Climate change decreases nitrogen pools and mineralization rates in northern hardwood forests
Jorge Durán,
Jennifer L. Morse,
Peter M. Groffman,
John L. Campbell,
Lynn M. Christenson,
Charles T. Driscoll,
Timothy J. Fahey,
Melany C. Fisk,
Gene E. Likens,
Jerry M. Melillo,
Myron J. Mitchell,
Pamela H. Templer,
Matthew A. Vadeboncoeur
Affiliations
Jorge Durán
Cary Institute of Ecosystem Studies 2801 Sharon Turnpike Millbrook New York 12545 USA
Jennifer L. Morse
Environmental Science and Management Portland State University PO Box 751 (ESM) Portland Oregon 97207 USA
Peter M. Groffman
Cary Institute of Ecosystem Studies 2801 Sharon Turnpike Millbrook New York 12545 USA
John L. Campbell
Northern Research Station USDA Forest Service 271 Mast Road Durham New Hampshire 03824 USA
Lynn M. Christenson
Biology Department Vassar College 124 Raymond Ave. Poughkeepsie New York 12604 USA
Charles T. Driscoll
Department of Civil and Environmental Engineering Syracuse University 900 S Crouse Ave Syracuse New York 13210 USA
Timothy J. Fahey
Department of Natural Resources Cornell University Ithaca New York 14850 USA
Melany C. Fisk
Department of Zoology Miami University 501 E High St Oxford Ohio 45056 USA
Gene E. Likens
Cary Institute of Ecosystem Studies 2801 Sharon Turnpike Millbrook New York 12545 USA
Jerry M. Melillo
Marine Ecological Laboratory The Ecosystem Center Woods Hole Massachusetts 02543 USA
Myron J. Mitchell
Department of Environmental and Forest Biology SUNY‐College of Environmental Science and Forestry 1 Forestry Dr Syracuse New York 13210 USA
Pamela H. Templer
Department of Biology Boston University 5 Cummington Street Boston Massachusetts 02215 USA
Matthew A. Vadeboncoeur
Institute for the Study of Earth, Oceans and Space Earth Systems Research Center University of New Hampshire 8 College Road Durham New Hampshire 03824 USA
Abstract Nitrogen (N) supply often limits the productivity of temperate forests and is regulated by a complex mix of biological and climatic drivers. In excess, N is linked to a variety of soil, water, and air pollution issues. Here, we use results from an elevation gradient study and historical data from the long‐term Hubbard Brook Ecosystem Study (New Hampshire, USA) to examine relationships between changes in climate, especially during winter, and N supply to northern hardwood forest ecosystems. Low elevation plots with less snow, more soil freezing, and more freeze/thaw cycles supported lower rates of N mineralization than high elevation plots, despite having higher soil temperatures and no consistent differences in soil moisture during the growing season. These results are consistent with historical analyses showing decreases in rates of soil N mineralization and inorganic N concentrations since 1973 that are correlated with long‐term increases in mean annual temperature, decreases in annual snow accumulation, and a increases in the number of winter thawing degree days. This evidence suggests that changing climate may be driving decreases in the availability of a key nutrient in northern hardwood forests, which could decrease ecosystem production but have positive effects on environmental consequences of excess N.
