New Study Reveals Unexpected Soil Carbon Response to Nitrogen and Warming

A recent study reveals the nuanced relationship between warmer temperatures and increased nitrogen deposits in forest soils, both of which are influenced by fossil fuel emissions. Published in Nature Ecology & Evolution, the study was led by University of New Hampshire researchers Melissa Knorr and Serita Frey (the latter also being a Harvard Forest Research Associate). Leveraging over 16 years of data collected at the Harvard Forest, the study reveals a better understanding of how these two factors influence the storage of carbon in forest soils of the northeast.

Harvard Forest's extensive long-term data repository and unique field site allowed the researchers to expand upon previous research, which had only studied the impacts of each factor independently, to include how different climate-driven processes occur together. To their surprise, Frey and Knorr found that when warmer temperatures and increased nitrogen levels were both present in soil simultaneously, the amount of carbon stored in the soil remained stable. This finding counters previous research, implying that forest soils in the northeast might be capable of storing more carbon than formerly predicted. 

While the findings certainly hold global significance, they are particularly relevant to the northeast, where increased temperatures and historically elevated nitrogen deposition have both influenced forests. An increased understanding of plant-soil interactions is integral to ensuring that forests remain carbon sinks, reducing the concentration of CO₂ in the atmosphere.

Read more at the University of New Hampshire's press release.