John C. Calhoun Experimental Forest

The Calhoun Experimental Forest, located in the Sumter National Forest near Union, South Carolina, was established in 1947 for work on serious Piedmont forest, soil, and water problems. The Calhoun’s initial location was determined to represent the “poorest Piedmont conditions” of soil erosion and cropland abandonment. Early studies on the Calhoun were aimed at soil improvement and watershed restoration in order to find the cheapest, quickest, most effective ways to improve tree growth and soil structure, runoff and sedimentation, and increase soil fertility for plants.

Current research includes the long-running collaborative study with Duke University in which the biogeochemistry of soil and vegetation has been monitored, sampled, and archived since 1957. Techniques to control subterranean termites and impacts of even- and uneven-aged management on wood quality. Forests of the Calhoun are actively managed by the National Forest System to allow future research opportunities.

Three seriously eroded watersheds are being re-gaged to continue watershed experiments that began in 1947. The experimental forest has recently become one of the nation's nine Critical Zone Observatories in a long-term project that brings together 15 scientists from six universities, colleges, and the USDA Forest Service.