Site quality assessment and yield models for Tectona grandis (Linn. F.) stands in Ibadan metropolis
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Date
2010-12-07
Journal Title
Journal ISSN
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Publisher
Forestry Association of Nigeria (FAN)
Abstract
The study involved site quality assessment and development of yield models for Tectona grandis in Ibadan
metropolis. Five stands of Tectona grandis selected for this study were located at University of Ibadan
Second Gate (UISG), International School Ibadan (ISI), Agodi garden (AG), Oke Baba-agba (OKBA) and
Obegimo (OBGM). Twenty seven temporary sample plots of size 25m×25m were proportionally allocated
to the five stands with respect to their land areas; and the sample plots were randomly located within each
stand. Ten plots in UISG, 2 plots in ISI, 5 plots each, in AG, OKBA and OBGM respectively. Measurement
of tree growth variables (diameters at breast height, base, middle and top, crown diameter and length, total
height, merchantable height and stem quality) of all the trees in each of the plots in the study area were
taken. Ages of the five stands were noted. For the purpose of sight quality estimation, seven largest trees
were chosen from each of the plots as the dominant trees per plots. The measured variables were processed
and used to compute basal areas and stem volume of trees at individual tree and whole-stand levels. The
dominant height-age data set were used to construct site index equation. This was used to estimate site
index values for each of the plots. In addition, volume computed from all the trees within each sample plot
was used to construct yield models at individual tree and whole-stand levels. The site index equation
obtained for site quality assessment in this study was:
SI = ln 7.48 .04 1 Exp H A d .
The most suitable individual tree yield model found was Ln SV = 1.59 + 0.02A + 1.05InBA while the most
suitable whole-stand yield model was InSV = 1.83 – 11.89A-1 + 0.73InBA + 0.07SI.
Description
Keywords
Site quality, Yield Models, Tectona grandis, Dominant height, Tree Volume
Citation
Adeyemi, A. A. and Adesoye, P.O. (2010). Site quality assessment and yield models for Tectona grandis (Linn. F.) stands in Ibadan metropolis. Nigeria Journal of Forestry, 40 (1&2), 67-77