Street trees provide ecological and social benefits that sustain urban life, yet their distribution frequently mirrors socioeconomic inequalities, meaning underprivileged social groups also have fewer trees. The distribution patterns of urban trees are least documented in the cities of rapidly evolving middle-income countries. We assessed whether street tree abundance, size, condition, diversity, and composition vary across census-derived socioeconomic strata in Nairobi, Kenya. We sampled 2047 trees across 12 neighborhoods, covering 24 km of street, then used linear regression to understand how socioeconomic strata relate to street tree characteristics. We found substantial disparities in tree abundance, with affluent areas harboring 91.5 % of the trees sampled. Low-income areas and informal settlements had comparably few trees. Mean diameter and condition did not vary across socioeconomic strata, but high-income, formerly European neighborhoods had a higher proportion of small trees, indicating a bias in recent urban greening investments further benefiting these areas. Species diversity followed a similar pattern of inequality. High-income neighborhoods had over 30 % higher species richness and diversity than low-income areas. Even so, lower income neighborhoods exhibited greater differences in street tree community composition, and a higher proportion of trees that bear edible fruit or are used in traditional medicine. Overall, our results reveal pronounced spatial inequality in the distribution of street trees in Nairobi, reflecting not only socioeconomic differences but the enduring legacies of colonial planning.

中文翻译：

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行道树群落反映了肯尼亚内罗毕的社会经济不平等和殖民规划的遗产影响


行道树为维持城市生活提供了生态和社会效益，但它们的分布往往反映了社会经济不平等，这意味着弱势社会群体的树木也较少。在快速发展的中等收入国家的城市中，城市树木的分布模式记录最少。我们评估了肯尼亚内罗毕的行道树丰度、大小、状况、多样性和组成是否因人口普查衍生的社会经济阶层而异。我们对 12 个社区的 2047 棵树进行了采样，覆盖了 24 公里的街道，然后使用线性回归来了解社会经济阶层与行道树特征的关系。我们发现树木丰度存在巨大差异，富裕地区拥有 91.5% 的采样树木。低收入地区和非正规定居点的树木相对较少。平均直径和状况在社会经济阶层之间没有变化，但高收入的、以前的欧洲社区的小树比例更高，这表明最近的城市绿化投资存在偏差，进一步使这些地区受益。物种多样性遵循类似的不平等模式。高收入社区的物种丰富度和多样性比低收入地区高 30% 以上。即便如此，低收入社区在行道树群落组成方面表现出更大的差异，并且结出可食用果实或用于传统医学的树木比例更高。总体而言，我们的结果揭示了内罗毕行道树分布的明显空间不平等，这不仅反映了社会经济差异，还反映了殖民规划的持久遗产。