Correlations and Spatial Variability of Soil Physical Properties in Harvested Piedmont Forests

Soil response to timber harvest trafficking was similar for eroded soils in two locations of the Piedmont of Alabama. Pre-harvest and post-harvest data indicated compaction to be present to a depth of 40 cm as indicated by cone index measurements, with the most significant changes occurring in the upper 20 cm. The degree of spatial dependence differed among soil properties and varied by the site and the specific soil property. Significant correlations existed between individual properties (different properties for each plot) and supported previous research results in regards to the relationship between soil properties and compaction. Coregionalization was present in each site as indicated by the results for co-kriging of correlated properties and indicated that more intensively sampled properties may provide the means to predict the spatial distribution of more difficultly measured soil properties. However, it is unclear which specific conditions promote the greatest degree of compaction, and which site-soil property combinations should be evaluated to provide a better understanding of soil compaction in Piedmont soils.