Crown dimensions and stem sectional area growth of some mixed tropical forest tree species in Ghana.

1997

English

The use of tree crown dimensions as indices of tree growth potential has been well documented for many tree species in temperate regions. Crown dimensions are useful in determining growing space and optimum stand density, and for improving the accuracy of tree growth models. However, for mixed tropical forest tree species such information is lacking, not least because the complex structure of such forests makes it difficult and expensive to collect data on tree crowns. Where such data can be collected, however, its usefulness in improving the efficacy of models for forest management cannot be over-emphasized. This paper examines the relationship of the crown dimensions of 5 mixed tropical forest tree species in Ghana to their growth rates. Data on crown diameter and stem diameter were collected from a total of 408 trees in Bobiri Forest Reserve. From these data, crown area, crown volume, diameter increment and sectional area increment (over a period of 10 yr) were calculated. Regressions of stem sectional area increment on projected crown diameter, crown area and crown volume were all highly statistically significant, but crown area was found to be a better predictive variable than the other attributes of crown size. The regressions on crown area explained 18, 49.6, 56.1, 58 and 62% of the total variation in increment for Guarea cedrata, Mansonia altissima, Entandrophragma angolense, Triplochiton scleroxylon and Khaya ivorensis, respectively. In the regres

Foli, E. G.; Ofosu-Asiedu, A.; Agyeman, V. K.; Adam, A. R.