Tag Archives: alan tessier

Scientists Reconstruct Pre-Columbian Human Effects on the Amazon Basin

Findings overturn idea that the Amazon had large populations of humans that transformed the landscape

Small, shifting human populations existed in the Amazon before the arrival of Europeans, with little long-term effect on the forest.

That’s the result of research led by Crystal McMichael and Mark Bush of the Florida Institute of Technology (FIT). The finding overturns the idea the Amazon was a cultural parkland in pre-Columbian times with large human populations that transformed vast tracts of the landscape.

The Amazon Basin is one of the highest biodiversity areas on Earth. Understanding how it was modified by humans in the past is important for conservation and for understanding the ecological processes in tropical rainforests. (more…)

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A River Ran Through It

About the image: A now dry Colorado River delta branches into the Baja/Sonoran Desert near the Sea of Cortez. Image credit: Pete McBride

Rivers and streams supply the lifeblood to ecosystems across the globe, providing water for drinking and irrigation for humans as well as a wide array of life forms from single-celled organisms up to the fish humans eat.

But humans and nature itself are making it tough on rivers to continue in their central role to support fish species, according to new research by a team of scientists including John Sabo, a biologist at Arizona State University.

Globally, rivers and streams are being drained due to human use and climate change. These and other human impacts alter the natural variability of river flows.

Some affected rivers have dried and no longer run, while others have seen increases in the variability of flows due to storm floods. (more…)

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