Identification of suitable trees for urban parks and roadsides in Iskandar Malaysia

Abstract

Urban trees provide a number of benefits, mainly for environment, community, and economy, but can also be harmful to property and human lives. Urban trees planted at roadsides with low endurance rate and unhealthiness increase the risk of tree fracture and fall which is hazardous to motorists and pedestrians. Overhanging limbs, on the other hand, can obscure streetlights, signs and traffic signals and affect road users’ vision in vicinity. These situations contribute to the cumulative maintenance burden to the local authority. This makes the study of maintenance level and suitable location for urban tree planting important. An appropriate maintenance and location can be suggested for assuring a healthy, safe, resilient and long-term survival of urban trees. Urban tree field data from two local authorities in Iskandar Malaysia region (located in the southern part of Peninsular Malaysia), Johor Bahru City Council, and Pasir Gudang Municipal Council, were obtained to achieve the objective of this study. Survey based on questionnaire was conducted to gain detailed information about the maintenance level of existing trees and their suitable locations in the cities from the professionals including urban planners, landscape architects, and certified arborists. By applying a simple scoring method to the data obtained from professionals, suitable locations for existing trees in the two cities were determined. The scores range between 0 and 300 and the highest value means less maintenance is required by the trees. Results show that Mimosup elengi tree species (Sapotaceae family) has the highest score of 300 followed by Cinnamomum verum (297) and Hopea odorata (283). Khaya senegalensis, on the other hand, with 245 score value was found to require high levels of maintenance. The results also indicate that maintenance level and suitable location for planting vary and depending on the features of the tree species. Strongest trees or limbs tend to cause less problems thus require less maintenance. Trees found in the nature (forest) including Mimosup elengi and Cinnamomum verum are usually more resilient and can tolerate a wide range of conditions and locations. This study can help reducing the risk of tree fracture and fall, prolong the life of trees, and reduce the burden of maintenance for local authorities and decision makers by providing insights to the maintenance level and suitable locations for planting and to make better management plans for urban forestry in Malaysia in the future.