Paleoecology
By investigating microscopic plant and animal fossils that accumulate in sedimentary environments such as ponds, wetlands, and organic soils it is possible to reconstruct past changes in vegetation, plant and animal communities, environment, and disturbance processes. A variety of paleoecological approaches including pollen, diatom, charcoal, and chironomid analyses are used at the Harvard Forest in conjunction with modern and historical studies to investigate fundamental ecological questions and to provide a background for conservation and land management. Harvard Forest researchers have concentrated especially on the landscape changes that occur before and as a consequence of European settlement and on stand-level forest dynamics.
Regional studies
Cape Cod, Islands & Long Island
New England-wide
Forest dynamics and small hollows
By analyzing pollen, charcoal, and other fossil materials contained in the humus soils of forests or in the sediments of vernal pools, small forest hollows, and wetlands it is often possible to develop lengthy records of very local forest dynamics. Researchers at the Harvard Forest have utilized this approach successfully in a number of different forest types in central New England. These studies reveal the nature of the pre-European forests and environments, information on natural forest disturbance, and considerable insights into the extent of forest change that has transpired due to historical land-use practices. In all cases this paleoecological information adds considerable additional insight to companion studies of the current forest condition and historical documents.
Post-glacial vegetation changes
Harvard Forest researchers also analyze the sediments of New England lakes to reconstruct the environmental and ecological changes that have occurred since the retreat of the continental ice sheet at the end of the last glacial period. This research reveals changes in the regional vegetation in response to millennial- to century-scale climatic variability, as well as to disturbance. In particular, these studies focus on the dramatic regional decline of hemlock ~5400 years ago, an event that has been attributed to pathogenic insect activity and the onset of dry climatic conditions.
Peatland dynamics
Peatlands are important ecosystems in New England and their sediments contain considerable information regarding past changes in the climate, hydrology, and vegetation of the region. A number of studies at the Harvard Forest have investigated the vegetation and especially the developmental history of forested wetlands in the region. These studies utilize a range of paleoecological approaches including stratigraphic analyses of pollen, peat types, and charcoal, radiocarbon dating, and comparative analyses of neighboring lakes and hollows. In addition to providing insights into environmental and vegetation change in the region, these studies have revealed much new information about the basic development of the wetlands themselves.
Selected Publications
McLachlan, J., D. Foster, S. Clayden, and S. Barry. 2004. Long-term forest and landscape dynamics. Pp. 125-141 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.
Fuller, J., D. R. Foster, G. Motzkin, J. McLachlan, and S. Barry. 2004. Broad-scale forest response to land-use and climate change. Pp. 101-124 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.
Parshall, T., D. Foster, E. Faison, D. MacDonald, and B. C. S. Hansen. 2003. Long-term history of vegetation and fire in pitch pine-oak forests on Cape Cod, Massachusetts. Ecology 84: 736-738.
Anderson, R. L., D. R. Foster, and G. Motzkin. 2003. Integrating lateral expansion into models of peatland development in temperate New England. Journal of Ecology 91: 68-76.
Foster, D., S. Clayden, D. A. Orwig, B. Hall, and S. Barry. 2002. Oak, chestnut and fire: climatic and cultural controls of long-term forest dynamics in New England. Journal of Biogeography 29: 1359-1379.
Francis, D. R. and D. R. Foster. 2001. Response of small New England ponds to historic land use. The Holocene 11: 301-312.
McLachlan, J., D. R. Foster, and F. Menalled. 2000. Anthropogenic ties to late-successional structure and composition in four New England hemlock stands. Ecology 81: 717-733.
Foster, D. R. 2000. Linking the deep and recent past to the modern New England Landscape. Rhodora 102: 278-279.
Fuller, J. L., D. R. Foster, J. S. McLachlan, and N. Drake. 1998. Impact of human activity on regional forest composition and dynamics in central New England. Ecosystems 1: 76-95.
Fuller, J. L. 1998. Ecological impact of the mid-Holocene hemlock decline in southern Ontario, Canada. Ecology 79: 2337-2351.
Fuller, J. L. 1997. Holocene forest dynamics in southern Ontario, Canada: fine-resolution pollen data. Canadian Journal of Botany 75: 1714-1727.
Foster, D. R. and T. M. Zebryk. 1993. Long-term vegetation dynamics and disturbance history of a Tsuga-dominated forest in New England. Ecology 74: 982-998.
Foster, D. R., T. Zebryk, P. Schoonmaker, and A. Lezberg. 1992. Post-settlement history of human land-use and vegetation dynamics of a hemlock woodlot in central New England. Journal of Ecology 80: 773-786.