Nitrogen Saturation
The chronic deposition of nitrogen from the atmosphere is a recent stress to New England forests resulting from the combustion of fossil fuels. Nitrogen is a limiting nutrient to most terrestrial ecosystems, but may be a pollutant in aquatic ecosystems and drinking water. Therefore there are many fundamental and applied questions regarding the impact of long-term additions of nitrogen to our landscape. We have investigated the long-term response of nitrogen-limited forests to this novel disturbance since 1990. Two stands (red pine and mixed hardwood) have been given fertilizer N applications that are one and three times the current atmospheric N deposition in central Europe. Measured field processes include:
- net N mineralization
- net nitrification
- N leaching
- litter fall
- aboveground NPP
- fine-root turnover
- foliar chemistry
- soil fluxes of CH4, N2O, and CO2
In 1991 and 1992 we added 15N-labeled ammonium and nitrate separately to half of each control and low N plot to follow the movements of added N into soil and vegetation.
Further Information: http://www.aber.sr.unh.edu/chronicn/hfintro.html
Publications:
Aitkenhead-Peterson, J. A., G. M. Bernston, W. H. McDowell, and J. D. Aber. 2005. Chronic carbon and nitrogen manipulation:effect on the relationships between soil C:N, soil respiration and soil solutation DOC in temperate forests. Soil Biology and Biochemistry (Accepted).
Venterea, R. T., P.M. Groffman, L.V. Verchot, A.H. Magill, and J.D. Aber. 2004. Gross nitrogen process rates in temperate forest soils exhibiting symptoms of nitrogen saturation. Forest Ecology and Management 196: 129-142.
Nadelhoffer, K. J., B. P. Colman, W. S. Currie, A. H. Magill, and J. D. Aber. 2004. Decadal scale fates of 15N tracers added to oak and pine stands under ambient and elevated N inputs at the Harvard Forest (USA). Forest Ecology and Management 196: 89-107.
Micks, P., M. R. Downs, A. H. Magill, K. J. Nadelhoffer, and J. D. Aber. 2004. Decomposing litter as a sink for 15N-enriched additions to an oak forest and a red pine plantation. Forest Ecology and Management 196: 71-87.
Micks, P., J. D. Aber, R. D. Boone, and E. A. Davidson. 2004. Short-term soil respiration and nitrogen immobiliation response to nitrogen applications in control and nitrogen-enriched temperate forests. Forest Ecology and Management 196: 57-70.
McDowell, W. H., A. Magill, J. A. Aikenhead-Peterson, J. D. Aber, J. L. Merriam, and S. S. Kaushal. 2004. Effects of chronic nitogen amendment on dissolved organic matter and inorganic nitrogen soil solution. Forest Ecology and Management 196: 29-41.
Magill, A. H., J. D. Aber, W. S. Currie, K. J. Nadelhoffer, M. E. Martin, W. H. McDowell, J. M. Melillo, and P. Steudler. 2004. Ecosystem Response to 15 years of Chronic Nitrogen Additions at the Harvard Forest LTER, Massachusetts, USA. Forest Ecology and Management 196: 7-28.
Frey, S. D., M. Knorr, J. L. Parrent, and R. T. Simpson. 2004. Chronic nitrogen enrichment affects the structure and function of the soil microbial community in temperate hardwood and pine forests. Forest Ecology and Management 196: 159-171.
Foster, D., J. Aber, R. Bowden, J. Melillo, and F. Bazzaz. 2004. Comparison between physical disturbance and novel stresses. Pp. 296-299 In D. Foster and J. Aber (Eds.), Forests in Time: The Environmental Consequences of 1000 Years of Change in New England. Yale University Press, New Haven, CT.
Foster, D. and J. Aber. (Eds) 2004. Forests in Time: The Environmental Consequences of 1000 Years of Change in New England . Yale University Press, New Haven, CT.
Currie, W. S., K. J. Nadelhoffer, and J. D. Aber. 2004. Redistributions of 15N highlight turnover and replishment of mineral soil organic N as a long-term control on forest C balance. Forest Ecology and Management 196: 109-127.
