Forest Drainage Research in the Coastal Plain

Tree measurements and soil evaluations indicate that drainage is responsible for nearly doubling the productivity of pine pulpwood in some forest wetlands in the coastal plain. Ditches also provide spoil for roads that subdivide large blocks of land into more easily managed units. Results from a drainage study on wet, sandy soils on the Apalachicola National Forest in northwest Florida demonstrated that the vigor of 20-yr old slash pine trees could be improved considerably in only 3 yr. Main ditches were dug 4-ft deep and 0.5-mile apart; collection ditches were dug 1.5-ft deep and at 330-ft and 660-ft intervals. Neither the differences in collection ditch spacings nor among years after drainage proved meaningful. The rate of tree growth after drainage did exceed expectance significantly based on comparison with the predrainage growth rate. Survey of soils and pond pine tree heights in North Carolina indicated that approximately the same degree of improvement in soil productivity could be obtained there with adequate drainage as in Florida.