Delta Experimental Forest

Southeast entrance to the Delta Experimental Forest. (Forest Service photo)

The 1,044-ha Delta Experimental Forest, located in Washington County, is owned by the State of Mississippi. In August 1, 1945, the USDA Forest Service entered into a cooperative agreement (effective indefinitely) to conduct research there. The forest is about 5 km north of Stoneville, which is home to the Mississippi Agricultural and Forestry Experiment Station’s Delta Branch, the USDA Agricultural Research Service’s Jamie Whitten Delta States Research Center, and the Forest Service’s Southern Research Station’s Center for Bottomland Hardwoods Research. The Delta also serves as the state-run Stoneville Wildlife Management Area, which offers deer, turkey, and small game hunting in season. The forest is drained by a network of ditches established in the 1930s and is surrounded by agricultural land. It was managed for research purposes and timber production until the 1970s when management stopped. No cutting is allowed without the approval of Mississippi State University.

Research during the first 30 years or so involved thinning studies, development of silvicultural methods aimed at growing quality southern hardwoods, evaluation of progeny tests for improved clones of eastern cottonwood, heart-rot progression studies, and studies of insect borer life cycles and damage to hardwood products. Studies in the 1980s and 1990s included determining the causes of oak decline and investigating southern red oak-sweetgum stand dynamics. Several ice storms occurred in the 1990s; the worst (February 1994) severely damaged the crowns of most canopy trees, which devalued the Delta for forest management research.

Climate

The Delta has a long growing season that extends from mid- to late March until late October or early November. Average annual precipitation is 1,354 mm, of which 45 percent occurs from April to September. Summers are warm and humid, with July having the highest average temperature (34 °C). Winters are mild, January being the coldest month, with an average temperature of 0 °C. Accumulation of snow is rare, though ice storms occur occasionally. Stoneville is 39 m above sea level.

Soils

Soils are largely Sharkey clays interspersed with Dowling clays. Sharkey and Dowling soils are medium acid to neutral, dark, poorly drained, clayey soils in depressions. They are plastic when wet, and hard when dry, forming cracks.

Learn more about official soil series descriptions at the USDA Natural Resource Conservation Service website.

Vegetation

Timber types are elm-ash-hackberry, overcup oak-water/hickory, and sweetgum-water oak. Understory vegetation is composed of eastern swamp privet, swamp dogwood, poison-ivy, greenbrier, blackberry, peppervine, grapevine, and nonnative Chinese privet and Japanese honeysuckle.

Long-Term Databases

There are a few long-term thinning studies.

Research, Past and Present

Nuttall oak plantation. (Forest Service photo)

The Delta Experimental Forest has been and continues to be an important venue for forestry research. Past projects include studies of: bottomland hardwood natural regeneration; bottomland hardwood plantation site- species suitability; progeny evaluations for selecting genetically improved hardwoods; thinning and intermediate stand management; disease and insect spread and control; hardwood insect borer life cycles; red oak-sweet gum stand dynamics; and bottomland hardwood growth and yield.

Mallodon dasystomus and Alaus oculatus larvae. (Forest Service photo)

Currently, the compound, a pesticide-free area surrounded by forest, is used as a facility to rear woodboring insects. Studies include: determining the quantity and species composition of woodborers known to have been favored by Ivory-billed Woodpeckers; mass-rearing the hardwood stump borer (Mallodon dasystomus) for pheromone studies; and rearing potential competitors of the invasive, exotic woodwasp, Sirex noctilio.

Major Research Accomplishments and Effects on Management

Research at the Delta provided much of what we know about species-site relationships on poorly drained, less-fertile Mississippi River alluvial soils.

Several eastern cottonwood clones, selected during the 1960s and 1970s by geneticists at the Southern Hardwoods Laboratory and tested on the forest, are still used throughout the southeastern United States by forest industry and by state and federal agencies and internationally.

Hardwood borer rearing cages. (Forest Service photo)

Eastern cottonwood clone bank. (Forest Service photo)

Collaborators

Collaborators include researchers from Mississippi State University, The University of Mississippi, Yale University, and the U.S. Geological Survey, working in cooperation with U.S. Fish and Wildlife Service, Mississippi Forestry Commission, Arkansas Game and Fish Commission, Anderson-Tully Company, as well as private forestry consultants and industrial foresters.

Research Opportunities

Butt rot during harvest in the late 1990s. (Forest Service photo)

Much of the Delta was cut in the late 1990s to regenerate forest stands that had been unmanaged for more than 30 years. Oak seedlings were planted to supplement natural oak regeneration. The Southern Hardwoods Laboratory in Stoneville has facilities for visiting scientists interested in conducting oak regeneration or hardwood stand dynamics research.

Facilities

The Delta has a 2.2-ha fenced compound with warehouse and utilization buildings. The forest is accessible by blacktop roads at two locations and has about 8 km of all-weather, gravel roads.

Lat/lon: 33°28'8"N, 90°54'W (View this location on a map)

Contact Information

Delta Experimental Forest
USDA Forest Service
Southern Research Station
P.O. Box 227
Stoneville, MS 38776

Tel: 662-336-4800
Tel: 662-336-4831
Fax: 662-336-4829