Compton, J. E., L. S. Watrud, L. A. Porteous, and S. DeGrood*. 2004. Response of Soil Microbial Biomass and Community Composition to Chronic Nitrogen Additions at Harvard Forest. Forest Ecology and Management 196: 143-158.
Bowden, R. D., E. Davidson, K. Savage, C. Arabia*, and P. Steudler. 2004. Chronic nitrogen additions reduce total soil respiration and microbial respiration in temperate forest soils at the Harvard Forest. Forest Ecology and Management 196: 3-56.
Bauer, G. A., F. A. Bazzaz, R. Minocha, S. Long, A. Magill, J. Aber, and G. M. Berntson. 2004. Effects of chronic N additions on tissue chemistry, photosynthetic capacity, and carbon sequestration potential of a red pine (Pinus resinosa Ait.) stand in the NE United States. Forest Ecology and Management 196: 173-186.
Aber, J. D. and A. H. Magill. 2004. Chronic Nigrogen Additions at the Harvard Forest: The First Fifteen Years of a Nitrogen Saturation Experiment. Forest Ecology and Management 196: 1-5.
Aber, J. D., A. Magill, K. J. Nadelhoffer, J. Melillo, P. Steudler, J. Hendricks, R. Bowden, W. Currie, W. McDowell, and G. Berntson. 2004. Exploring the process of nitrogen saturation. Pp. 259-279 In D. R. Foster and J. D. Aber (Eds.), Forests in Time: The Environmental Consequences of 1000 Years of Change in New England. Yale University Press, New Haven, CT.
Venterea, R. T., P. M. Groffman, L. V. Verchot, A. H. Magill, J. D. Aber, and P. A. Steudler. 2003. Nitrogen oxide gas emissions from temperate forest soils receiving long-term nitogen inputs. Global Change Biology 9: 346-357.
Currie, W. S., K. J. Nadelhoffer, and B. Colman. 2002. Long-term movement of 15N tracers into fine woody debris under chronically elevated N inputs. Plant and Soil 238: 313-323
Aber, J. D. 2002. Nitrogen saturation in temperate forest ecosystems: current theory, remaining questions and recent advances. Pp. 179-188 In Horst, W.J. et al (Eds.), Progress in Plant Nutrition: Plenary Lectures of the XIV International Plant Nutrition Colloquium. Kluwer Academic Publishers, Dordrecht
Dail, D. B., E. A. Davidson, and J. Chrover. 2001. Rapid abiotic transformation of nitrate in an acid forest soil. Biogeochemistry 54: 131-146
Bauer, G. A., G. M. Berntson, and F. A. Bazzaz. 2001. The effect of elevated CO2 and increased N availability on regenerating temperate forest communities: biochemical versus stomatal limitation of photosynthesis. New Phytologist 152: 249-266
Yano, Y., W. H. McDowell, and J. D. Aber. 2000. Biodegradable dissolved organic carbon in forest soil solution and effects of chronic nitrogen deposition. Soil Biology and Biochemistry 32: 1743-1751
Minocha, R., S. Long, A. H. Magill, J. Aber, and W. H. McDowell. 2000. Foliar free polyamine and inorganic ion content in relation to soil and soil solution chemistry in two fertilized stands at the Harvard Forest. Plant and Soil 222: 119-137
Magill, A. H., J. D. Aber, G. M. Berntson, W. H. McDowell, K. J. Nadelhoffer, J. M. Melillo, and P. A. Steudler. 2000. Long-term nitrogen additions and nitrogen saturation in two temperate forests. Ecosystems 3: 238-253
Magill, A. H. and J. D. Aber. 2000. Variation in soil net mineralization rates with dissolved organic carbon additions. Soil Biology and Biochemistry 32: 597-601
Magill, A. H. and J. D. Aber. 2000. Dissolved organic carbon and nitrogen relationships in forest litter as affected by nitrogen deposition. Soil Biology and Biochemistry 32: 603-613
Hendricks, J. J., J. D. Aber, K. J. Nadelhoffer, and R. D. Hallett. 2000. Nitrogen controls on fine root substrate quality in temperate forest ecosystems. Ecosystems 3: 57-69
