Advanced SearchSearch Tips
Crown Ratio Models for Tectona grandis (Linn. f) Stands in Osho Forest Reserve, Oyo State, Nigeria
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
Crown Ratio Models for Tectona grandis (Linn. f) Stands in Osho Forest Reserve, Oyo State, Nigeria
Popoola, F.S.; Adesoye, P.O.;
  PDF(new window)
Crown ratio is the ratio of live crown length to tree height. It is often used as an important predictor variable for tree growth equation. It indicates tree vigor and is a useful parameter in forest health assessment. The objective of the study was to develop crown ratio prediction models for Tectona grandis. Based on the data set from the temporary sample plots, several non linear equations including logistics, Chapman Richard and exponential functions were tested. These functions were evaluated in terms of coefficient of determination () and standard error of the estimate (SEE). The significance of the estimated parameters was also verified. Plot of residuals against estimated crown ratios were observed. Although the logistic model had the highest and the least SEE, Chapman-Richard and Exponential functions were observed to be more consistent in their predictive ability; and were therefore recommended for predicting crown ratio in the stand.
crown ratio;tree growth variables;modeling;Tectona grandis;
 Cited by
Adesoye OP, Oluwafemi OA. 2008. Interim Crown Ratio Models for a Mixed Tectona grandis and Gmelina arborea Stand in the University of Ibadan, Nigeria. Research Journal of Forestry 2: 34-42. crossref(new window)

Avery T, Burkhart HE. 2001. Forest Measurements. 5th ed. McGraw- hill, New York.

Clutter JL, Fotson JC, Pienaar LV, Brister GH, Bailey RL. 1983. Timber Management: A Quantitative Approach. John Wiley and sons, New York.

Dyer ME, Burkhart HE. 1987. Compatible Crown Ratio and Crown Height models. Canadian Journal of Forest Research 17: 572-574. crossref(new window)

Hanus MI, Hann DW, Marshal DD. 2000. Predicting Height to Crown Base for Undamaged and Damaged Trees Southwestern Oregon. Research Contribution 29. Forest Research Laboratory, Oregon state University, Covalllis.

Hasenauer H, Monserud RA. 1996. A Crown Ratio Model for Australia Forest. Forest Ecolog And Management 84: 49-60. crossref(new window)

Holdaway M. 1986. Modeling Tree Crown Ratio. Forestry Chronicle Research 29: 621-629.

Kershaw JA, Maguire DA, Hann DW. 1990. Longevity and Duration of Radial Growth in Douglas-fir Branches. Canadian Journal of Forest Research 20: 1690-1695. crossref(new window)

Kozlowski T, Kramer P, Pallardy S. 1991. The Physiological Ecology of Woody Plants. Academic Press, New York.

Laar A, Akca A. 1997. Forest Mensuration. Cuvillier Verlag, Gottingen.

Marshall DD, Johnson GP, Hann DW. 2003. Crown Profile Equations for Stand Grown Western Hemlock in Northwestern Oregon. Canadian Journal of Forest Research 33: 2059-2066. crossref(new window)

McGaughey RJ. 1997. Visualizing Forest Stand Dynamics Using the Stand Visualization System. Proceedings of the 1997 ACSM/ASPRS Annual Convention and Exposition. April 7-10. Seattle, pp 248-257.

Navratil S. 1997. Wind Damage in Thinned Stands. In Proceedings of a Commercial Thinning Workshop. October 17-18. Whitecourt, pp 29-36.