Comparative analysis on temperature reduction effectiveness of ornamental tree species in University of Port Harcourt

Abstract

The process of urbanization causes alterations in the landscape, affects the environment negatively and the community is placed at risk. In an attempt to sustain urban growth, urban areas have now developed their own urban climate which alters thermal conditions. As the process of urbanization continues to increase in the face of climate change, these problems are likely to be exacerbated. There is a need to find ways to reduce these negative effects. Hence this study aimed to evaluate the effect of five ornamental tree species on temperature reduction in University of Port Harcourt. Five ornamental tree species effectiveness on temperature reduction were comparatively evaluated. Thirty trees in each species were randomly selected and diameter measurements at various points were taken on the selected trees. Temperature readings were taken both under the tree species and on bare ground where there were no planted trees. There was significant difference between temperature under tree and that in bare ground. From the result it was observed that the average temperature reduction due to the presence of trees ranged between 0.64^oc to 2.03^oc. The species were also significantly different in its effectiveness to reduce temperature. Magnifera indica had the highest effectiveness in temperature reduction of 2.03^oc. The result shows that crown diameter and crown projection area influence the amount of temperature a species can effectively reduce. Conclusively, the results suggest that ornamental trees provide environmental benefits in urban area, and these benefits are strongly dependent on the species and planting conditions.

Keywords: Crown, Climate change, Shading, Temperature, Urban environment