Berntson, G. M. and J. D. Aber. 2000. Fast nitrate immobilization in N-saturated temperate forest soils. Soil Biology and Biochemistry 32: 151-156
Bell, S. 2000. Microbial nitrogen utilization under nitrogen-saturation conditions in temperate forests. Senior Thesis, University of Oregon
Rainey, S. M., K. J. Nadelhoffer, S. L. Silver, and M. R. Downs. 1999. Effects of chronic nitrogen additions on understory species abundance and nutrient content in a red pine plantation. Ecological Applications 9: 949-957
Nadelhoffer, K. J., B. A. Emmett, P. Gundersen, C. J. Koopmans, P. Schleppi, A. Tietema, and R. F. Wright. 1999. Nitrogen deposition and carbon sequestration. Nature 400: 630 (Reply to DS.Jenkinson, K. Goulding, D.S. Powlson, H. Seivering)
Nadelhoffer, K. J., B. A. Emmett, P. Gundersen, O. J. Kjønaas, C. J. Koopmans, P. Schleppi, A. Tietema, and R. F. Wright. 1999. Nitrogen deposition makes a minor contribution to carbon sequestration in temperate forests. Nature 398: 145-148
Nadelhoffer, K. J., M. R. Downs, B. Fry, A. Magill, and J. D. Aber. 1999. Controls on N retention and exports in a fertilized watershed. Environmental Monitoring & Assessment 55: 187-210
Nadelhoffer, K. J., M. R. Downs, and B. Fry. 1999. Sinks for 15N-enriched additions to an oak forest and a red pine plantation. Ecological Applications 9: 72-86
Currie, W. S., J. D. Aber, and C. T. Driscoll. 1999. Leaching of nutrient cations from the forests floor: effects of nitrogen saturation in two long-term manipulations. Canadian Journal of Forest Research 29: 609-620
McDowell, W. H., W. S. Currie, J. D. Aber, and Y. Yano. 1998. Effects of chronic nitrogen amendment on production of dissolved organic carbon and nitrogen in forest soils. Water, Air and Soil Pollution 105: 175-182
Magill, A. H. and J. D. Aber. 1998. Long-term effects of chronic nitrogen additions on foliar litter decay and humus formation in forest ecosystems. Plant and Soil 203: 301-311
Foster, D. R., J. Aber, J. Melillo, R. D. Bowden, and F. A. Bazzaz. 1998. Forest response to natural disturbance versus human-induced stresses. Arnoldia 58: 35-40
Fenn, M. E., M. Poth, J. D. Aber, J. S. Baron, B. T. Bormann, D. W. Johnson, A. D. Lemly, S. G. McNulty, D. F. Ryan, and R. Stottlemeyer. 1998. Nitrogen excess in North American ecosystems: a review of predisposing factors, geographic extent, ecosystem responses and management strategies. Ecological Applications 8: 706-733
Aber, J. D., W. H. McDowell, K. J. Nadelhoffer, A. H. Magill, G. Berntson, M. Kamekea, S. G. McNulty, W. Currie, L. Rustad, and I. Fernandez. 1998. Nitrogen saturation in temperate forest ecosystems: hypotheses revisited. BioScience 48: 921-934
Vitousek, P. M., J. D. Aber, S. E. Bayley, R. W. Howarth, G. E. Likens, P. A. Matson, D. W. Schindler, W. H. Schlessinger, and G. D. Tilman. 1997. Human alteration of the global nitrogen cycle: causes and consequences. Ecological Issues 1: 1-15
Magill, A. H., J. D. Aber, J. J. Hendricks, R. D. Bowden, J. M. Melillo, and P. A. Steudler. 1997. Biogeochemical response of forest ecosystems to simulated chronic nitrogen deposition. Ecological Applications 7: 402-415
Hendricks, J. J., K. J. Nadelhoffer, and J. D. Aber. 1997. A 15N tracer technique for assessing fine root production and turnover. Oecologia 112: 300-304
Foster, D. R., J. D. Aber, J. M. Melillo, R. Bowden, and F. Bazzaz. 1997. Forest response to disturbance and anthropogenic stress. Rethinking the 1938 Hurricane and the impact of physical disturbance vs chemical and climate stress on forest ecosystems. BioScience 47: 437-445
