By: ADEKUNLE V. J.;
Abstract:
Growth measurement of plantation species is very important to afforestation projects and models are necessary for sustainable management of forest ecosystems. Tree growth variables were assessed and compared for four 23-year old plantation species (Gmelina arborea, Pinus caribaea, Terminalia superba and Triplochiton scleroxylon )in this study and models for estimating their volumes were developed. Data were collected from ten equal size plots (25 x 25m) randomly located in stands of each species and linear regression models were fitted for species. Comparison of tree growth variables was done with the one-way analysis of variance and all the models were assessed and validated. The results revealed that the indigenous species are better than the exotic ones in terms of dbh and height growth only but higher stocking were recorded for the exotic species due to lower mortality in the stands of the exotic species. Terminalia superba has the highest mean and dominant dbh (39.55 and 56.55 cm respectively) while the least was recorded for Pinus carbaea (25.41 and 41.41 cm respectively). Gmelina arborea has the highest volume/ha (497.02 m3 ) and the least was obtained for Terminalia superba (168.58 m3 ). The ANOVA results show a significant difference (p<0.05) in the species’ growth characteristics. The selected models that were recommended for each of the species have good fit and are very suitable for stand volume estimation in this location and in other locations with similar edaphic and environmental factors. Adequate maintenance of the stands and establishment of permanent sampling plots to monitor growth were suggested.
Keywords: Plantation, Volume Equations, Forest Stand, Reserves, Dominant Diameter
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