Can Meadows Rescue the Planet from CO2?Leave a Comment
By Jane Braxton Little on May 11, 2017 Scientific American
…Scientists and land managers are heading into the mountains to measure the greenhouse gas activity at 16 hand-picked meadows—some recently restored, others degraded from a century of grazing and logging.
The four-year study is part of California’s pioneering effort to reduce carbon emissions. The project is designed to determine whether restored meadows hold more carbon than those that have been degraded. The outcome could prove pivotal for California and the planet. Worldwide, soils store three times more carbon than vegetation and the atmosphere combined. If the research shows restored meadows improve carbon storage, it could stimulate meadow restoration around the world….
…A December study published in Nature… found rising temperatures are stimulating a net loss of soil carbon to the atmosphere. Warmer soils accelerate the flux, sending more carbon into the ground and more carbon dioxide back out into the atmosphere. As warmth increases microbial activity, decomposition and respiration outpace photosynthesis, particularly in the world’s colder places. …” The changes could drive a carbon–climate feedback loop that could accelerate climate change.”…
…The research covers meadows from the base of Lassen Peak in the north to areas nearer to Los Angeles. The meadows range in elevation from 3,045 to nearly 8,700 feet; they include granitic, volcanic and metamorphic soils. A critical facet of the partnership is developing precise procedures for when and how to measure and analyze meadow greenhouse gases.
……a limited study conducted by the University of Nevada, Reno (U.N.R.). Scientists collected soil samples at seven meadows in the northern Sierra restored between 2001 and 2016, pairing restored sites with similar, adjacent unrestored sites….found an average of 20 percent more soil carbon in restored meadows, with one site recording an increase of over 80 percent. Meadows immediately begin storing carbon following restoration, with significant increases over 15 years, says Cody Reed, a research assistant working with Ben Sullivan, a U.N.R. soil scientist and assistant professor. The investigation seems to show restored meadows add soil carbon and also slow losses to the atmosphere.
…[In another study] they found surprised them: Carbon dioxide emissions were unaffected by soil moisture content, and methane sequestration was prevalent, particularly on the dry side of wet meadow. The 2014 study also found plant species richness and soil carbon concentration appeared more important than soil moisture in explaining carbon fluxes.