Friday, June 22, 2012

Studying soil to predict the future of earth's atmosphere

Brigham Young University: When it comes to understanding climate change, it’s all about the dirt. A new study by researchers at BYU, Duke and the USDA finds that soil plays an important role in controlling the planet’s atmospheric future.

The researchers set out to find how intact ecosystems are responding to increased levels of carbon dioxide in the atmosphere. The earth’s current atmospheric carbon dioxide is 390 parts per million, up from 260 parts per million at the start of the industrial revolution, and will likely rise to more than 500 parts per million in the coming decades.

What they found, published in the current issue of Nature Climate Change, is that the interaction between plants and soils controls how ecosystems respond to rising levels of CO2 in the atmosphere. “As we forecast what the future is going to look like, with the way we’ve changed the global atmosphere, often times we overlook soil,” said BYU biology professor Richard Gill, a coauthor on the study. “The soils matter enormously and the feedbacks that occur in the soil are ultimately going to control the atmosphere.”

The research shows that even in the absence of climate change, humans are impacting vital ecosystems as the composition of the earth’s atmosphere changes. They observed that changes in atmospheric CO2 caused changes in plant species composition and the availability of water and nitrogen. Researchers worry that if the ability of plants and soils to absorb carbon becomes saturated over time then CO2 in the atmosphere will increase much more quickly than it has in the past.

“We don’t just have to be concerned about climate change, we have to be concerned about the other changes in atmospheric chemistry,” Gill said. “Globally we’re changing the earth’s atmosphere and we know that is going to influence the systems we depend on. To forecast those changes, you have to understand deeply what is happening in soils.”...

Undergraduate Sarah Karlinsey measures photosynthesis levels at a site near Ephraim, Utah. From the BYU website

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