for National Geographic News
Nearly half of the world's 17,000 protected nature reserves are being
heavily farmed as rapid growth population growth drives poor people
to seek land wherever they can find it, two international
organizations report in a major new study. The impact on biodiversity
is dire, they say, arguing for a radical rethinking of conservation
policies in place today.
According to the report, the world's
biological diversity is more threatened now than at any time since
the extinction of the dinosaurs 65 million years ago.
Clearing
and using land for agriculture is one of the chief causes of the loss
of plant and animal species, says the report, which was done jointly
by the World Conservation Union (IUCN) and Future Harvest, an
agricultural research group.
The report calls for abandoning the traditional "fence-it-off" approach to protecting wildlife and adopting instead "eco-agriculture"—strategies based on the premise that natural ecosystems can be managed to simultaneously protect threatened species and help to feed the world's poor.
"The eco-agriculture approach recognizes the fact that endangered species and desperately poor humans occupy the same ground," said Sara J. Scherr, an adjunct professor of agriculture and resource economics at the University of Maryland. She and Jeffrey A. McNeely, chief scientist of IUCN, are co-authors of the report.
Barbara Rose, the executive director of Future Harvest, said the eco-agriculture approach is a dramatic break with both traditional conservation policies and common agriculture techniques. "It is a way to save wild biodiversity while also addressing the realities of human hunger and population growth," she said.
"Hot Spots" and Hunger
Nearly half of all tropical forests have been cleared over the last 400 years, converted to fields for annual crops, tree plantations and grazing lands. If forest clearing continues at present rates, the world's forests could lose more than half of their remaining species in the next 50 years, the researchers warn.
Conservation International has identified 25 biodiversity "hot spots" around the world—areas that have a high range of species and are heavily endangered by a host of causes. More than 1.1 billion people live within these "hot spots," notes the report. In at least 16 of the areas, the levels of malnutrition and hunger are high.
Population pressures, which are driving the encroachment into nature reserves and endangered habitats, are unlikely to ease. The researchers found that in 19 of the 25 biodiversity "hot spots," the populations are growing faster than in the rest of the world. In tropical wilderness areas, the rate of population growth is twice as high as the worldwide average.
The authors of the report say the most common approach to wildlife conservation—designating areas in which to protect threatened plant and animal species in their native ecosystems—is failing for several reasons.
For one thing, such areas are unable to withstand the intrusion of hungry people seeking land on which to grow crops to feed their families. At the same time, protected areas are often too small to maintain healthy populations of threatened species, or may exist as fragmented islands of habitat surrounded by cleared land, which impedes natural migration by wildlife.
Ecologically healthy levels of biodiversity are essential to agricultural productivity. Insects and other animals help plants reproduce, contribute to soil fertility and regulate pest populations. Trees and plants filter pollutants out of water and control floods. Tiny microorganisms in the soil break down organic matter, help move air, water and nutrients within soil, and destroy pests.
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