Without a healthy base of vegetation, there is greater runoff of water. This upsets the balance of water circulation, which over time is likely to make a rain forest highly unstable.
Alcock disagrees with people who argue that the essence of the rain forest and its unique ecology can be maintained by preserving small sections of the rain forest. Damage to the overall system would probably limit the rain necessary to do that, he argues.
Less rain also means greater vulnerability to forest fires, further threatening the balance of the rain forest.
No Easy Solutions
Many other researchers have studied the links between tropical deforestation and climate change. Alcock said his study differs from most of that work because he focused on how altered weather patterns affect rain forest ecosystems at the local level, rather than studying the interrelationship of tropical deforestation and regional or global climate.
In the Amazon River Basin, Alcock noted, the loss of large areas of forest is likely to bring about the extinction of many species of animals that are dependent on a healthy forest environment.
"There are already a large number of species that are endangered because the forest itself is endangered," he said. "We might be able to keep a few animals at the zoos, but we'd surely lose a lot of amphibians, reptiles, and insects. We couldn't take them all."
Halting deforestation is a tough issue for society to address because millions of people living in and near the major remaining rain forests of Brazil, the Congo, and Southeast Asia are heavily dependent on the forest for their livelihood, Alcock noted. "You cannot say 'Leave the rain forests alone' when people are living in poverty," he said.
Although Alcock conducted his model-based study at Penn State, he said he hopes to extend the research through field work in the Amazon Basin.
He undertook the present study as a way to better explain the concept of feedbackexemplified by precipitation and evapotranspiration in the rain forestto his students in an introductory course on earth systems.
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