Herbage Standing Crop Around Eastern Redcedar Trees

Abstract

The effect of eastern redcedar (Juniperus virginiana) on understory herbage standing crop was investigated in northcentral Oklahoma tallgrass prairies. Herbage standing crop was measured under and at distances radiating away from individual trees of 2 height classes (2 m and 6 m) in 1984 and 1985. Soil water content at 2 distances from eastern redcedar trees and tree leaf water content were examined from 1982 to 1984. There was marked reduction in herbage production beneath the tree canopy, only slight reduction at the dripline, and little herbage reduction beyond the dripline. Tree height did not significantly influence herbage standing crop. Thus, herbage reduction is directly related to tree canopy area. Therefore, herbage reduction would be minimal in the early stages of tree encroachment when canopy is small. Soil water content at the tree dripline was sometimes lower than that 3 m outside the dripline, but the differences were small. Leaf water content generally followed the seasonal trend of soil water content. Burning in late spring is an appropriate prescription for eastern redcedar control since leaf water content is relatively low in late spring.