Urban forest cover change and sustainability of Malaysian cities

Abstract

Despite their significant role for biological diversity, ecosystem stability and human comfortability, tree coverage in cities is continuously destructed and degraded to cater to increasing urbanisation in developing countries, including Malaysia. Cities are more susceptible to environmental change impacts and become unlivable. Thus, monitoring and mapping tree cover is critical (i) for conserving trees and (ii) for making decisions to increase green cover in cities. Mapping and monitoring urban green cover can be done routinely using remote sensing technologies. In this study, tree cover data produced by the University of Maryland, USA using Landsat satellite imagery was used to assess the tree cover changes in four cities, namely Penang Island, Kuala Lumpur and two cities in Iskandar Malaysia in Peninsular Malaysia. The 30 m x 30 m ground resolution tree cover data were overlaid onto the city boundaries to calculate the losses and gains in tree cover relative to the tree cover in the year 2000. Results of the study show that over a period of 12 years (2000-2012), Penang, Kuala Lumpur, Johor Bahru and Pasir Gudang lost about 6.9 %, 3.5 %, 9.5 % and 17.4 % of tree cover from their total land area. Nevertheless, these areas also gained some tree cover over the same period, which resulted in a net loss of 723 ha, 494 ha, 2,366 ha and 3,678 ha. From 2012 to 2014, the total loss of tree cover in the 4 cities were 138 ha, 64 ha, 626 ha and 1,159 ha, respectively. The loss of tree cover in cities needs to be controlled and efforts should be taken to plant more trees in Malaysia. Although the importance of green space within urban areas is more noticeable recently in Malaysia, no specific policies and legislation relevant to the protection and management of urban forests are available. Clear and detailed urban forest strategies and policies must be formulated to protect, plant and manage the urban forests in Malaysia.