Abstract Cities around the world are pursuing tree planting as a way to increase tree cover. Despite the growing interest in planting trees as a way to offset climate change, counter the negative impacts of urbanization, and provide benefits to city dwellers, there has not been a recent effort to quantify the number of trees being planted nor the species composition of these plantings. Because ecosystem services and ecosystem threats can transcend municipal boundaries, understanding trends in tree planting at multiple spatial scales is critical. To overcome this knowledge gap, we used a survey to collate recent tree planting data from 52 cities with populations greater than 50,000 people in the Northeastern USA. The four largest cities in our study (New York, Boston, Philadelphia, Washington D.C.) planted over 87% of all the trees that were planted in the region. Smaller cities, which are numerous in region, planted proportionally fewer trees and, in over 40% of the small cities surveyed, planting palettes included invasive tree species, highlighting both a resource and a knowledge gap in smaller cities as compared with larger ones. Regardless of city size, records also illuminated an overreliance on certain genera for specific ecosystem services; nearly 20% of all shade trees were Quercus species and over 50% of ornamental trees were either Syringa or Prunus species. As cities continue to rely on tree-planting as a form of green infrastructure, our results demonstrate that more consideration to establishing diverse planting palettes will be an important way to ensure that ecological resilience is maintained. Achieving this will depend on increased opportunities to collaborate across municipal boundaries and promoting cross-learning from the experiences of more innovative urbanized regions to urban regions with less infrastructure and expertise.

中文翻译：

---

未来的城市森林——美国东北部植树计划调查

摘要 世界各地的城市都在寻求植树作为增加树木覆盖的一种方式。尽管人们越来越关注植树造林作为抵消气候变化、应对城市化的负面影响并为城市居民带来好处的一种方式，但最近还没有努力量化种植的树木数量或这些树木的物种组成。种植。由于生态系统服务和生态系统威胁可以超越城市边界，因此了解多个空间尺度的植树趋势至关重要。为了克服这一知识差距，我们通过一项调查整理了美国东北部人口超过 50,000 人的 52 个城市的近期植树数据。我们研究中的四个最大城市（纽约、波士顿、费城、华盛顿特区）) 种植了该地区种植的所有树木的 87% 以上。区域内众多的小城市种植的树木成比例地较少，并且在超过 40% 的接受调查的小城市中，种植调色板包括入侵树种，突出了小城市与大城市相比的资源和知识差距。无论城市规模如何，记录也表明特定生态系统服务过度依赖某些属；近 20% 的遮荫树是栎属，超过 50% 的观赏树是丁香或李属。随着城市继续依赖植树作为绿色基础设施的一种形式，我们的结果表明，更多地考虑建立多样化的种植调色板将是确保维持生态恢复力的重要方式。