Crown Ratio Models for Tectona grandis (Linn. f) Stands in Osho Forest Reserve, Oyo State, Nigeria
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초록
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 (R2) 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 R2 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.
Abstract
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 (R2) 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 R2 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.
참고문헌 (13)
- Adesoye OP, "Interim Crown Ratio Models for a Mixed Tectona grandis and Gmelina arborea Stand in the University of Ibadan, Nigeria", Research Journal of Forestry, 2, pp.34~42 (2008)
- Avery T, "Forest Measurements. 5th ed" (2001), McGraw-hill
- Clutter JL, "Timber Management: A Quantitative Approach" (1983), John Wiley and sons
- Dyer ME, "Compatible Crown Ratio and Crown Height models", Canadian Journal of Forest Research, 17, pp.572~574 (1987)
- Predicting Height to Crown Base for Undamaged and Damaged Trees Southwestern Oregon, "Hanus MI", Forest Research Laboratory, Oregon state University, ~, pp.Research Contribution 29 (2000)
- Hasenauer H, "A Crown Ratio Model for Australia Forest", Forest Ecolog And Management, 84, pp.49~60 (1996)
- Holdaway M, "Modeling Tree Crown Ratio", Forestry Chronicle Research, 29, pp.621~629 (1986)
- Kershaw JA, "Longevity and Duration of Radial Growth in Douglas-fir Branches", Canadian Journal of Forest Research, 20, pp.1690~1695 (1990)
- Kozlowski T, "The Physiological Ecology of Woody Plants" (1991), Academic Press
- Laar A, "Forest Mensuration" (1997), Cuvillier Verlag
- Marshall DD, "Crown Profile Equations for Stand Grown Western Hemlock in Northwestern Oregon", Canadian Journal of Forest Research, 33, pp.2059~2066 (2003)
- McGaughey RJ, "Visualizing Forest Stand Dynamics Using the Stand Visualization System", Proceedings of the 1997 ACSM, 1997, 248~257
- Navratil S, "Wind Damage in Thinned Stands", Proceedings of a Commercial Thinning Workshop, pp.29~36 (1997)