Progress 10/01/09 to 09/30/12
Outputs
OUTPUTS: The health of forest ecosystems in the northeastern United States is threatened by many forces including climate change, exotic pests and pathogens, native herbivores, acid deposition and other air pollutants and non-sustainable harvest practices. The development of policies and management systems to maintain and optimize forest values in the face of these human-accelerated environmental changes depends upon quantitative information on forest change. The goal of this research was to provide an improved understanding of the response of northeastern forest ecosystems to human-accelerated environmental change. The specific objective was to quantify the growth, recruitment and mortality of trees growing in permanent plots at three intensive research sites in the Northeast: Hubbard Brook Experimental Forest, NH; Arnot Forest, NY; and Delaware Water Gap, PA. The principal outputs from this research included a series of publications in the peer-reviewed scientific literature detailing the study results and implication; extensive datasets from the research posted for public access on the website of the Hubbard Brook Ecosystem Study (http://www.hubbardbrook.org/); presentation of results at regional and national scientific meetings; and extension of observation to public audiences, through the NYS Extension system, especially in the area of invasive pests and pathogens. PARTICIPANTS: INDIVIDUALS working on project: Elle Erpenbeck - Undergrad; Alexis Heinz - Research technician, Cornell University; Catherine Fahey - Undergrad; Natalie van Doorn - Graduate student, currently PhD candidate, University of California, Berkeley; Anne Eschtruth - Graduate student, currently post-doc, University of California, Berkeley; Natalie Cleavitt, Research associate, Cornell University; Rebecca Terry - Undergrad, Cornell University; Tianjun Hou - Undergrad, Cornell University; Anna Plattner - Undergrad, Cornell University TRAINING and PROFESSIONAL DEVELOPMENT Undergraduate students participated in formal internship programs at Hubbard Brook and Arnot Forest. Some of these students also developed Senior Honors thesis research at Cornell based on their work (Fahey, Hou, Plattner, Terry). The research technician (Heinz) developed new skills in database management and statistical analysis. TARGET AUDIENCES: 1. Principal audience is scientific researchers in the discipline of forest ecology and management. 2. Secondary audience is land management professionals at state and local level working on strategies to respond to threats from invasive forest insect pests. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
During the three-year duration of this project we completed surveys of forest vegetation and invasive organisms on a suite of permanent plots at three northeastern forest sites (Hubbard Brook Experimental Forest (HBEF), Arnot Teaching and Research Forest (Arnot), Delaware Water Gap National Recreation Area (DWG). Research at these three sites has advanced our understanding of forest health responses to a variety of stressors, including acid deposition, climate change and spread of invasive species. We highlight the following key observations: (1) At the HBEF we demonstrated that replacement of calcium lost from watershed-ecosystems during the 20th century resulted in dramatic recovery of forest health in sugar maple dominated forest. These results indicate conclusively that acid deposition has significantly reduced the productivity of northeastern forests; (2) The invasion of exotic earthworms has reduced soil C storage by about one-third in forests on the Allegheny Plateau; however, earthworm distributions do not appear to be continuing to spread at least on decadal time scales; (3) Large herbivores (deer and moose) interact in complex ways with forest vegetation and soil invertebrates to influence the trajectory of forest change; (4) Invasive insect pests and pathogens play a key role in forest change throughout the Northeast. Beech bark disease continues to influence the composition and biomass of forest at HBEF and Arnot. Hemlock wooly adelgid (HWA) has caused high mortality in permanent plots at DWG, influencing nature and invasive plants, deer and stream habitat, and future forest composition. Both HWA and emerald ash borer are poised to invade forests at HBEF and Arnot. The resources provided by this project, especially in terms of supporting field measurement, have been essential to the successful completion of this permanent plot research.
Publications
- Cleavitt, N.L., T.J. Fahey and J.J. Battles. 2011. Regeneration ecology of sugar maple (Acer saccharum Marsh.): seedling survival in relation to nutrition, site factors and damage by insects and pathogens. Canadian Journal of Forest Research, 41:235-244.
- Fahey, T.J., R.E. Sherman, and D.A. Weinstein. 2012. Demography, biomass and productivity of a northern hardwood forest on the Allegheny Plateau. Journal of Torrey Botanical Society, in press.
