The Southern Research Station of the USDA Forest Service manages 19 experimental forests that function as living, transpiring laboratories. They are scattered across 10 states, separated by hundreds of miles, and many are approaching 80 years old. Most of them are located on national forests.
Five years ago, SRS began linking the 19 experimental forests into a network.
However, there are still gaps. “We have knowledge gaps and we have geographic gaps,” says Stephanie Laseter, network co-lead and science liaison for the Forest Service Southern Region.
Laseter and Johnny Boggs, SRS scientist and network co-lead, are recruiting cooperating forests that will improve the entire Network by addressing these geographic gaps.
The first cooperating experimental forest to join the network is the Hill Demonstration Forest (DF). Hill DF is located in the slate belt of the Piedmont ecoregion and is owned and managed by North Carolina State University. Nearby experimental forests do not represent the Piedmont – which is growing quickly and includes many metropolitan areas – very well.
Representativeness was not a criterion when experimental forests were established. “As with many historic networks, the process was more intuitive,” says Boggs.
The most extreme environments of the South – the deserts of western Texas, the swamps and marshes of Florida, and a few other areas – are not well represented. But most of the South is well represented, as several analyses by SRS scientists show.
Each experimental forest was established to solve a specific problem. For example, the resins that pine trees produce were once used to waterproof wooden ships. In the 1930s, Olustee Experimental Forest (EF) was an important research site for these resins, which are called naval stores. A tree breeding program to select for trees that produce more resin was established, and it was so successful that it led to a broader breeding program for resistance to fusiform rust disease and other traits. Research on the Olustee EF laid the foundation for the establishment of seed orchards throughout the South.
The Calhoun EF became an experimental forest in 1947 because of its soil erosion. A century of farming led to unchecked erosion and created gullies and canyons across the 2,000 acres that now make up the Calhoun EF. Research was initially devoted to improving the soil so that it could once again store water and sustain plants.
Calhoun EF receives the least rainfall each year – about 1100 mm (43 inches). Boggs and Laseter are hoping to add new cooperating experimental forests in dry areas.
Research questions of today are at a different scale than questions in the 1930s and 1940s, when many of the experimental forests were established.
“A lot of our work today occurs at regional scales,” says Boggs. Regional studies mean experimental forests must represent their surrounding landscapes. The representativeness analysis for the Experimental Forest Network was conducted by SRS scientists William Hargrove and Bill Christie and Jitu Kumar, a researcher at Oak Ridge National Laboratory.
Hargrove and Christie are developing a map that will show which areas each experimental forest represents. “Eventually, managers will be able to plug in latitude and longitude and find the experimental forest most similar to theirs,” says Boggs.
Managers in northern Louisiana, for example, might not look to the Palustris EF, even though it is in their state. The Crossett EF is across a state line, in Arkansas. It is in the upper West Gulf Coastal Plain and represents some parts of Louisiana better than the Palustris EF. Similarly, there are experimental forests in Texas, Mississippi, Alabama, and Florida that also represent some areas of Louisiana.
There are eight experimental forests in the western part of the South: Alum Creek EF, Crossett EF, Koen EF, and Sylamore EF, in Arkansas; Palustris EF, in Louisiana; Delta EF and Tallahatchie EF, in Mississippi; and Stephen F. Austin EF, in Texas.
In the eastern part of the region, there are 12 experimental forests: Escambia EF, in Alabama; Chipola EF and Olustee EF, in Florida; Hitchiti EF and Scull Shoals EF, in Georgia; Harrison EF, in Mississippi; Bent Creek EF, Blue Valley EF, Calhoun EF, Coweeta Hydrologic Laboratory, and Hill DF, in North Carolina; and Santee EF, in South Carolina.
Across the U.S., the Forest Service manages 84 experimental forests and ranges. Visit an interactive map to explore these locations.