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Mountain Plants Can’t Climb Higher

Many tropical mountain-top plants won’t survive global warming, even under the best-case climate scenario, according to modelling by James Cook University and Australian Tropical Herbarium researchers. “They already live on mountain tops; they have no other place to go,” said lead researcher Dr Craig Costion.

The scientists looked at 19 plant species in the tropics found at least 1000 metres above sea level. Modelling of three climate change scenarios in the region, ranging from conservative to extreme, found that by 2040 the climate niche the species grow in would decline anywhere between a minimum of 17% and a maximum of 100%. By 2080, even using conservative assumptions, nearly half of the plants would not have what the scientists believe is a survivable climate.

The data show that between 2040 and 2060 eight to 12 species will be at risk of extinction, and by 2080 no suitable habitat will exist within the region for 84% of the species studied under any emissions scenario.

“Our study indicates that the current climate on Queensland’s mountain-tops will virtually disappear,” Costion said. “What we don’t know is if these plants can adapt.”

The researchers looked only at endemic trees and shrubs found solely above 1000 metres and for which there were the best records. They didn’t consider reasons for their presence on mountaintops apart from climate suitability.

“The 19 species represent most of the plants that are restricted to that habitat. It’s highly likely they are found only there because of the climate. There are plenty of other similar soil and substrate environments at lower elevations where they could grow but the climate is unsuitable,” he said.

The research has been published in Biological Conservation.