The shore of a sea of nearly 400 billion trees winds through the central Brazilian state of Mato Grosso. Here, the Amazon rainforest rubs up against the Cerrado, the world’s largest savanna.
“But in this formula is a new element,” says ecologist Beatriz Marimon of Mato Grosso State University in Nova Xavantina. Humans, with their ambitions to domesticate the land, she says.
About half a century ago, throngs of people started streaming into the region along new highways, clearing forest for farmland and cattle ranches, she says. Fifty years is a blink in the life span of a forest nearly as old as the dinosaurs, but it’s plenty of time for humans to remodel a landscape.
In 2007, earth system scientist Carlos Nobre, now at the University of São Paulo, and his colleagues suggested that much of the Amazon could transform into a savanna if deforestation exceeded 40 percent of the forest’s original area, which was mostly whole before the 1970s.
2023-06-16 09:00:00
Original from www.sciencenews.org