Research spans the South: Cross-site studies of the Experimental Forest Network

winter forest scene
The SRS Experimental Forest Network spans every type of ecoregion in the South, and most sites are located on national forests. USDA Forest Service photo.

A small team of USDA Forest Service employees are making huge contributions to the SRS Experimental Forest Network. Chuck Burdine and Bryan Mudder are key members of this team. For the past two years, they have been on temporary assignments as western and eastern regional coordinators, respectively.

“When I took on the regional coordinator role, I began to train for the Forest Inventory and Analysis certification,” says Burdine. “I fell in love with the woods again.”

Burdine, Mudder, and members of the field crews – Jacob Floyd, Virginia McDaniel, and Edd Watson – are working towards becoming certified FIA technicians. It is a lengthy process that Eric Winters has already completed. “It was a huge accomplishment that would not would not have been possible without the help of Marcus Wood,” says Mudder.

The FIA component is critical to the Experimental Forest Network, as originally conceptualized. The plan was for SRS technicians to become FIA certified and contribute to the Network part-time. But installing permanent FIA plots is a lengthy process, as is sampling. And the pandemic disrupted training schedules.

However, FIA plots on Coweeta Hydrologic Laboratory (Coweeta) and the Bent Creek, Blue Valley, and Palustris Experimental Forests (EFs) have been installed. The Calhoun and Harrison EFs will likely be next.

Burdine and Mudder also facilitate research beyond the borders of each experimental forest. Some of these projects are complete or are well underway:

  • Michael Ulyshen is surveying pollinators on each of the southern experimental forests. “This survey is a great example of how the Experimental Forest Network leads to success,” says Mudder, who found technicians to help install and monitor the traps.
  • Devendra Amatya led a study that will help engineers assess culvert capacity on forest roads during extreme precipitation events. The study was published in the Journal of Hydrologic Engineering. It took place at Coweeta and the Alum Creek and Santee EFs.
  • JT Vogt and collaborator Rebecca Trout-Fryxell of the University of Tennessee are sampling ticks on three sites in western North Carolina: Coweeta, Blue Valley EF, and Bent Creek EF. The study is related to previous tick surveys conducted with FIA and other partners.
  • Dana Nelson, Don Bragg, Mac Callaham, Burdine, and partners from the National Forest System, universities, and the Shortleaf Pine Initiative are conducting a common garden study for shortleaf pine. The study will explore shortleaf pine genetic diversity across the Network.

Several other studies are in progress. Most of them span the entire Network and involve close collaboration with national forests and other research partners. In 2021, five studies were funded:

longleaf pine vista
Each experimental forest has different levels of staffing, data, and active research. Many sites have decades of data, with new datasets being digitized and added. USDA Forest Service photo by Erich Vallery.
  • A representativeness plan to statistically direct growth of the Network, led by Bill Hargrove and Jitu Kumar of Oak Ridge National Laboratory.
  • An assessment of longleaf pine, shortleaf pine, and other yellow pines across the Southeast, focused on factors affecting where pines grow, led by Tara Keyser, Mac Callaham, and Leah Rathbun of North Carolina State University.
  • A synthesis of remote sensing products and assessment of key ecosystem functions across the Network from 2000 to 2020, led by Ge Sun and Jingfeng Xiao of the University of New Hampshire.
  • Characterization of soil’s physical properties, nutrients, and carbon-storing abilities, led by Carl Trettin.
  • A survey of frogs, toads, and other amphibians on experimental forests and national forests, led by Dan Saenz and Chris Schalk of Stephen F. Austin State University.

The work is highly collaborative. For example, national forest managers have already contributed to the amphibian monitoring project, providing maps and GPS coordinates of ponds on experimental forests and national forests. “We wouldn’t have time to search the woods for these ponds – and we don’t have to, because this information is already known,” says Burdine.

pollinator research study
Wildlife biologist Phillip Jordan installs traps for the cross-site pollinator study. USDA Forest Service photo.

Almost all the 20 sites in the Network are located on national forests.

“There’s research potential at the district that we know about because we interact with them,” says Burdine.

Burdine and Mudder wear many hats. Their work with the Experimental Forest Network is in addition to their other duties. “It’s a balancing act,” says Mudder. Mudder and Burdine do fieldwork, laboratory analysis, administrative work, and other duties unrelated to the Network. For example, Burdine does purchasing and payments for the Harrison EF and helps with facilities. If the drier in the guest quarters stops working, he may check the power or call an electrician.

Despite the hurdles, the Experimental Forest Network is renewing the research value of sites that were established almost a hundred years ago.

Johnny Boggs and Stephanie Laseter are Network co-leads.

Tour the Experimental Forest Network in a newly updated story map by Shawna Reid.

For more information, email Chuck Burdine or Bryan Mudder at or

Access the latest publications by SRS scientists.