Subscribe free to our newsletters via your
. Earth Science News .




WOOD PILE
Tree roots in the mountains 'acted like a thermostat' for millions of years
by Staff Writers
Oxford, UK (SPX) Feb 12, 2014


This is the valley in the Southern Peruvian Andes where fine root growth and organic layer thickness were measured over several years. Image courtesy Cecile Girardin.

For the first time, scientists have discovered how tree roots in the mountains may play an important role in controlling long-term global temperatures. Researchers from Oxford and Sheffield Universities have found that temperatures affect the thickness of the leaf litter and organic soil layers, as well as the rate at which the tree roots grow.

In a warmer world, this means that tree roots are more likely to grow into the mineral layer of the soil, breaking down rock into component parts which will eventually combine with carbon dioxide.

This process, called weathering, draws carbon dioxide out of the atmosphere and cools the planet. The researchers say this theory suggests that mountainous ecosystems have acted like the Earth's thermostat, addressing the risk of 'catastrophic' overheating or cooling over millions of years.

In their research paper published online in Geophysical Research Letters, the researchers carried out studies in tropical rain forests in Peru, measuring tree roots across different sites of varying altitude - from the warm Amazonian Lowlands to the cooler mountain ranges of the Andes. They measured the growth of the tree roots to 30 cm beneath the surface, every three months over several years.

At each of the sites, they also measured the thickness of the organic layer above the soil. This information was then combined with existing data of monthly temperature, humidity, rainfall, and soil moisture in order to calculate the likely breakdown process of the basalt and granite rocks found in the mountain ranges of Peru.

Using this model, based on field data in Peru, the scientists were able to scale up in order to calculate the likely contribution of mountain forests worldwide to global weathering rates.

The researchers then calculated the likely amount of carbon to be pulled out of the atmosphere through weathering when the Earth became very hot. They looked at the volcanic eruptions in India 65 million years ago (known as the Deccan traps).

The model also allowed them to calculate the weathering process and carbon feedback after the Earth's cooling 45 million years ago, when great mountain ranges like the Andes and the Himalayas were first formed.

The paper suggests that mountainous regions may play a particularly important role in drawing carbon out of the atmosphere because they have abundant volcanic rock which is highly reactive to weathering when it disintegrates.

Lead researcher Chris Doughty, from the School of Geography and the Environment at the University of Oxford, said: "This is a simple process driven by tree root growth and the decomposition of organic material. Yet it may contribute to Earth's long-term climate stability. It seems to act like a thermostat, drawing more carbon dioxide out of the atmosphere when it is warm and less when it is cooler.

"A series of climatic events over the last 65 million years ago have resulted in global temperatures rising and falling. However, the weathering process that regulates carbon dioxide in the atmosphere may be buffered by forests that grow in mountainous parts of the world. In the past, this natural process may have prevented the planet from reaching temperatures that are catastrophic for life."

The paper 'Montane forest root growth and soil organic layer depth as potential factors stabilizing Cenozoic global change' is published online in Geophysical Research Letters on 6 February 2014.

.


Related Links
University of Oxford
Forestry News - Global and Local News, Science and Application






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








WOOD PILE
NASA Study Points to Infrared-Herring in Apparent Amazon Green-Up
Greenbelt MD (SPX) Feb 11, 2014
For the past eight years, scientists have been working to make sense of why some satellite data seemed to show the Amazon rain forest "greening-up" during the region's dry season each year from June to October. The green-up indicated productive, thriving vegetation in spite of limited rainfall. Now, a new NASA study published in the journal Nature shows that the appearance of canopy greeni ... read more


WOOD PILE
165,000 without power in storm-battered Ireland

Beckham gives cheer in Philippines typhoon zone

Study highlights indigenous response to natural disaster

Bottom-up insight into crowd dynamics

WOOD PILE
Data links quick fix

China gold consumption leaps 41% in 2013

Towards tailor-made adhesives

MDA announces Canada's DND Sapphire satellite completes commissioning

WOOD PILE
Fiji leader invites climate-hit Kiribati residents to relocate

Meeting the eye-witnesses of ocean change

Israelis fume over EU parliament president 's water remark

Fish living near the equator will not thrive in the warmer oceans of the future

WOOD PILE
China's Antarctic explorations peacefully intended, cooperative

Ice age's arctic tundra lush with wildflowers for woolly mammoths

Chinese sailors throw bottles into Antarctic Ocean: report

Research gives new insight into diet of large ancient mammals

WOOD PILE
Danone says will double stake in Chinese milk firm Mengniu

New GM corn gets controversial EU go-ahead

Brazil soy, corn production overcome drought

Polish woman guilty of killing two million bees: court

WOOD PILE
Indonesia orders 200,000 to evacuate as volcano erupts

Storms, high winds batter flooded parts of Britain

Not yet tame: River Thames shows its power

Magnitude 6.8 earthquake strikes China's Xinjiang: USGS

WOOD PILE
Poaching threatens savannah ecosystems

French defence chief urges crackdown on C.Africa militias

South Sudan peace talks postponed: officials

C. Africa militia is 'enemy of peace': French commander

WOOD PILE
Mobile apps shake up world of dating

Population bomb may be defused, but research reveals ticking household bomb

The genetic origins of high-altitude adaptations in Tibetans

New twists for love in age of big data




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement