World's Forests Increasingly Fragmented, Deteriorating - Mongabay
The world's forests are fragmented and deteriorating, states a new paper published in Science Advances. After analyzing satellite imagery and compiling data from long-term fragmentation studies, the authors conclude that 70 percent of remaining forest land exists within 1 km of an edge, which negatively impacts their fauna, flora, and ecosystem services.
"Nearly 20 percent of the world's remaining forest is the distance of a football field—or about 100 meters—away from a forest edge," says Nick Hadded, corresponding author of Habitat fragmentation and its lasting impact on Earth’s ecosystems. "Seventy percent of forest lands are within a half-mile of a forest edge. That means almost no forest can really be considered wilderness."
The authors report that development, agricultural expansion and urban growth are rapidly carving natural areas into increasingly smaller sections. In Brazil's Atlantic Forests, for example, less than 9% of the remaining intact areas are farther than 1km from an edge. These findings, coupled with a meta-analysis of seven long-term fragmentation experiments on five continents paints an alarming outlook for the future of our forests.
"The initial negative effects were unsurprising," Haddad said in a press release, "But I was blown away by the fact that these negative effects became even more negative with time. Some results showed a 50 percent or higher decline in plant and animals species over an average of just 20 years, for example. And the trajectory is still spiraling downward."
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http://news.mongabay.com/2015/0324-lbell-forest-fragmentation.html
