Tree size comparison of some important street trees growing at different sites of Karachi City, Pakistan

Abstract

The importance of trees in urban environment is now widely recognized as they cleanse the particulate air pollution and help to make cities and towns more agreeable places to dwell upon. A detailed survey was conducted to study the size of Alstonia scholaris, Azadirachta indica, Bombax ceiba, Cassia fistula, Eucalyptus sp., Ficus benghalensis, Ficus religiosa and Guaiacum officinale trees in the urban environment of Karachi, Pakistan. Results showed a wide range of variation in tree diameter breast height (17.12-65.50 cm) at M. A. Jinnah Road, University Road (near Hassan Square), North Nazimabad and Karachi University Campus, respectively. A. indica, Eucalyptus sp., and F. benghalensis showed less dbh (tree diameter breast height) at M. A. Jinnah Road as compared to University Road (near Hassan Square), North Nazimabad and Karachi University Campus, respectively. G. officinale growing at University Road (near Hassan Square) showed  ess tree dbh as compared to M. A. Jinnah Road and Karachi University campus. Similarly, the tree size of B. ceiba and A. scholaris was recorded less at Nazimabad as compared to M. A. Jinnah Road, University Road (near Hassan Square) and Karachi University Campus, respectively. C. fistula growing at North Nazimabad site showed low tree dbh as compared to University Road (near Hassan Square) site. A. scholaris growing at Karachi University Campus site showed highest dbh value as compared to all studied sites. The tree size of G. officinale was recorded highest at M. A. Jinnah Road as compared to North Nazimabad, University Road (near Hassan Square) and Karachi University Campus, respectively. Whereas, Eucalyptus sp. and F. benghalensis recorded highest dbh at North Nazimabad site as compared to M. A. Jinnah Road, University Road (near Hassan Square) and Karachi University Campus, respectively. More research is needed on these trees for healthy environment of city. The present study recommends for the complete documentation of tree species growing in city. Such information will be useful to identify characteristics that can be used to select tree species that are better suited for planting on other areas of the city. These findings can be helpful for arboriculturists, environmental scientists and town planners when working on plantation in the selected area.

Keywords: Circumference, diameter at breast height, size, roadside tree, urban environment, Pakistan