Fifteen-Year Growth Patterns After Thinning a Ponderosa-Jeffrey Pine Plantation in Northeastern California

摘要

Growth was analyzed after one thinning in a plantation of pole-size ponderosa and Jeffrey pines on land having a site index of 50 feet at 50 years. Periodic annual increment was determined for each of three 5-year periods. On this basis, increment in diameter and cubic volume were found to be related closely to stand basal area only. Basal area and height increment, however, were also related to time since thinning; basal area growth decreased and height growth increased with each succeeding period. The optimum basal area for volume production (both cubic and board-foot measures) was estimated to be 110 sq ft/acre. Optimum stocking levels and resulting stand performance are predicted for a common thinning practice.