Hilgardia
Hilgardia
Hilgardia
University of California
Hilgardia

Tree Taper Model Volume Equations: II. Tree Taper Models for Major Commercial California Conifers

Authors

Lee C. Wensel
Craig M. Olson

Authors Affiliations

Lee C. Wensel was Professor, Department of Environmental Science Policy and Management, University of California, Berkeley, CA 94720; Craig M. Olson was Research Associate, Department of Environmental Science Policy and Management, University of California, Berkeley, CA 94720.

Publication Information

Hilgardia 62(3):1-16. DOI:10.3733/hilg.v62n03p016. December 1995.

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Abstract

Equations are developed for eight conifer species to estimate the stem taper of inside-bark diameters from breast height to the tip of the tree. Separate equations are developed to estimate the diameter inside bark at the stump. Equations are fitted and tested on separate halves of a data set composed of tree taper data from previous studies, both from the forest industry and USDA Forest Service surveys. This composite data set extends from Southern California to the National Forests of southern Oregon.

After an extensive examination of existing taper equations, two taper equations were selected for further analysis, one by Biging and the other by Wensel and Krumland. Coefficients for both equations are given for the eight conifer species examined. Because of a lower residual sum of squares, and a lack of correlation of the residual with the available predictors, the Wensel and Krumland equation is recommended for use.

Literature Cited

Amidon E. L. A general taper functional form to predict bole volume for five mixed conifer species in California. For. Sci. 1984. 30(1):166-71.

Biging G. S. Volume tables for young-growth mixed conifers of northern California. 1981. Northern California Forest Yield Cooperative, University of California, Berkeley, Department of Forestry and Resource Management. 56p. Research Note No. 2

Biging G. S. Taper equations for second-growth mixed conifers of northern California. For. Sci. 1984. 30(4):1103-17.

Daubenmire R. F. Alpine timberlines of the Americas and their interpretation. Butler Univ. Bot. Stud. 1954. 11:119-36.

Dolph K. L. Prediction of periodic basal area increment for young-growth mixed conifers in the Sierra Nevada 1988. USDA Forest Service Research Paper PSW-190

Dolph K. L. Nonlinear equations for predicting diameter inside bark at breast height for young-growth Red Fir in California and southern Oregon 1989. USDA Forest Service Research Note PSW-409

Ernst S., Pong W. Y. Lumber recovery from ponderosa pine in northern California 1985. USDA Forest Service Research Paper PNW-333, Portland, Oregon

Kozak A., Munro D. D., Smith J. H. G. Taper functions and their application in forest inventory. For. Chron. 1969. 45(4):278-83.

Kozak A. A variable-exponent taper equation. Can. J. For. Res. 1988. 18:1363-68. DOI: 10.1139/x88-213 [CrossRef]

Max T. A., Burkhart H. E. Segmented polynomial regression applied to taper equations. For. Sci. 1976. 22(3):283-89.

McTague J. P., Stansfield W. F. Total and merchantable volume equations and taper functions for southwestern ponderosa pine. West J. Appl. For. 1988. 3(4):123-25.

Oliver W. W. Ten-year growth response of a California red and white fir sawtimber stand to several thinning intensities. West J. Appl. For. 1988. 3(2):41-43.

Pong W. Y. Lumber recovery from young-growth red and white fir in northern California 1982. Research Paper PNW - 300, USDA Forest Service, Pordand, Oregon

Pong W. Y., Cahil J. M. Lumber recovery from incense cedar in central California 1988. Research Paper PNW - 393, USDA Forest Service, Pordand, Oregon

Stadelman C. R5 Taper Equations 1986. Working draft of the taper table equation development, R5, USDA Forest Service

Walters D. K., Hann D. W. Taper equations for six conifer species in southwest Oregon 1986. p.41. Oregon State University Forest Research Lab Research Bulletin 56, Corvallis, OR

Wensel L. C. Volume tables for young-growth conifers in the northern regions of California. 1977. University of California. Division of Agricultural Sciences Bulletin 1883

Wensel L. C., Daugherty P. J., Meerschaert W. J. CACTOS User’s Guide: The California Conifer Timber Output Simulator, University of California, Division of Agricultural Sciences Bulletin 1920, 91pp 1986.

Wensel L. C., Krumland B. Volume and taper relationships for redwood, Douglas-fir, and other conifers in California’s north coast University of California, Division of Agricultural Sciences Bulletin 1907 1983.

Wensel L. C., Krumland B. E., Meerschaert W. J. CRYPTOS User’s Guide: Cooperative Redwood Yield Project Timber Output Simulator. Bulletin 1924. 1987. Berkeley: Agricultural Experiment Station, University of California. 89p.

Wensel L. C., Meerschaert W. J., Biging G. S. Tree height and diameter models for Northern California conifers. Hilgardia. 1987. 55(8):20

Wensel L. C., Olson C. M. Bark taper equations for California conifers. Hilgardia. 1995. 62(2):14 (Published concurrently and bound in this volume.) DOI: 10.3733/hilg.v62n02p014 [CrossRef]

Wensel L, Olson C. 1995. Tree Taper Model Volume Equations: II. Tree Taper Models for Major Commercial California Conifers. Hilgardia 62(3):1-16. DOI:10.3733/hilg.v62n03p016
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