Earticle

초록

영어

This paper examined different 2-parameter and 3-parmeter nonlinear models for height-diameter prediction that incorporated different stands variable for the development of robust generalised height-diameter models. Stratified random sampling was employed in selecting 54 sample plots (20 m by 20 m) for six different age series (6, 9, 13, 15, 17 and 21 years old) plantation. Diameter at breast height (D), total height (h) and merchantable height (hm) for individual trees with D≥10 cm were measured. The Nonlinear model forms were fitted by ordinary nonlinear least square (ONLS) regression to select the base model without random parameters. Stands variables where then incorporated as random components for mixed-effects modelling using Gauss-Newton algorithm for nonlinear (weighted) least-squares. The best models were adjured using Standard error of estimate (SEE), Root means square (RMSE) and Akaike’s Information Criterion (AIC) and validated by Z-Score values and residual plot. The overall best height-diameter prediction equation for 2-parameter and 3-parameter estimate was Meyer function and Logistic models respectively. All the parameters of the models predicted at p＜0.05 are significant justifying the use of this model for future predictions in the study area expect for Prodan model. The nonlinear mixed effects yield model developed are efficient and biologically logical in predicting yield of teak in the study area, therefore enabling forest managers to optimise harvest planning, plantation regeneration and management in Area J4 of Omo Forest Reserve.

목차

Abstract
Introduction
Materials and Methods
Study area
Data collection
Results
Nonlinear individual height-diameter equations fit indices
Generalised height-diameter equations and fit indices
Generalised mixed-effect height-diameter equations
Validation for generalised fixed and mixed-effect height-diameter equations
Discussion
Conclusion
References

키워드

저자

• Olayinka Daniel Popoola [ Department of Social and Environmental Forestry, University of Ibadan, Ibadan 200005, Nigeria ] Corresponding Author
• Peter Oluwagbemiga Ige [ Department of Social and Environmental Forestry, University of Ibadan, Ibadan 200005, Nigeria ]
• Angela Unna Chukwu [ Department of Statistics, University of Ibadan, Ibadan 200005, Nigeria ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  Journal of Forest and Environmental Science [산림과학연구]

• 간기

  계간

• pISSN

  2288-9744

• eISSN

  2288-9752

• 수록기간

  1981~2026

• 등재여부

  KCI 등재

• 십진분류

  KDC 526 DDC 634