Assessment of Tree Vigour Models in University of Port Harcourt Park

Abstract

Trees are the unsung heroes of the environment that requires care and maintenance so as to continue its provision of quantifiable benefits. Hence a better understanding of the physical aspect of tree mechanics would help to provide basis for the proper management of trees. The study assessed the vigour of selected trees in University of Port Harcourt Park. Data were collected from four selected tree species based on their abundance in the study area. Tree growth parameters were measured and tree vigour estimated using live crown ratio. Different regression functions were used to model tree vigour. The selected tree species used were Terminalia mantaly, Azadirachta indica, Mangifera indica and Terminalia cattapa with frequency of 214 (32.8%), 123 (18.89%), 82 (12.60%)  and 79 (12.14%) relatively. Tree growth parameters such as height, Diameter at breast height, crown variable measured showed significant correlation with tree vigour (live crown ratio). The prediction models revealed plausible regression coefficient of determination (R2) value ranging from 0.247 - 0.953 and standard Error of Estimate (SEE) ranging from 0.0003 – 6.209. From the validation test, it was observed that all the models were good in prediction. However, the double log function was selected as the best model with R2 value of 0.953 and SEE value 0f 0.0003. Conclusively the trees within the University of Port Harcourt Park are stable hence are not prone to wind throw.