Thanks to Brad Plumer and the commitment of the New York Times to continue covering the complex topic of climate change in interesting, and sometimes hopeful ways:
In the 1980s, an ecologist named Thomas Lovejoy conducted an unusual experiment in Brazil’s Amazon rain forest. As loggers moved in with chain saws to clear trees for cattle pasture north of Manaus, he asked them to leave untouched several small “islands” of forest to see how the animals within them fared.
The results were unsettling.Even in the largest protected forest fragments, 250 acres in size, the number of bird species living beneath the canopy declined by half within 15 years. The smaller isolated populations were far more likely to succumb to disease or climate fluctuations or demographic bad luck than a larger population would have.
That experiment helped establish a grim rule of thumb among biologists: When a species becomes isolated in a small disconnected patch of habitat, unable to breed with larger populations elsewhere, it runs a much higher risk of going extinct locally. And since many of the world’s forests are increasingly fragmented, carved up by roads and farms, it seems inevitable that many species within those remaining patches will soon vanish forever.
But in recent years, some ecologists have asked whether they can help stave off an extinction crisis by, in effect, running Dr. Lovejoy’s experiment in reverse. The idea is to link together the world’s remaining forest islands by planting small corridors of trees between them, allowing native birds, mammals and plants to spread between the fragments, mingle with their brethren and become more resilient against extinction threats.
In a new paper in the Proceedings of the National Academy of Sciences, released Monday, scientists tried to quantify how this “wildlife corridor” strategy might be used to slow extinction rates in two biodiversity hot spots, the Atlantic Forest of Brazil and the Eastern Arc Mountains of Tanzania…