WHO Collaborating Centre for Environmental Health Impact Assessment, School of Public Health, Curtin University, Perth, Western Australia 6102, Australia.
Fenner School of Environment and Society, Australian National University, Canberra, ACT 0200, Australia.
Int J Environ Res Public Health. 2018 Jul 22;15(7):1547. doi: 10.3390/ijerph15071547.
A move towards more compact and climate-resilient cities is being encouraged around the world. As part of these plans, there is a need to manage the potential conflict between increasing urban densities and the extent of tree canopy in cities. Reductions in tree canopy are a major contributor to the urban heat island (UHI) effect, which will act to reduce rather than increase climate resilience in many cities. A systems thinking approach called Collaborative Conceptual Modelling was used to study the interaction between urban infill, tree canopy, and human health in Perth, Australia. The results indicated that under current planning policies and development practices, the behaviour of the system is dominated by the drive towards higher housing densities. While this may result in the attainment of urban infill targets, it is likely to lead to a reduction in tree canopy, higher temperatures, and a decrease in a range of other benefits provided by trees. Recommended actions to overcome this behaviour were determined by the identification of leverage points in the system. These included a shift to a sustainable development paradigm that places greater value on the environmental and social benefits provided by trees and a greater emphasis on a climate-resilient future. Market and legislative mechanisms should be integrated into the city's greening strategy and development plans to ensure the protection of existing trees and the inclusion of new trees on public and private land.
全球范围内正在鼓励向更加紧凑和适应气候变化的城市发展。在这些计划中，需要管理城市密度增加和树冠覆盖范围之间潜在的冲突。树冠减少是城市热岛（UHI）效应的主要原因之一，这将导致许多城市的气候适应能力降低而不是增加。一种称为协作概念建模的系统思维方法被用于研究澳大利亚珀斯的城市填充、树冠和人类健康之间的相互作用。结果表明，在当前的规划政策和发展实践下，系统的行为主要受到提高住房密度的驱动。虽然这可能实现城市填充目标，但很可能导致树冠减少、温度升高以及树木提供的其他一系列益处减少。通过确定系统中的杠杆点来确定克服这种行为的建议措施。这些措施包括转向更重视树木带来的环境和社会效益的可持续发展范式，以及更加注重气候适应能力的未来。应将市场和立法机制纳入城市绿化战略和发展计划中，以确保保护现有树木，并在公共和私人土地上增加新的树木。
