Australia and South America need elephants to save their threatened native plants

March 18th, 2009 - 3:58 pm ICT by ANI  

Sydney, March 18 (ANI): An ecologist has said that large herbivores like elephants need to be introduced in regions such as Australia and South America, which would help save threatened native plants.

According to a report by ABC News, Professor Chris Johnson, of James Cook University, Far North Queensland, Australia, ecologist has called for the introduction of elephants into South America and the creation of Pleistocene parks across the world.

The re-introduction of large herbivores to the Americas would help restore ecosystems and save threatened native species, he said.

The experiment would also help settle the debate over whether humans or climate change caused megafauna, such as mammoths and giant kangaroos, to become extinct, he added.

The large animals maintained vegetation openness and in wooded landscapes created mosaics of different vegetation with a high diversity of plant species, according to Johnson.

However, the extinction of megafauna saw landscapes very quickly, in ecological terms, become dense and uniform, he added.

Johnson points to studies that show vegetation changed after the giant plant eaters became extinct and not, as is required under the climate change scenario, before.

He points to studies of ancient emu eggshells that show more than 50,000 years ago, the flightless bird had a broad diet that was a mixture of subtropical and arid grasses and shrubs, trees and temperate grasses.

Yet, by about 45,000 years, ago the birds diet no longer included subtropical and arid grasses .

It shows their foraging environment was once broad and diverse and that this contracted to a more uniform landscape, said Johnson. Climate cannot account for this change, he added.

According to Johnson, there are many plants that once interacted with the megafauna that still retain obsolete defences and ineffective methods of seed dispersal.

He said that reintroduction of large herbivores to regions where these plants still exist could help save them.

Johnson also believes that the creation of Pleistocene parks, where the original large mammals or their closest analogues are reintroduced, is feasible and essential to conserve biodiversity.

To understand living plant communities we need to re-imagine them with their full complement of Pleistocene megafauna, he said.

This insight should also provide the foundation for ecological restoration, which should aim to reinstate interactions between large herbivores and vegetation where that is still possible, he added. (ANI)

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