Effect on Plant Cover and Soil Properties

Preparing areas for planting conifer seedlings reduces competition for site resources but creates poor range conditions. Bare soil, low plant cover, and Little forage do not support forest grazing programs. At Boyd Hill on the Modoc National Forest, in California, several regeneration sites were prepared in 1988. Early in 1989 they were planted with ponderosa pine (Pinus ponderosa) seedlings. On five plantations that swnmer, live plant cover averaged just 2.5 percent. Except for shrubs, which covered 1.4 percent of the surface, cover values for plant groups (perennial grasses, annual grasses, perennial forbs, and annual forbs) were less than 0.5 percent each. Non 4 plant area included 53 percent bare soil and 34 percent litter. Rock, wood, and gravel each occupied around 3.5 percent of the surface. For the surface layer, average soil properties on the plantations were: bulk density-1.05 g/cm l, organic matter-l 1.7 percent, soil water-8.1 pereent, and water a~ sorption-O.98 min/em