Soil Morphological, Physical, and Chemical Parameteers Affecting Longleaf Pine (Pinus palustris) Site Quality and Ecosystem Restoration Potential in East Texas.

There has been a large decline in coverage of longleaf pine (Pinus palustis Mill.) within its range since the time of European settlement in the southeastern United States. Due to this decline, interest has developed in the re-establishment of this species on suitable sites. Historically, longleaf pine was found on soils with a wide range of soil properties including higher quality soils due to frequent fires which kept many competing species suppressed. Decline in longleaf coverage has been attributed to many factors including site conversion and fire suppression. Much of the land in the southeastern United States has been converted to agricultural use, loblolly pine plantations, and urban use. Fire has been suppressed for health, safety and liability concerns. Due to limited funding and reduced prescribed fire use, longleaf pine ecosystem restoration efforts should be focused on sites that exhibit soil characteristics that are more favorable to lower risk from herbaceous and hardwood competition. However, there is a need to quantify the potential growth of longleaf pine on these marginal soils.

Soil properties such as texture, pH, buffered pH, depth of argillic horizons, bulk density, available water capacity, extractable macro nutrients, and total carbon and nitrogen of longleaf pine ecosystems located in the Angelina and Sabine National Forest in Texas, as well as the Kisatchie National Forest in Louisiana will be evaluated to develop a better understanding of how various soil variables can be used to determine appropriate sites for successful longleaf pine restoration. Statistical analysis and regression techniques will be utilized in the comparison between the Kistatchie (thermic Typic Hapludults), Letney (thermic Arenic Paleudults), Stringtown (thermic Typic Hapludults) , and Tehran (thermic Grossarenic Paleudults) soil series that varied in texture, depth to the argillic horizon, available nutrients, available water capacity, and site indices will be evaluated on successful and non-successful plantings of longleaf pine. Preliminary results will be presented.