The Effect of Trees on Bedrock Weathering, Soil Thickness, and Rock Fragment Occurrence in Ouachita Mountain Soils

The goal of this project is to investigate the relationship between trees, bedrock, and soil properties in upland forests of the Ouachita National Forest, Arkansas IOklahoma. Knowledge gained through this research will permit Petter decisions on forest management relative to maintenance and improvement of soil quality, and carbon sequestration. The emphasis here is on persistent effects on soil morphology (as opposed to more transient biochemical impacts), the relative importance of trees versus other factors in local soil variability, and the role of floralturbation in soil development. This Proposal represents a further development and extension of earlier and ongoing work. Specifically, this project seeks to further investigate variations in soil Iregolith thickness, the interactions between soil thickness and rooting depth and habits of trees, and the potential role of trees as an active agent of soil thickness by promoting weathering and moisture flux as roots penetrate fractures and bedding planes in the underlying bedrock. The project will also investigate the biomechanical effects of trees on soil, with an emphasis on rock fragments via two previously unexplored mechanisms: deposition in stump holes, and rock/ soil displacement by root growth.