Land-Use Legacies
Harvard Forest in Petersham, MA. Photo © 2004 Faculty of Arts and Sciences of Harvard University.
DB: This is Earth and Sky. Scientists studied a New England forest for more than a decade – to trace the history of that forest back 1,000 years.
JB: David Foster of Harvard University is the Director of the three-thousand-acre Harvard Forest in Petersham, Massachusetts. He and other scientists learned to identify human impacts from the past in the Harvard Forest – and track them, like footprints, over time.
DB: They used historical records – and the structure of present-day soil layers – to see the past in modern forests. For example, when European settlers came to New England over 400 years ago, they cleared the forests and farmed the land. Later, most agriculture shifted westward, and the forests regrew. Now these researchers see the legacy of the settlers’ past land use – in the distribution of plant and animal species, in soil nutrient levels, in the presence of invasive species, and more.
JB: Meanwhile, a study in Madagascar showed that logging practices from 50 to 150 years ago let invasive plants take hold. These researchers say the former logging sites might be permanently altered. David Foster wants to see immense tracts of land protected – allowed to return to their natural patterns and processes. He reminded us that what we do to the land today will create its own legacy for the future.
DB: Thanks to the U.S. Forest Service and to the National Fish and Wildlife Foundation. We’re Block and Byrd for Earth and Sky.
Links:
Ranomafana National Park (the park in Madagascar where the research described in the script above was done – Stony Brook University).
Web site for Institute for the Conservation of Tropical Environments (Stony Brook University)
The Case of Missing Carbon (National Geographic article on land-use legacies at)
Other Sources:
Foster, D. and J. Aber (eds.) 2004. Forests in Time: The environmental consequences of 1,000 years of change in New England. Yale University Press. Foster, D. et al. (2003). The importance of land-use legacies to ecology and conservation. Bioscience, vol. 53, no. 1, 77-88.
Brown, K.A. and J. Gurevitch (2004). Long-term impacts of logging on forest diversity in Madagascar, Proceeding of the National Academy of Sciences, vol. 101, no. 16, 6045-6049
Authors Notes: Foster stressed that you can’t begin to understand the ecology of a modern landscape, without first grasping the history of the site. This is true not only in New England, says Foster, home of the Harvard Forest, but in forests, ponds, lakes and streams, anywhere – from Brazil, to Great Britain, to the Yucatan Peninsula.
Kerry Brown and Jessica Gurevitch are researchers at Stony Brook University. They studied the way that logging practices from 50 to 150 years ago have altered forests in Madagascar?a so-called “hotspot” of biodiversity. Brown says that the species composition and diversity in logged sites are low, and that the sites might be permanently altered.
Brown and Gurevitch also studied a site damaged by a cyclone?a more “natural” occurrence than clear-cut or selective logging. In that area, the invasive plant never established and the forest is returning to its native state. The invasive plant that colonized the logged sites was once used to make jelly. Its species name is Psidium cattleianum.
The following people were interviewed for today’s program. Our thanks to:
David R. Foster
Director
Harvard Forest
Harvard University
Petersham, MA
Kerry Brown
Graduate Student
Department of Ecology and Evolution
Stony Brook University
Stony Brook, NY
Jessica Gurevitch
Professor
Department of Ecology and Evolution
Stony Brook University
Stony Brook, NY
