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

Author: William W. Oliver

Publisher:

Published: 1979

Total Pages: 16

ISBN-13:

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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 he 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 ft2/acre. Optimum stocking levels and resulting stand performance are predicted for a common thinning practice.

Growth of Planted Ponderosa Pine Thinned to Different Stocking Levels in Northern California
Growth of Planted Ponderosa Pine Thinned to Different Stocking Levels in Northern California

Author: William W. Oliver

Publisher:

Published: 1979

Total Pages: 20

ISBN-13:

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Growth was strongly related to growing stock level (GSL) for 5 years after thinning 20-year-old poles on Site Index50 115 land at the Elliot Ranch Plantation in northern California. Five GSL's- basal areas anticipated when trees average 10 inches d. b. h. or more - ranging from 40 to 160 square feet per acre were tested. Periodic annual increment (PAI) in diameter decreased curvilinearly from 0.51 to 0.21 inch, with increasing GSL's from 40 to 160. But only trees in plots heavily thinned to GSL 40 (and briefly in GSL 70) grew faster in diameter after thinning than these same trees grew before thinning. PAI in basal area and net volume rose steadily with increasing GSL9s, reaching 9.0 square feet and 255 cubic feet per acre, respectively, at GSL 160. Apparently, even light thinning reduced volume production, but thinning still is recommended to shorten time until first commercial entry and to promote stand health.