Long-term soil-ecosystem experiments (LTSEs) demonstrate how soils function and change on time scales of decades. See: http://ltse.env.duke.edu

The Calhoun LTSE in the South Carolina Piedmont USA, was initiated in 1957 by US Forest Service scientists, Drs. LJ Metz and CG Wells. The 16 0.1-ha plots were laid out in old cotton fields and planted with loblolly pine seedlings and samples of soil taken and archived with similar methods on eight occasions (1962, 1968, 1972, 1977, 1982, 1990, 1997, & 2005). The long-term Calhoun study is directly observing the changing biogeochemistry of the ecosystem, now 51 years in age.

The research documents how ecosystem processes and change are controlled by on-going contemporary forest development, but also by legacies of cotton cultivation between 1800 and 1955, and multi-millennial evolution of the natural ecosystem.

In May 2007, half of the 16 permanent plots were clear-cut and are being regenerated with pine seedlings, all to further examine human impacts on soils and ecosystems. The Calhoun Experimental Forest is not only an ecologically significant experiment of human effects on ecosystems, but of natural recovery processes as well.

Calhoun researchers invite collaborations with other scientists, land managers and users, teachers, writers, students, even poets.

Dan Richter, Mac Callaham
Duke University & USDA Forest Service