Magill, A. H., M. R. Downs, K. J. Nadelhoffer, R. A. Hallett, and J. D. Aber. 1996. Forest ecosystem response to four years of chronic nitrate and sulfate additions at Bear Brooks Watershed, Maine, USA. Forest Ecology and Management 84: 29-37
Currie, W. S., J. D. Aber, W. H. McDowell, R. D. Boone, and A. H. McGill. 1996. Vertical transport of dissolved organic C and N under long-term N amendments in pine and hardwood forests. Biochemistry 35: 471-505
Nadelhoffer, K. J., M. Downs, B. Fry, J. D. Aber, A. H. Magill, and J. M. Melillo. 1995. The fate of 15N-labelled nitrate additions to a northern hardwood forest in eastern Maine, USA. Oecologia 103: 292-301
Aber, J. D., A. Magill, S. G. McNulty, R. Boone, K. J. Nadelhoffer, M. Downs, and R. A. Hallett. 1995. Forest biogeochemistry and primary production altered by nitrogen saturation. Water, Air and Soil Pollution 85: 1665-1670
Micks, P. 1994. Soil respiration and nitrogen additions in two forest stands: short- and long-term responses. MS Thesis, University of New Hampshire
Hendricks, J. J. 1994. Assessing the effects of nitrogen availability on fine root turnover and tissue chemistry in forest ecosystems. Ph.D. Thesis, University of New Hampshire
Nadelhoffer, K. J., J. D. Aber, M. R. Downs, B. Fry, and J. M. Melillo. 1993. Biological sinks for nitrogen additions to a forested catchment. CEC Report of the Proceedings of the International Symposium on Experimental Manipulation of Biota and Biogeochemical Cycling in Ecosystems. Copenhagen
Crabtree, R. C. and F. A. Bazzaz. 1993. Seedling response of four birch species to simulated nitrogen deposition: Ammonium versus nitrate. Ecological Applications 3: 315-321
Aber, J. D., A. Magill, R. Boone, J. M. Melillo, P. A. Steudler, and R. Bowden. 1993. Plant and soil responses to three years of chronic nitrogen additions at the Harvard Forest, Petersham, MA. Ecological Applications 3: 156-166
Aber, J. D. 1993. Modification of nitrogen cycling at the regional scale: the subtle effects of atmospheric deposition. Pp. 163-174 In M. J. McDonnell and S. T. A. Pickett (Eds.), Humans as Components of Ecosystems. Springer-Verlag, NY
Aber, J. D. 1992. Nitrogen Cycling and Nitrogen Saturation in Temperate Forest Ecosystems. Trends in Ecology & Evolution 7: 220-223
Bowden, R. D., J. M. Melillo, P. A. Steudler, and J. D. Aber. 1991. Effects of nitrogen additions on annual nitrous oxide fluxes from temperate forest soils in the northeastern United States. Journal of Geophysical Research 96: 9321-9328
Aber, J. D., J. M. Melillo, K. J. Nadelhoffer, J. Pastor, and R. Boone. 1991. Factors controlling nitrogen cycling and nitrogen saturation in northern temperate forest ecosystems. Ecological Applications 1: 303-315
Bowden, R. D., P. A. Steudler, J. M. Melillo, and J. D. Aber. 1990. Annual nitrous oxide fluxes from temperate forest soils in the northeastern United States. Journal of Geophysical Research 95: 13997-14005
Steudler, P. A., R. D. Bowden, J. M. Melillo, and J. D. Aber. 1989. Influence of nitrogen fertilization on methane uptake in temperate forest soils. Nature 341: 314-316
Melillo, J. M. and P. A. Steudler. 1989. The effect of nitrogen fertilization on the COS and CS2 emissions from temperate forest soils. Journal of Atmospheric Chemistry 9: 411-417
Aber, J. D., K. J. Nadelhoffer, P. Steudler, and J. M. Melillo. 1989. Nitrogen saturation in northern forest ecosystems - Hypotheses and implications. BioScience 39: 378-386