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David Foster advocates passive role in forest management

To understand how forests adapt over time, AAAS member David Foster conducts research at the 3500 acre Harvard Forest, located 70 miles west of Boston in Petersham, Massachusetts. (Photo:

Every NFL team in America could simultaneously play in David Foster's laboratory, with plenty of room to spare for fans and parking. The 3500 acre Harvard Forest, located 70 miles west of Boston in Petersham, Massachusetts, is home to experiments that can take decades to run. In the wake of superstorms like Hurricane Sandy, his experiments are vital for the management of forests in New England.

"To do nothing. That is a valid management option," Foster said, referring not only to storm cleanup but also to the control of invasive species such as the Hemlock Wooly Adelgid and the Asian Longhorned Beetle. He acknowledges that although a passive management style is not the easiest for people to accept, it may be the best option for maintaining forest ecology.

The Harvard Forest was established in 1907, but has been funded since 1988 by the National Science Foundation as one of 26 Long-Term Ecological Research Sites scattered across North America, Antarctica, and the Caribbean. The Harvard Forest is unique among the sites for being a department of Harvard University instead of a simple field station. The forest employs over 40 permanent staff for administration and to conduct experiments ranging from simple observations to full-scale simulations.

Foster and his fellow researchers will soon publish the 20 year results of a simulated hurricane in the journal Ecology. In 1990, they pulled down almost 300 trees in a two-acre section of Harvard Forest, mimicking the devastation wrought by the high-speed winds of a major storm. After the felling, they conducted the most important part of the experiment - they didn't touch anything.

For over 20 years the blasted patch has been left alone and closely observed. Samples were taken and species were counted, but the trees remained where they fell as the ecosystem slowly recovered. The most encouraging finding was that the damaged area resisted encroachment from invasive species, and recovered more quickly than expected. Tree seedlings and sprouts from fallen trees were found to have the most impact on recovery, and there was little change to most species populations.

The findings are encouraging in light of the increase in major weather events across the country. Earlier in 2012, Hurricane Isaac raced across the Gulf Coast. In late October Hurricane Sandy caused major flooding along the East coast. Although the Harvard Forest was not damaged in the storm, Foster notes that his work has become increasingly important for dealing with the aftermath of severe weather conditions.

"It's an exciting time, because there is so much difference you can make," Foster said.

Of course, storms such as Sandy are not the only threats to New England Forests. About 5,000 years ago eastern hemlock trees were nearly wiped out from unknown causes. They gradually recovered in the Appalachian region, but are being threatened again by pests such as the Hemlock Wooly Adelgid, an aphid-like insect from Asia that was probably introduced to the U.S. from imported ornamental plants. Since 1951 the invasive pest has spread from Georgia to Maine, and is one of the primary stressors of the coniferous hemlock tree.

The history of hemlock populations is written in the pollen record, and researchers like Foster can chart the progress of recovery after sharp declines by studying pollen fossils.

"You have the ability to look back in time to when this happened before, and how it recovered," said Foster. The pollen record and Harvard Forest research can also reveal how the loss of hemlock affects other plant, animal, and insect species that depend on the trees for food and shelter.

Foster applies the same theory of interconnectedness to his research and conservation methods. He is one of the authors on the Wildlands and Woodlands project, which works to encourage landowners in New England to protect their undeveloped lands in perpetuity through easements. A report from the U.S. Forest Service claimed that 80 percent of New England forests were privately owned, offering great potential for preservation. Through computer models and data analysis, Foster can determine the effects of future scenarios on the health of the forests.

"Wildlands and Woodlands is an unusual effort because it comes out of academia," he said. "It's a grassroots organization, which makes it very American."

Finally, Foster applies a holistic approach to his research as well. Through organizations like AAAS, scientists from different disciplines can combine their research to form more complete pictures of reality than would be possible alone. For example, Foster says that social scientists could help him understand landowner behavior, and what might motivate them to conserve their property.

"The single most important thing we can do is promote Wildlands and Woodlands efforts," he said.

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To understand how forests adapt over time, AAAS member David Foster conducts research at the 3500 acre Harvard Forest, located 70 miles west of Boston in Petersham, Massachusetts. (Photo:
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