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Dr. Peter M. Groffman

Microbial Ecologist | PhD, University of Georgia

Expertise
soil ecology, water quality

Profile (pdf)

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Peter Groffman studies how microbial processes impact gas exchange - particularly nitrogen - between the soil and air. His work encompasses rural and urban ecosystems, and is primarily centered at two of the National Science Foundation’s Long Term Ecological Research sites located in Hubbard Brook, New Hampshire and Baltimore, Maryland.

As a result of climate change, forests in the northeastern US are experiencing reduced winter snow cover. This change leaves the forest soil exposed to subfreezing temperatures for extended periods. Without a layer of insulating snow, important biological activity that usually continues throughout the winter stops. Freezing damages tender tree roots. Increased winter rain washes nitrogen and phosphorus - nutrients critical to tree growth - out of the soil, threatening forest productivity and water quality. Bare soils produce more nitrous oxide and consume less methane - both potent greenhouse gases. Understanding these processes will inform forest management as climate warms.

Urbanization is a global trend marked by increasing homogenization of the landscape; imagine the cookie cutter properties that characterize ‘suburbia’. Understanding landscape homogenization will help predict the impacts of urban land use change and its effects on carbon storage and nitrogen pollution, on multiple spatial scales.

Groffman was a Convening Lead Author for the third National Climate Assessment Chapter on Ecosystems, Biodiversity and Ecosystem Services.

Groffman is also a Professor at the City University of New York Advanced Science Research Center at the Graduate Center and the Brooklyn College Department of Earth and Environmental Sciences.

