Abstract Urban forests provide a variety of ecosystem services that influence environmental and social welfare, but variable distribution of urban tree canopy (UTC) within and among urban areas can lead to inequitable provisioning of these benefits. Variation in UTC among and within urban areas is associated with local development patterns and socio-economic factors as well as broad-scale variation in the biophysical and socio-cultural context of urban regions. The objective of this study was to evaluate regional and continental trends in UTC distribution within and among urban areas, including assessing relationships of UTC and UTC inequality with socio-economic/demographic factors and characteristics of urban regions. Remotely-sensed UTC assessments and US Census data were used to derive census block group-level UTC-related response variables (e.g., percent UTC, inequality in UTC) and socio-economic/demographic predictor variables (e.g., median income, population density) for forty U.S. cities spanning several biophysical and socio-cultural regions. Multiple regression analysis was used to analyze relationships of UTC with socio-economic/demographic predictor variables and the strength of these relationships was compared among cities across regions. There was a significant negative relationship (R2 = 0.45) between total UTC and UTC inequality across the 40 cities, as the equality of UTC distribution within cities increased with decreasing total UTC. There was significant variation across biophysical and socio-cultural regions in UTC, UTC inequality, and the strength of the correlation of fine scale UTC with socio-economic/demographic factors. These findings illustrate the important role of broad-scale biophysical and socio-cultural factors as drivers of UTC patterns within and among cities.

中文翻译：

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评估城市树冠和不平等的宏观模式

摘要 城市森林提供各种影响环境和社会福利的生态系统服务，但城市树冠 (UTC) 在城市地区内部和之间的可变分布会导致这些收益的不公平供应。城市地区之间和城市内 UTC 的变化与当地发展模式和社会经济因素以及城市地区生物物理和社会文化背景的广泛变化有关。本研究的目的是评估城市地区内和城市间 UTC 分布的区域和大陆趋势，包括评估 UTC 和 UTC 不平等与社会经济/人口因素和城市地区特征的关系。遥感 UTC 评估和美国人口普查数据用于推导人口普查区块组级别的 UTC 相关响应变量（例如 例如，UTC 百分比、UTC 中的不平等）和跨越多个生物物理和社会文化区域的四十个美国城市的社会经济/人口预测变量（例如，收入中位数、人口密度）。多元回归分析用于分析 UTC 与社会经济/人口预测变量的关系，并在不同地区的城市之间比较这些关系的强度。UTC 总数与 40 个城市的 UTC 不平等之间存在显着的负相关（R2 = 0.45），因为城市内 UTC 分布的平等性随着 UTC 总数的减少而增加。UTC、UTC 不平等以及精细尺度 UTC 与社会经济/人口因素的相关强度在生物物理和社会文化区域之间存在显着差异。