Publication Information

Past management practices have changed much of the native mixed pinehardwood

forests on upland alluvial terraces of the western Gulf Coastal Plain to either pine

monocultures or hardwood (angiosperm) stands. Changes in dominant tree species can alter

soil chemical, biological, and physical properties and processes, thereby changing soil

attributes, and ultimately, soil functions. Restoring these forests may be slow or difficult if soil

function is altered appreciably. We studied the soil properties and processes in pine or

hardwood-dominated stands after 35 y since conversion from a mixed pine-hardwood stand.

The pine forest floor biomass was about twice as great as that of the oak stands, the oak soils

were 20–30% wetter than the pine soils throughout the sampling period, the oak soils

released more CO2 through respiration and had higher rates of N mineralization in the

summer. We observed few differences between pine and oak stands in soil chemistry or

microbial biomass. Since the difference in forest floor depth and soil biological activity may

confer competitive advantages or disadvantages to some species, this study supports the

hypothesis that pine- or hardwood-only stands create functionally different soils on these site

types after 35 y.