<
https://www.sciencealert.com/forest-islands-in-the-amazon-host-unique-ecosystems-but-theyre-doomed>
"Built in the 1980s, the Balbina Dam is one of dozens of large dams across
rivers in the Amazon Basin. Such dams might leave behind seemingly green
patches of forest, but our new research has shown these disconnected patches of
forest are no longer able to support thriving ecosystems.
The dam created one of the largest reservoirs in South America which stretches
for almost 100 kilometers northwards through largely undisturbed rainforest.
As this is a relatively hilly part of the Amazon basin, more than 3,500 islands
formed as the reservoir filled up. What were once ridges or hilltops became
insular forest patches.
For rainforest ecologists like us, the new landscape was an astonishing living
lab – a way to test theories of what happens when a forest and its many animals
are increasingly restricted to smaller and smaller patches.
We know that one of the main drivers of the ongoing biodiversity crisis is the
loss of habitat and the fragmentation of the remaining areas. And we know that
hydroelectric dams are one of the primary ways humans are disturbing these
habitats, and that many developing countries (including those in the Amazon)
are due to build many more dams.
In the new landscape created after a dam fragments the forest, we expect
species to disappear faster from smaller islands that simply can't sustain
viable populations. And we expect other factors to play a role, such as whether
a species is resilient and can cope with its habitat being transformed.
That's the theory, at least. And the Balbina Dam gave us a perfect chance to
see it in practice."
Via Rixty Dixet.
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
