A brief overview of the 25-year-old long-term soil productivity study in the south.
The international Long-Term Soil Productivity experiment began in 1989 in response to the need for Forest Service, U.S. Department of Agriculture managers to understand and monitor the impacts of forest management on site productivity given the expected increase in timber harvesting at the time. It grew to include many other cooperators across the U.S. and Canada and today represents the largest coordinated study of forest management and soil productivity in the world. Twenty-five years after its inception, the Gulf Coastal Plain locations provide many important findings and lessons for management. Overall, soil compaction did not reduce early loblolly pine (Pinus taeda L.) survival or growth. In fact, pine volume was increased due to reduced competing vegetation in compacted plots. Intensive organic matter removal (whole-tree harvesting and complete organic matter removal), however, reduced stand volume growth, but only on nutrient-deficient sites. These findings raise questions about current guidelines related to compaction and intensive harvesting. Continued monitoring will help determine how resilient the soils and forests are to these one-time disturbances.