This field trip is intended as an opportunity to observe a terrestrial Long Term Ecological Research (LTER) site. Since its establishment in 1907 the Harvard Forest has served as a base for research and education in forest biology. Through the years researchers at the Forest have focused on silviculture and forest management, soils and the development of forest site concepts, the biology of temperate and tropical trees, forest ecology and economics and ecosystem dynamics. Today, this research and educational legacy continues as the faculty, staff and students seek to understand historical and modern changes in the forests of central New England resulting from human and natural disturbance processes. This research activity is epitomized by the Harvard Forest Long Term Ecological Research (HF-LTER) program, which was established in 1988 through funding by the National Science Foundation (NSF).
The field trip will begin with a visit to the Fisher Museum and an introduction to the Forest and research activities. Discussions will highlight the effects of land use change and disturbance on biogeochemical cycling processes. We will then divide into smaller groups for rotating visits to specific research experiments. We will visit the Chronic Nitrogen Amendment Plots which were established to examine nitrogen saturation and thresholds for nitrate leaching in adjacent pine and hardwood stands. We will also visit the soil warming experiment, designed to study the effects of potential future climate warming on carbon and nitrogen cycling processes. Finally, the group will visit the eddy flux tower site, at which the effects of environmental variables on carbon dioxide exchange processes between the atmosphere and forest canopy are studied.
Physically, the Harvard Forest is comprised of approximately 3000 acres of land in Petersham, Massachusetts that include mixed hardwood and conifer forests, ponds, extensive spruce and maple swamps, and diverse plantations. Additional land holdings include the 25-acre Pisgah Forest in southwestern New Hampshire, a virgin forest of white pine and hemlock that was 300 years old when it blew down in the 1938 Hurricane; the 100-acre Matthews Plantation in Hamilton, Massachusetts, which is largely comprised of conifer plantations; and the 90-acre Tall Timbers Forest in Royalston, Massachusetts. In Petersham a complex of buildings that includes Shaler Hall, the Fisher Museum and Torrey Laboratories provide office and laboratory space, computer and greenhouse facilities, and a lecture room and lodging for seminars and conferences. An additional six houses and apartments provide housing for staff, visiting researchers and students. Extensive records of plant research, long-term data sets and historical information are maintained in the Harvard Forest archives.
Temperate forests are dynamic ecosystems that have been shaped through geologic and historical time by natural changes in the biotic and abiotic environment. Retrospective research and long-term studies document that temperate forests have been remarkably resilient to a wide range of natural environmental change and physical disturbance. Despite this apparent resiliency, novel human-imposed disturbances and stresses have impacted temperate regions with increasing frequency over past centuries and may surpass the ability of forests to recover and to control important ecosystem processes. Massive land-use change has altered the extent and structure of forests as well as hydrological, meteorological and pedological processes. Changes in the global earth-atmosphere system have resulted in significant increases in the deposition of air pollution and may rapidly alter energy budgets in north temperate regions. Introduced pathogens and exotic organisms continue to produce selective changes in the abundance of major forest species. An important question facing ecologists, natural resource managers, and policy makers is: Are temperate forests as resilient (and/or resistant) to these novel physical, chemical and climatic stresses as they are to natural disturbance and environmental change?
For more information on the Harvard Forest LTER, see http://www.lternet.edu/hfr. For more information about this field trip, please contact Doug Burns, +1-518-285-5662, daburns@usgs.gov, or Ellyn Terry, +1-202-777-7335, eterry@agu.org.