Researchers say tree roots act as thermostat for global climate

LONDON, Feb. 6 (UPI) -- For millions of years, tree roots in mountainous regions have been doing their best -- new science suggests -- to regulate the global climate, keeping Earth's atmosphere from growing too hot or too cold.

Scientists at Oxford and Sheffield Universities realized that hotter temperatures encouraged trees to grow thinner leaves, thus softening the composition of soil layers. Hot temperatures also spur tree roots grow faster.

With softer soil, faster, deeper growing roots are able to more quickly and efficiently break up rocks and minerals below, scientists concluded, facilitating a process called "weathering," whereby broken down materials combine with carbon dioxide. Weathering helps pull carbon dioxide out the atmosphere and cool the planet.

"This study shows how trees can act as brakes on extreme climate change, and the roots of trees in tropical mountains such as the Andes play a disproportionate role," co-author Yadvinder Malhi, Professor of Ecosystem Science at Oxford University, said.

Scientists -- who studied a range of different roots in the Andes -- think the tree roots in mountainous regions play the biggest role as climate stabilizer because of the abundance of volcanic material in the soil, which is particularly reactive to weathering.

While the revelations have moved scientists to term tree roots "Earth's thermostat," the process is much slower than the almost immediate results of a modern AC unit.

"These responses take thousands to millions of years," warned Malhi, "and cannot do much to slow the rate of global warming we are experiencing this century."

[Oxford University] [Science Daily]