Ecosystem ecology studies often focus on what’s happening to plants above ground, for instance exploring photosynthesis or water loss in leaves. But what is happening below the ground in plant roots is equally important when evaluating ecosystem processes.
In a new study in Nature Geoscience researchers in the Department of Organismic and Evolutionary Biology at Harvard University examined root exudates and their impact on soil carbon storage revealing surprising and counterintuitive results.
Root exudates are organic carbon compounds (such as simple sugars, organic acids, and amino acids) released from living plant roots into the soil. These small molecules can bind directly to soil minerals, making them important regulators of soil carbon formation and loss. Unlike plant litter (such as leaves and roots), which must be decomposed before it can affect the soil carbon pool, root exudates can have immediate effects on mineral-associated organic matter (MAOM), which contains long-cycling, “stable” soil carbon.
Several studies show that anthropogenically elevated atmospheric CO2 concentrations are likely to increase the rate of plant root exudation and change the chemical composition of root exudates. Lead author Nikhil R. Chari, Ph.D. candidate, and senior author Professor Benton N. Taylor tested how these changes may affect soil carbon by examining how changing the rate of root exudation and the composition of exudates affected native soil-carbon dynamics in a temperate forest.
Read more at Harvard University, Department of Organismic and Evolutionary Biology
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