Cities are human-dominated ecosystems where landscape transformation decreases biodiversity, a conservation concern when urbanization sprawls into biodiversity hotspots with high endemism. We aimed to evaluate the effects of site-specific features such as size and shape of green spaces, land cover, and vegetation on bird species richness in Medellín, Colombia, a city of Northern Andes (n = 44 urban green spaces sampled from February 2018 to February 2019). We found 255 plant species: 23 % of trees and 41 % of understory were native sensu stricto (local origin); most native species and individuals were in green spaces lacking vegetation management. Bird species richness (25.80 ± 8.05 resident species per sampling point; 83 resident species overall) increased towards larger and more regular-shaped urban green spaces (squared or rounded), with less percentage of impervious surfaces and more of grass–shrubs, and less influence of introduced trees in habitat structure (i.e. less crown coverage, basal area, and average height). Bird species richness also increased when richness or abundance of native understory vegetation sensu lato (local or regional origin) increased, but introduced trees dominance represented higher and most significant effects to explain bird species richness. Increasing edge effects across urban green spaces and human-related habitat transformation favoring non-native vegetation might represent significant constraints for enhancing local biodiversity in highly developed Andean cities.

城市是人类主导的生态系统，其中景观改造减少了生物多样性，当城市化蔓延到具有高度地方性的生物多样性热点时，这是一个保护问题。我们旨在评估特定地点特征的影响，例如绿地的大小和形状、土地覆盖和植被对哥伦比亚麦德林（安第斯山脉北部城市）鸟类物种丰富度的影响（n = 2018 年 2 月采样的 44 个城市绿地至 2019 年 2 月）。我们发现了 255 种植物：23 % 的树木和 41 % 的林下植物是本地严格意义上的（当地产地）；大多数本地物种和个体生活在缺乏植被管理的绿色空间中。鸟类物种丰富度（每个采样点 25.80 ± 8.05 种常驻物种；总共 83 种常驻物种）向更大、形状更规则的城市绿地（方形或圆形）增加，不透水表面的百分比较低，草灌木较多，较少引入树木对栖息地结构的影响（即较少的树冠覆盖、基部面积和平均高度）。鸟类物种丰富度也增加了丰富的时或本机林下植被丰意义上拉托（本地或区域起源）增加，但引入的树木优势代表了解释鸟类物种丰富度的更高和最显着的影响。在高度发达的安第斯城市中，城市绿地边缘效应的增加和人类相关的栖息地转变有利于非本土植被，可能是增强当地生物多样性的重大制约因素。