Urban Forest Research & Ecological Disturbance (UFRED) Group, Department of Geography & Environmental Studies, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada.
School of Urban and Regional Planning, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada.
J Environ Manage. 2018 Feb 15;208:24-35. doi: 10.1016/j.jenvman.2017.12.015. Epub 2017 Dec 13.
Urban tree canopy provides a suite of ecological, social, and economic benefits to the residents of urban areas. With an expanding recognition of these benefits among city residents, there is growing concern that access to these benefits is not distributed equally and may represent the presence of an environmental injustice. This study examines the spatial relationship between median household income and tree canopy variables, specifically realized tree canopy cover and potential tree canopy cover, for Toronto, Canada. Toronto provides a strong empirical focus as it is a densely populated urban setting reported to be exhibiting an increase in the geographic polarization of residents based upon household income. Spatial relationships between median household income and tree canopy variables are evaluated using the bivariate Moran's I statistic, a specialized local indicator of spatial autocorrelation (LISA). This method explicitly identified where statistically significant spatial clusters of high and low household income coincide with significant clusters of high and low urban tree canopy, providing the basis for an examination of the policies and management decisions that led to this temporal snapshot. The importance of these spatial clusters is examined from the perspective of understanding the impact of urban change (both socio-demographic and built form), and from the standpoint of improving equality of access to city trees and their benefits resulting from future tree planting decisions.
城市树冠层为城市居民提供了一系列生态、社会和经济效益。随着城市居民对这些益处的认识不断提高，人们越来越担心这些益处的获得并不平等，可能存在环境不公平现象。本研究考察了加拿大多伦多市家庭收入中位数与树冠变量（实际树冠覆盖率和潜在树冠覆盖率）之间的空间关系。多伦多是一个人口密集的城市，据报道，居民的家庭收入存在地域两极分化的趋势，因此成为一个强有力的实证研究焦点。使用二元 Moran's I 统计量（一种特殊的空间自相关局部指标，LISA）来评估家庭收入中位数和树冠变量之间的空间关系。这种方法明确地确定了家庭收入高和低的显著空间聚类与城市树冠高和低的显著聚类在哪里重合，从而为研究导致这一时点的政策和管理决策提供了基础。从理解城市变化（社会人口和建筑形式）的影响的角度，以及从改善未来植树决策中获得城市树木及其效益的机会均等的角度，探讨了这些空间聚类的重要性。
