Wat. Resour. Res. http://doi.org/hx2 (2012)

The effects of climate change, atmospheric carbon dioxide and atmospheric deposition on the hydrology and water quality of watersheds are potentially important for the continued provision of many ecosystem services, from biodiversity and amenity value to freshwater resources. Investigating these interacting effects is, however, a difficult task.

Afshin Pourmokhtarian, from the Department of Civil and Environmental Engineering, Syracuse University, USA, and co-workers used a hydrochemical model to evaluate the effects of potential future changes in temperature, precipitation, solar radiation and atmospheric carbon dioxide on major chemical elements at the Hubbard Brook Experimental Forest in New Hampshire, USA over the twenty-first century.

Model simulations under climate change displayed a shift in hydrology characterized by later snowpack development, earlier spring snowmelt, greater evapotranspiration and a slight increase in annual water yield. Under elevated temperature, net soil nitrogen mineralization and nitrification was simulated to increase markedly, resulting in acidification of soil and stream water and altering the quality of water draining from forested watersheds. However, the authors note that invoking a carbon dioxide fertilization effect on vegetation can substantially mitigate watershed nitrogen loss, highlighting the need for a more thorough understanding of carbon dioxide effects on forest vegetation.