Anthropogenic nitrogen (N) emission and subsequent N deposition have greatly affected the carbon (C) cycles of terrestrial ecosystems.

Researchers led by Dr. KUANG Yuanwen from South China Botanical Garden of Chinese Academy of Science found that canopy N addition significantly reduced soil organic carbon content and the macroaggregation fractions after seven-year’s treatment. The contribution of new carbon from the litter was more than two times with understory than with canopy N addition. They found that understory N addition significantly affected the activities of the extracellular enzymes while canopy N addition was not.

The results implied that forest canopy mitigates the effects of atmospheric N inputs on soil organic carbon, and suggested that conventional understory N addition might overestimate the positive effects of N deposition on forest soil carbon-related processes. Atmospheric N deposition may not greatly increase the accumulation of C in forest soils.

The study entitled “Canopy mitigates the effects of nitrogen deposition on soil carbon-related processes in a subtropical forest” was recently published in Science of the Total Environment. For further reading, please refer to: https://doi.org/10.1016/j.scitotenv.2020.143847.