Smithsonian Scientist Uses Innovative Method to Predict How Forests Will Change Over Time

Many factors affect the future of forests, making it complicated to develop predictions about where they will disappear and where they will flourish, what types of trees they will include and how much carbon they will store in the years to come. In a paper published in this month's issue of BioScience, a scientist at the Smithsonian Conservation Biology Institute explores the potential of a creative technique to look toward the future of forests.

I tend to focus on socioecological systems—systems people muck around in—where prediction is largely impossible, said Jonathan Thompson, lead author of the paper and SCBI research ecologist. Scenario studies are different in that they don't try to predict anything; instead they examine a range of plausible futures.

In a scenario study, scientists examine possible futures, rather than historical data, to inform simulation models. It is similar to the methods that the Defense Department used in its war games and is now a growing trend in business and socioecological research. The paper published this month explores the scenario opportunities offered by the Long Term Ecological Research network, which has been measuring plant growth, soil composition, nutrient cycling and many other factors for the past 30 years and now includes 26 different sites. Those sites include a wide range of ecosystem types spanning from Alaska to Antarctica and from the Caribbean to French Polynesia. Scenario studies offer an opportunity for LTER scientists to leverage their long-term datasets for comprehensive examinations of future actions society could take, according to Thompson.

Last fall Thompson and collaborators used scenario studies to examine how land use and climate change might affect growing trees and their ability to store carbon in Massachusetts. They determined that under current trends, development will reduce that storage by 18 percent over the next half century. This is one of five scenario studies examined in the BioScience paper.

The rebounding forests of New England provide a tremendous public benefit by storing carbon that would otherwise contribute to climate change, Thompson said. In Massachusetts, forests capture approximately 2.3 million metric tons of carbon each year, which is equal to the carbon dioxide emitted annually from the energy used by 1 million American homes.

Ongoing scenario science work focuses on forests within Massachusetts, and a new project will apply this method to five of the most heavily forested regions in the United States, adding New Hampshire and Vermont. In the long term, the project will not only compare across scenarios and regions, but also look at how regions could affect one another. The range of possible scenarios could help land managers and conservationists manage the land accordingly and policymakers identify actions that increase ecological resilience to land use and climate change.

In addition to Thompson, the paper's authors are Arnim Wiek from the School of Sustainability at Arizona State University; Frederick Swanson and Thomas Spies at the U.S. Forest Service's Pacific Northwest Research Station; Stephen Carpenter from the Center for Limnology at the University of Wisconsin-Madison; Nancy Fresco from the School of Natural Resources and Agricultural Science at the University of Alaska, Fairbanks; Teresa Hollingsworth from the Boreal Ecology Cooperative Research Unit at the University of Alaska, Fairbanks; and David Foster at Harvard University's Harvard Forest.

The Smithsonian Conservation Biology Institute plays a key role in the Smithsonian's global efforts to understand and conserve species and train future generations of conservationists. Headquartered at a Smithsonian facility in Front Royal, Va., SCBI facilitates and promotes research programs based at Front Royal, the National Zoo in Washington, D.C., and at field research stations and training sites worldwide.