Species turn refugees to escape climate extremes
Nov 20, 2013: - Species threatened by climate change may turn into refugees and seek refuge from the heat in small habitats within rainforests.
A new study published today in Global Change Biology shows that small habitats within rainforest vegetation should provide relief from extreme temperatures.
Lead researcher Brett Scheffers from James Cook University in Townsville, Australia, said that while such habitats were small in size they provide big returns for the species that use them.
“These small habitats, known as microhabitats, include tree holes, logs, and plants that exist within the rainforest strata and they provide cooler temperatures within them than the air that surrounds them,” Mr Scheffers, from JCU’s Centre for Tropical Biology and Climate Change, said.
“In some ways these habitats serve as refuges for refugees. The refugees here are species that have to flee their normal habitats because the habitats are no longer livable.
“With climate change, commonly used habitats are simply becoming too hot.”
The co-authors of the study looked at the climate within numerous microhabitats located from ground to the upper canopy in the rainforests of the Philippines. They compared these climates to the surrounding environment as well as the thermal limits of frogs and reptiles that frequently use them.
The authors found that buffered microhabitats can reduce the vulnerability of animal communities to extreme events by over 100-fold.
“Although this study offers a glimmer of hope that species may be able to escape the heat we are urging caution,” Mr Scheffers said, “because extreme events are incredibly unpredictable and may be more extreme than the temperatures we considered in our study”.
There have been numerous examples of widespread death of animals that could not find refuge.
“For example, during recent heat waves across Australia, bat species such as flying-foxes and birds species such as Carnaby’s Cockatoos died by the hundreds and possibly thousands,” he said.
“Animals are adapted for specific temperatures.”
The study, involving researchers from JCU, the National University of Singapore, the University of Sheffield and the National Museum of the Philippines, shows that animals may be able to hide-out under short-term heat waves but ultimately as annual temperatures continue to rise animals will be forced to flee to cooler areas.
“Our study is a cautionary tale. Biodiversity is resilient and adaptive,” Mr Scheffers said.
“However, with future forecasts predicting annual temperature increases of up to 4-6 degrees Celsius and in some areas extreme temperatures that surpass 40 degrees Celsius, there are simply no habitats cool enough to safeguards species from such extremes.”
Microhabitats reduce animal’s exposure to climate extremes
Brett R. Scheffers, David P. Edwards, Arvin Diesmos, Stephen E. Williams, Theodore A. Evans
Contact: Brett Scheffers
JCU Media: Jim O’Brien +61 7 4781 4822 or 0418 892449
Issued: November 20, 2013