Morse, Jennifer L., Jorge Durán, and Peter M. Groffman. 2015. “Soil Denitrification Fluxes in a Northern Hardwood Forest: The Importance of Snowmelt and Implications for Ecosystem N Budgets”. Ecosystems 18 (3): 520-32. doi:10.1007/s10021-015-9844-2.
Ewing, Holly A., Amy R. Tuininga, Peter M. Groffman, Kathleen C. Weathers, Timothy J. Fahey, Melany C. Fisk, Patrick J. Bohlen, and Esteban R. Suárez. 2015. “Earthworms Reduce Biotic 15-Nitrogen Retention in Northern Hardwood Forests”. Ecosystems 18 (2): 328-42. doi:10.1007/s10021-014-9831-z.
van Groenigen, J. W., D. Huygens, P. Boeckx, Th. W. Kuyper, I. M. Lubbers, T. Rütting, and Peter M. Groffman. 2015. “The Soil N Cycle: New Insights and Key Challenges”. SOIL 1 (1): 235-56. doi:10.5194/soil-1-235-2015.
Larson, Kelli L., Kristen C. Nelson, S. R. Samples, Sharon J. Hall, Neil D. Bettez, Jeannine Cavender-Bares, Peter M. Groffman, et al. 2015. “Ecosystem Services in Managing Residential Landscapes: Priorities, Value Dimensions, and Cross-Regional Patterns”. Urban Ecosystems. doi:10.1007/s11252-015-0477-1.
Ballantine, Katherine, Johannes Lehmann, Rebecca Schneider, and Peter M. Groffman. 2015. “Trade-Offs Between Soil-Based Functions in Wetlands Restored With Soil Amendments of Differing Lability”. Ecological Applications, 140625210517000. doi:10.1890/13-1409.1.
Balaria, Ankit, Chris E. Johnson, Peter M. Groffman, and Melany C. Fisk. 2015. “Effects of Calcium Silicate Treatment on the Composition of Forest Floor Organic Matter in a Northern Hardwood Forest Stand”. Biogeochemistry 122 (2-3): 313-26. doi:10.1007/s10533-014-0043-6.
Anderson, Todd R., Peter M. Groffman, and Todd Walter. 2015. “Using a Soil Topographic Index to Distribute Denitrification Fluxes across a Northeastern Headwater Catchment”. Journal of Hydrology 522: 123-34. doi:10.1016/j.jhydrol.2014.12.043.
McPhillips, Lauren E., Peter M. Groffman, Christine L. Goodale, and Todd Walter. 2015. “Hydrologic and Biogeochemical Drivers of Riparian Denitrification in an Agricultural Watershed”. Water, Air, & Soil Pollution 226 (6). doi:10.1007/s11270-015-2434-2.
Yavitt, Joseph B., Timothy J. Fahey, Ruth E. Sherman, and Peter M. Groffman. 2015. “Lumbricid Earthworm Effects on Incorporation of Root and Leaf Litter into Aggregates in a Forest Soil, New York State”. Biogeochemistry 125 (2): 261-73. doi:10.1007/s10533-015-0126-z.
Beier, C. M., Jesse Caputo, and Peter M. Groffman. 2015. “Measuring Ecosystem Capacity to Provide Regulating Services: Forest Removal and Recovery at Hubbard Brook (USA)”. Ecological Applications, 150317095027002. doi:10.1890/14-1376.1.
Duncan, Jonathan M., Lawrence E. Band, Peter M. Groffman, and Emily S. Bernhardt. 2015. “Mechanisms Driving the Seasonality of Catchment Scale Nitrate Export: Evidence for Riparian Ecohydrologic Controls”. Water Resources Research 51 (6): 3982-97. doi:10.1002/wrcr.v51.610.1002/2015WR016937.
Morillas, Lourdes, Jorge Durán, Alexandra Rodríguez, Javier Roales, Antonio Gallardo, Gary M. Lovett, and Peter M. Groffman. 2015. “Nitrogen Supply Modulates the Effect of Changes in Drying-Rewetting Frequency on Soil C and N Cycling and Greenhouse Gas Exchange”. Global Change Biology 21 (10): 3854-63. doi:10.1111/gcb.12956.
Lazar, Julia G., Kelly Addy, Arthur J. Gold, Peter M. Groffman, R. McKinney, and D.Q. Kellogg. 2015. “Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States”. Journal of Environment Quality. doi:10.2134/jeq2014.12.0540.
Hickman, Jonathan E., Katherine L. Tully, Peter M. Groffman, Willy Diru, and Cheryl A. Palm. 2015. “A Potential Tipping Point in Tropical Agriculture: Avoiding Rapid Increases in Nitrous Oxide Fluxes from Agricultural Intensification in Kenya”. Journal of Geophysical Research: Biogeosciences 120 (5): 938-51. doi:10.1002/2015JG002913.
Bettez, Neil D., Jonathan M. Duncan, Peter M. Groffman, Lawrence E. Band, Jarlath O’Neil-Dunne, Sujay S. Kaushal, Kenneth T Belt, and N. Law. 2015. “Climate Variation Overwhelms Efforts to Reduce Nitrogen Delivery to Coastal Waters”. Ecosystems 18 (8): 1319-31. doi:10.1007/s10021-015-9902-9.
Anderson, Todd R., Christine L. Goodale, Peter M. Groffman, and Todd Walter. 2014. “Assessing Denitrification from Seasonally Saturated Soils in an Agricultural Landscape: A Farm-Scale Mass-Balance Approach”. Agriculture, Ecosystems & Environment 189: 60-69. doi:10.1016/j.agee.2014.03.026.
Lazar, Julia G., Arthur J. Gold, Kelly Addy, Paul M. Mayer, Kenneth Forshay, and Peter M. Groffman. 2014. “Instream Large Wood: Denitrification Hotspots With Low N2O Production”. JAWRA Journal of the American Water Resources Association 50 (3): 615-25. doi:10.1111/jawr.2014.50.issue-310.1111/jawr.12202.
Polsky, Colin, Morgan Grove, C. Knudson, Peter M. Groffman, Neil D. Bettez, Jeannine Cavender-Bares, Sharon J. Hall, et al. 2014. “Assessing the Homogenization of Urban Land Management With an Application to US Residential Lawn Care”. Proceedings of the National Academy of Sciences 111 (12): 4432-37. doi:10.1073/pnas.1323995111.
Wexler, Sarah K., Christine L. Goodale, K. J. McGuire, Scott W. Bailey, and Peter M. Groffman. 2014. “Isotopic Signals of Summer Denitrification in a Northern Hardwood Forested Catchment”. Proceedings of the National Academy of Sciences 111 (46): 16413-18. doi:10.1073/pnas.1404321111.
Christenson, Lynn M., Myron J. Mitchell, Peter M. Groffman, and Gary M. Lovett. 2014. “Cascading Effects of Climate Change on Forest Ecosystems: Biogeochemical Links Between Trees and Moose in the Northeast USA”. Ecosystems 17 (3): 442-57. doi:10.1007/s10021-013-9733-5.