Looking Down the Line

CAFNR research team publishes long-term projections of massive forest region with help of climate science center

To Curt Griffin, there was only one person to call. When the Northeast Climate Science Center was forming approximately five years ago, the consortium of universities and institutions needed a member that had a specialty in landscape modeling.

Griffin, who works as a professor and department head at the University of Massachusetts Amherst’s department of environmental conservation, graduated with both master’s and doctoral degrees in wildlife ecology from the University of Missouri. Given his background, he was well aware of the research that Frank Thompson — a former Ph.D. classmate of his in the mid ’80s — and his team members were doing in regards to the LANDIS (LANdscape DIsturbance and Succession) simulation model.

Wen Wang and Frank ThompsonWen Wang and Frank Thompson

A call to Thompson was made. Soon thereafter, MU became one of seven original members of the NECSC in the spring of 2011, in spite of the fact that the state is generally not considered to be part of the northeastern region of the United States. “The northeast is loosely defined,” said Thompson, who works as both a cooperative professor in the department of fisheries and wildlife in the School of Natural Resources as well as a senior scientist with the U.S.D.A. Forest Service. He also serves as one of the principal investigators with the NECSC.

Thompson and a group of other MU researchers recently published a paper in the December edition of the Ecological Society of America’s journal, Ecosphere, which looked at long-term projections based on the effects of succession, disturbance and climate change in 23 prominent tree species in a large swath of land known as the Central Hardwood Forest Region. The area is made up of 14 ecological sections that cover approximately 309 million acres in portions of 15 states, stretching from the eastern border of Pennsylvania to southeastern Oklahoma and from upstate New York to northern Alabama.

The research in the paper represents a collaboration with the U.S. Forest Service and the NECSC. The projections were reached by using three widely-used global circulation models, all of which predict climate warming, from a mild change of two degrees to a more severe increase of seven degrees by the end of the century.

Those projections of climate change are then used in LANDIS PRO, the latest version of the landscape stimulation model, which was first developed in 2011 by then-MU doctoral student Wen Wang, who is the lead author on the paper, and Hong He, professor of forestry in the School of Natural Resources, who is also an author on the paper. As a result, Wen, He, Thompson and company can look at what is believed to be a more accurate projection of trees from now until the year 2300 at a more finite level than ever before.

A time for more pines?

The entire portion of Missouri that is included in the Central Hardwood Forest Region sits in the Ozark Highlands section, which is traditionally dominated by various types of oaks (such as white, black, northern red) and hickories and lesser amounts of eastern red cedar, short leaf pine and sugar maple. Based on the projections, some oaks and sugar maples, which are near the southern ridge of the range, could possibly be replaced by those that currently thrive in warmer climates to the south, such as the shortleaf pine and loblolly pine.

Thompson said that even if those two particular species are favored by future climates, it will take hundreds of years to see large changes in their abundance because trees require their seeds to be windblown, carried by animals or planted by humans. “One of the options that leaves people to think about is should we facilitate change by considering planting species that might be more adapted to future climates? Now that we have an idea of how climate might change these forests, then we can start asking the question: ‘Should we be managing them differently for the future than we are now?’”

A large amount of the southern portion of Missouri makes up part of the western front of the Central Hardwood Forest Region. Graphic courtesy of Wen Wang. A large amount of the southern portion of Missouri makes up part of the western front of the Central Hardwood Forest Region. Graphic courtesy of Wen Wang.

Previous approaches to modeling forest change in response to climate change worked at coarser resolutions such as 10 to 15 kilometer pixels or blocks of land. That number has gone down to 270 meters on the LANDIS PRO. “We can now also simulate very fine-scale processes,” said Wen, who has worked as a postdoctoral fellow in the department of forestry since 2012. Those fine-scale processes include tree reproduction and growth, mortality, and competition — and how they vary with topography, temperature and precipitation.

“I think this project is pretty unique in the fact that we’re simulating at a pretty fine scale all of those site-level processes like tree growth and competition and regeneration,” Thompson added. “People have done one or the other, but have not brought those together at this fine of a scale across this big of a landscape.”

To create the starting conditions of the projections, the team relied on remote sensing data from satellites as well as forest inventory data from the U.S. Forest Service. “By matching that inventory data up with aerial photography or satellite imagery, we can fill in what trees should be in all of those pixels across the landscape,” Thompson said.

Joining forces

Funded by a grant by the U.S. Department of the Interior, the NECSC makes up one of eight federal climate science centers created (in the words of the center’s website) “to provide scientific information, tools, and techniques that managers and other parties interested in land, water, wildlife and cultural resources can use to anticipate, monitor, and adapt to climate change.” The other primary funder of the work is the U.S.D.A. Forest Service.

Although the NECSC is based on the UMass campus, the geographical layout of the consortium of schools and institutions is as vast as the region itself. In addition to MU, the other members are Columbia University in New York City, the Marine Biological Laboratory in Massachusetts, the College of Menominee Nation in Wisconsin, the University of Wisconsin and the University of Minnesota.

The study looked at the 23 different trees that are native to the Central Hardwood Forest Region. Photo courtesy of Andy Castillo.The study looked at the 23 different trees native to the Central Hardwood Forest Region. Photo courtesy of Andy Castillo.

Thompson and his fellow principal investigators meet annually in addition to monthly conference call. In addition, the graduate students and postdoctoral fellows, whose work is funded by the NECSC, have an annual retreat. In 2014, MU hosted the event, which started out at the Reis Biological Station in Steelville and then progressed on a tour of the northern portion of the Missouri Ozarks where participants met with local land owners to learn how climate change was affecting them.

Thompson and company have been working on LANDIS simulation models for more than 20 years now. They had already started to shift their focus to climate change before getting involved in the NECSC.

“This has been a long-term evolution,” Thompson said. “Recent advancements in our models is letting us now look at climate change, which potentially could have have a huge effect on forests and wildlife in North America.”

The information has already started to be included in informational books and other materials written and referenced by both state and federal management agencies and private conservation organizations.

“The whole idea here is for this information to get used to assess the vulnerability of the forest to climate change and unable us to make them better adapted for the future,” Thompson said.