The collaborative study indicates that the meadows are promising to help control the carbon released into the atmosphere
Credit: Photography by CC Reed, University of Nevada, Reno.
Renault, Nev. Meadows in the Sierra Nevada Mountains are essential components of a watershed. In addition to providing water to more than 25 million people in California and Nevada, lawns contain large amounts of carbon underground. While it has been known for some time that meadows contain large amounts of carbon in the soil, whether meadowl soils gain or lose carbon remains unclear.
A new study led by researchers in the College of Agriculture, Biotechnology and Natural Resources at the University of Nevada, Reno, shows for the first time that lawns across the region are gaining and losing carbon at a high rate. Soil carbon capture and storage is a natural way to reduce carbon dioxide levels in the atmosphere and combat climate change. However, human activities can disrupt natural processes and lead to a loss of soil carbon to the atmosphere. These results indicate that lawn management may contribute to climate change or mitigate the harmful effects of increased carbon dioxide in the atmosphere.
The research was conducted in partnership with the University of California Merced, as well as various restoration practitioners and conservation organizations in more than a dozen meadows throughout the Sierra Nevada Mountains. The study aims to arm recovery practitioners with information to help make good management decisions.
“The meadows are known for their lush and varied plants that support soils that stay moist in the summer,” said Cody Reed, a doctoral candidate at the University of Nevada who led the study. “However, the long history of human activity on many meadows across the Sierra Nevada has resulted in drier soils and the replacement of wetland vegetation with sparse weeds and shrubs.”
In research published in the scientific journal this week Ecological systemsReed and her colleagues, including associate professors Benjamin Sullivan and Paul Verburg and Emeritus Professor Sherman Swanson of the university, revealed that meadows with wetland plant communities and dense root mats were large net carbon pools during the year measured, which means they removed carbon from Atmosphere. In fact, per acre, the amount of carbon captured in these meadows was comparable to the rates measured in tropical rainforests. On the other hand, meadows with bare lands and plant communities associated with drier soils release large amounts of carbon from the soil into the atmosphere.
In the long term, such changes can build up to large soil carbon stocks in meadows. And unlike forests, where most of the carbon is sequestered in wood above ground, the change in carbon in meadows is underground. This means that grassland soil carbon is less prone to disturbances such as forest fires and may persist in the ecosystem for longer than above ground carbon. At the same time, soil carbon provides other important benefits besides taking carbon out of the atmosphere.
“Around the world, soil may contain up to four times the amount of carbon in the atmosphere,” Reid said. Soil carbon in lawns also helps improve water quality and quantity, as well as soil fertility to support diverse plant communities important for wildlife and grazing.
The research is likely to help lawn restoration practitioners identify lawns that need maintenance to maintain carbon gains in soils and lawns that need restoration to prevent additional losses of soil carbon in the atmosphere. Researchers estimate that three acres of surrounding forest are needed to replace the amount of carbon lost for one acre of degraded prairie. On the other hand, one acre of meadow might contain as much as six acres of forest.
“Our research shows that the promoter may be one of the best promoters for carbon management in the region,” said Sullivan. “It is my hope that soil carbon sequestration can be combined with other objectives to achieve management strategies that improve ecosystem functions in prairies.”
Sullivan said he and colleagues in the college’s Department of Natural Resources and Environmental Sciences and the experimental plant plan to conduct future research to determine the effects of lawn restoration on soil carbon.