
Date:  March 10, 2004 
Byline:  Press Release

A research team of U.S. and Brazilian scientists has shown that 
rainforests in central Amazonia are experiencing striking 
changes in dynamics and species composition.  

Although the cause of these changes-in what are believed to be 
completely undisturbed, old-growth forests-is uncertain, a 
leading explanation is that they are being driven by rising 
levels of carbon dioxide in the atmosphere.  

Carbon dioxide levels have risen by 30% in the last 200 years as 
a result of industrial emissions, automobiles, and rapid forest 
burning, especially in the tropics.  Much of this increase has 
occurred since 1960.  Plants use carbon dioxide from the air for 
photosynthesis.  

"The changes in Amazonian forests really jump out at you," said 
William Laurance, a U.S. scientist with the Smithsonian Tropical 
Research Institute in Panama.  Laurance is the lead author of 
the paper, which appeared this week in the scientific journal 
Nature.  "It's a little scary to realize that seemingly pristine 
forests can change so quickly and dramatically."

For the past two decades, the research team studied the fate of 
nearly 14,000 trees in the central Amazon, scattered across a 
landscape of 120 square miles in area.  During the course of the 
study, most species of trees began growing faster.  The forests 
also became more dynamic, with existing trees dying faster and 
being replaced by young new trees.  

Even more important is that the species composition of the 
forest is changing.  "There clearly are winners and losers," 
said Alexandre Oliveira of the University of São Paulo, Brazil, 
another team member.  "In general, large, fast-growing trees are 
winning at the expense of smaller trees that live in the forest 
understory."

"The decline of many small trees is intriguing because they tend 
to be so specialized," said Henrique Nascimento, a Brazilian 
researcher at the Smithsonian Tropical Research Institute.  
"They live in the dark interior of the forest, and are the only 
trees that can flower and reproduce in deep shade."  

The most likely reason for these changes, say the researchers, 
is that rising carbon-dioxide levels are fertilizing the 
forests, leading to faster growth and more competition among 
trees for light, water, and soil nutrients.  Under these 
conditions, big, fast-growing species of trees probably have an 
advantage over small, slower-growing trees.

"Sadly, this could be a signal that the forest's ecology is 
changing in fundamental ways," said team-leader Laurance.  
"Tropical rainforests are renowned for having lots of highly 
specialized species.  If you change the tree communities then 
other species-especially the animals that feed on and pollinate 
the trees-will undoubtedly change as well."

"This appears to be yet another signal of effects on nature from 
increasing greenhouse gas concentrations and associated climate 
change," said Thomas Lovejoy of the Heinz Center for Science, 
Economics and Environment in Washington, D.C., who helped to 
establish the tree study in central Amazonian over two decades 
ago.  "We really need more research to see if these remarkable 
changes are also happening in other tropical forests around the 
world.  If they are, then it's likely that even the world's 
remotest forests are now being altered by human activities."


For further information, contact:

Dr William F. Laurance
Smithsonian Tropical Research Institute
Balboa, Panama
Phone: 507-314-9206 and 507-212-8252
Email: LauranceW at tivoli.si.edu

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information rests with the reader.  For additional forest 
conservation news & information please see the Forest 
Conservation Portal at URL= http://forests.org/

Networked by Forests.org, Inc., gbarry at forests.org

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"Never doubt that a small group of dedicated citizens can change the world. 
Indeed, it's the only thing that ever has."      Margaret Mead
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