- Groffman PM, LE Rustad, PH Templer, JL Campbell, LM Christenson, NK Lany, AM Socci, MA Vadeboncoeur, PG Schaberg, GF Wilson, CT Driscoll, TJ Fahey, MC Fisk, CL Goodale, MB Green, SP Hamburg, CE Johnson, MJ Mitchell, JL Morse, LH Pardo and NL Rodenhouse. 2012. Long-Term Integrated Studies Show Complex and Surprising Effects of Climate Change in the Northern Hardwood Forest. Bioscience 62: 1056-1066. DOI: 10.1525/bio.2012.62.12.7
- Stoscheck, L.M., R.E. Sherman, E.R. Suarez and T.J. Fahey. 2012. Exotic earthworm distributions did not expand over a decade in a hardwood forest in New York state. Appl. Soil Ecol. 62:124-30 http://dx.doi.org/10.1016/j.apsoil.2012.07.002
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: Our work on long-term forest dynamics has been focused at three intensive sites: Hubbard Brook, NH (HBEF); Arnot Forest; and Delaware Water Gap (DWG). In the last year we completed analysis of data sets from the fourth re-survey of "Birdline" plots at HBEF and the eight resurvey of W6 at HBEF. The data from HBEF are posted on the website of the Hubbard Brook Ecosystem Study (http://www.hubbardbrook.org/) and are frequently used by colleagues at a variety of institutions around the world in support of complementary research. The results have been reported at both HBEF project meetings and national scientific meetings. In addition, the project contributed to outreach activities in the HBES through interactions with the USDA Forest Service Environmental Literacy Program. Secondary school teacher training and curriculum development projects were conducted in the past year. In 2010 we also added a new research component focusing on invasive pests and pathogens. At HBEF we initiated an early-detection protocol for hemlock woolly adelgid (HWA) and emerald ash borer (EAB). New research on survey and eradication methods for both HWA, EAB has been initiated at Arnot Forest. PARTICIPANTS: Ang Li, graduate student; Ruth Sherman, research associate; Mark Whitmore, extension associate TARGET AUDIENCES: Forestry professionals, secondary school teachers, envirionmental policy makers PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Continuing research at the three sites illustrates variation in regional trends of forest health in response to a variety of stressors. Long-term trends in demography, biomass and productivity at Arnot Forest indicate that it departs from regional trends of forest decline associated with acid deposition and climatic events. However, the impending spread of HWA and EAB is threatening to reverse this situation. Moreover, the spread of exotic earthworms across the landscape has affected key soil properties and possibly forest health. At HBEF the combination of soil calcium depletion by acid deposition, climatic events and invasive pests has profoundly affected forest health and biomass accumulation. Interactions with populations of large herbivores (deer, moose) are influencing forest dynamics at all three sites. Hence, a complex suite of processes and mechanisms is operating to cause radical, rapid changes in northeastern forest dynamics, processes that could override or reinforce changes expected from global warming. Continued monitoring of the forests at these sites will provide valuable information for understanding and predicting the future of America's forests.
Publications
- Raciti, S.M., T.J. Fahey, C.T. Driscoll, F.J. Carranti, D.R. Foster, P.S. Gwyther, B.R. Hall, S.P. Hamburg, J.C. Jenkins, J.P. Jenkins, C. Neill, S.V. Ollinger, B.W. Peery, E. Quigley, R.E. Sherman, R.Q. Thomas, M.A. Vadeboncoeur, D.A. Weinstein, G. Wilson, P.B. Woodbury. 2011. Local-scale Carbon Budgets and Mitigation Opportunities for the Northeastern United States. BioScience 62(1): 23 - 38. doi:10.1525/bio.2012.62.1.7
- Van Doorn, N.S., J.J. Battles, T.J. Fahey, T.G. Siccama and P.A. Schwarz. 2011. Links between biomass and tree demography in a northern hardwood forest: A decade of stability and change in Hubbard Brook Valley, New Hampshire. Can. J. For. Res. 41(7):1369-1379.
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: Our work on long-term forest dynamics has been focused at three intensive sites: Hubbard Brook, NH (HBEF); Arnot Forest; and Delaware Water Gap (DWG). In the last year we completed the census of three large (10 ha) demography mapped plots at HBEF and analysis of 75 yrs of forest change at Arnot. The data from HBEF are posted on the website of the Hubbard Brook Ecosystem Study (http://www.hubbardbrook.org/) and are frequently used by colleagues at a variety of institutions around the world in support of complementary research. The results have been reported at both HBEF project meetings and national scientific meetings. In addition, the project contributed to outreach activities in the HBES through interactions with the USDA Forest Service Environmental Literacy Program. Secondary school teacher training and curriculum development projects were conducted in the past year. In the Arnot Forest project, two undergraduate students participated in the field research and one is conducting a Senior Honors Thesis on this project. At DWG a post-doctoral associate and PhD student participated in sampling and data analysis. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Long-term trends in demography, biomass and productivity at Arnot Forest indicate that it departs from regional trends of forest decline associated with acid deposition and climatic events. However, the impending spread of hemlock wooly adelgid and emerald ash borer is threatening to reverse this situation. Moreover, the spread of exotic earthworms across the landscape has affected key soil properties and possibly forest health. The implications for ecosystem carbon sequestration have been evaluated. At HBEF the combination of soil calcium depletion by acid deposition, climatic events and invasive pests has profoundly affected forest health and biomass accumulation. Interactions with populations of large herbivores (deer, moose) are influencing forest dynamics at all three sites. Hence, a complex suite of processes and mechanisms is operating to cause radical, rapid changes in northeastern forest dynamics, processes that could override or reinforce changes expected from global warming. Continued monitoring of the forests at these sites will provide valuable information for understanding and predicting the future of America's forests.
Publications
- Hopfensperger, K.N., G.M. Leighton, and T.J. Fahey. 2011. Influence of invasive earthworms on above and belowground vegetation in a northern hardwood forest. Amer. Midl. Nat., in press.
- Fahey, T.J., J.B. Yavitt, R.E. Sherman, P.M. Groffman, M.C. Fisk, and J.C. Maerz. 2011. Transport of carbon and nitrogen between litter and soil organic matter in a northern hardwood forest. Ecosystems, in press.
- Huang, C.Y., Hendrix, P.F., Fahey, T.J., Bohlen, P.J. and Groffman, P.M. 2010. A simulation model of earthworm the impacts of invasive earthworm on soil carbon dynamics. Ecol. Model. doi:10.1016/j.ecolmodel.2010.06.023
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