Southern pine beetle infestations are associated with soil and site conditions
in the Piedmont and Coastal Plain. High-hazard sites in the Piedmont are
characterized by heavy red clays (fig. 10).
Figure 10.-Soils that contain a high percentage of micaceous
red clays characterize high-hazard sites
in the Piedmont. These problem soils require careful tending.
These sites have a high erosion potential, limit the infiltration and
percolation of water, and restrict root development. Such problem soils
require careful tending to prevent further deterioration of the site.
Intensive site preparation (e.g., root raking, disking) and cultivation
with heavy equipment are recommended only where soils and slopes are suited
for these practices. The application of intensive site preparation methods
should be avoided on slopes greater than 10 percent. Burning and the use
of suitable herbicides appear to be preferable to intensive mechanical
site preparation in regenerating these areas. Abuse of already fragile
sites in the Piedmont will contribute to future insect and disease problems.
Infestations in the Coastal Plain occur more frequently on wet and waterlogged
sites than on well-drained soils. Trees on poorly drained sites are often
deficient in mycorrhizal roots and are, therefore subject to severe physiological
stress during periods of drought. Drainage systems designed to remove
surplus water from low-lying areas will curtail the damage from root diseases
and stem the decline of host pines. Logging damage in low-lying areas
with fine-textured soils can be avoided by diverting operations to sandy
soils during wet periods and using harvesting equipment of low bearing