Soil warming, carbon-nitrogen interactions, and forest carbon budgets

TitleSoil warming, carbon-nitrogen interactions, and forest carbon budgets
Publication TypeJournal Article
Year of Publication2011
AuthorsMelillo, Jerry M., Butler S., Johnson J., Mohan J., Steudler P., Lux H., Burrows E., Bowles F., Smith R., Scott L., Vario C., Hill T. D., Burton A., Zhou Y.-M., and TANG JIANWU
JournalProceedings of the National Academy of Sciences
Pagination9508 - 9512
Date Published06/2011
Keywordsclimate system feedbacks, ecological stoichiometry, forest carbon budget, forest nitrogen budget, global climate change

Soil warming has the potential to alter both soil and plant pro- cesses that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumula- tive net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming- induced increases in nitrogen availability. This study underscores the importance of incorporating carbon–nitrogen interactions in atmosphere–ocean–land earth system models to accurately simu- late land feedbacks to the climate system.