NIGERIAN JOURNAL OF FORESTRY

This study developed slenderness models for forest plantation and natural forest of Khaya senegalensis in Shaibu Community to foster planting of the tree species in urban and rural communities of Nasarawa State. The specific interest of the research is to develop height diameter models, slenderness coefficient model and examine relationships among the variables of Khaya senegalensis plantation in the Nasarawa State University and the natural forest of of Shaibu Community Forests. Data were collected from randomly selected thirty (30) temporary plots of 0.01ha located in the plantation. Thirty (30) plots of 0.01ha were also selected from the Shabu community forest, Lafia. The data collected include total height and diameter at breast height. The results of height diameter model in the plantation showed that model one (1) with AIC (126.0709), BIC (130.2745) and RSE (1.853) has the lowest model selection indices when compared with the other three (3).

The results of height diameter model in the Khaya senegalenesis natural forest showed that model one (1) with AIC (158.456), BIC (162.6596) and RSE (3.179) has the lowest model selection indices when compared with the other three (3) also. The result of slenderness coefficient model in the Khaya senegalensis plantation showed that model one (1) with AIC (-17.61868), BIC (-13.41509) and RSE (0.169) has the lowest model selection indices when compared with the other two (2) models. The result of slenderness coefficient model in Khaya senegalenesis of the natural forest showed that model one (1) with AIC (-12.91355), BIC (-8.709963) and RSE (0.1827) has the lowest model selection indices when compared with the other two (2) models applied. The correlation between diameter at breast height and slenderness coefficient was negative. This implies that the proportion of trees prone to wind-throw or damage in the area decreases with increase in tree diameter at breast height. The result also revealed that 76.7% (>80 high), 13.3% (70-80 moderate) and 10% (<70 low) in the Khaya senegalensis plantation. The result further unveiled that 23.3% (>80 high), 6.7% (70-80 moderate) and 70% (<70 low) in the Khaya senegalensis natural forest. Khaya senegalensis trees are very valuable for its attractive and durable wood properties. Therefore, effort should be made by the Federal and State Government including NGOs and individuals to managing its natural stands, urban and rural tree planting, particularly around Nasarawa State Communities with less planting density as the result in natural stand showed that less dense planting of Khaya senegalensis is resilient to wind throw which is the major threat in planting many tree species within rural and urban dwellings.


Keywords: Slenderness coefficient, height diameter model, wind throw, Khaya senegalensis.