Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA; Herbert Wertheim School of Public Health and Human Longevity Science & Scripps Institution of Oceanography, UC San Diego, San Diego, CA, USA.
Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, CO, USA.
Environ Int. 2023 Aug;178:108050. doi: 10.1016/j.envint.2023.108050. Epub 2023 Jun 19.
Cities often use non-native plants such as turf grass to expand green space. Native plants, however, may require less water and maintenance and have co-benefits for local biodiversity, including pollinators. Previous studies estimating mortality averted by adding green space have not considered the provision of native plants as part of the greening policies.
We aim to estimate premature deaths that would be prevented by the implementation of native-plants policy scenarios in the City of Denver, Colorado, USA.
After conducting interviews with local expert stakeholders, we designed four native-plants policy scenarios: (1) greening 30% of all city census-block groups to the greenness level of native plants, (2) adding 200-foot native-plants buffers around riparian areas, (3) constructing large water retention ponds landscaped with native plants, and (4) greening parking lots. We defined the normalized difference vegetation index (NDVI) corresponding to native plants by measuring the NDVI at locations with known native or highly diverse vegetation. Using a quantitative health-impact assessment approach, we estimated premature mortality averted under each scenario, comparing alternative NDVI with the baseline value.
In the most ambitious scenario, we estimated that 88 (95% uncertainty interval (UI): 20, 128) annual premature deaths would be prevented by greening 30% of the area of census block groups with native plants. We estimated that greening 30% of parking-lot surface with native plants would prevent 14 annual deaths (95% UI: 7, 18), adding the native buffers around riparian areas would prevent 13 annual deaths (95% UI: 2, 20), and adding the proposed stormwater retention ponds would prevent no annual deaths (95% UI: 0, 1).
Using native plants to increase green spaces has the potential to prevent premature deaths in the City of Denver, but results were sensitive to the definition of native plants and the policy scenario.
城市通常会使用非本地植物（如草坪草）来扩大绿地面积。然而，本地植物可能需要更少的水和维护，并且对当地生物多样性（包括传粉媒介）有共同的益处。以前估算通过增加绿地面积来避免的死亡人数的研究并没有将提供本地植物作为绿化政策的一部分来考虑。
我们旨在估算在美国科罗拉多州丹佛市实施本地植物政策情景将避免的过早死亡人数。
在对当地专家利益相关者进行访谈后，我们设计了四个本地植物政策情景：（1）将所有城市普查街区组的 30%绿化到本地植物的绿色水平，（2）在河岸地区周围增加 200 英尺的本地植物缓冲区，（3）建造大型带有本地植物景观的蓄水池塘，以及（4）绿化停车场。我们通过测量具有已知本地或高度多样化植被的地点的归一化差异植被指数（NDVI）来定义与本地植物相对应的 NDVI。使用定量健康影响评估方法，我们根据每个情景估算了避免的过早死亡人数，将替代 NDVI 与基线值进行比较。
在最具野心的情景中，我们估计通过绿化 30%的具有本地植物的普查街区组区域，将预防 88 例（95%置信区间（UI）：20，128）年度过早死亡。我们估计，绿化 30%的停车场表面用本地植物将预防 14 例年度死亡（95% UI：7，18），在河岸地区周围增加本地缓冲区将预防 13 例年度死亡（95% UI：2，20），而增加拟议的雨水滞留池塘将不会预防任何年度死亡（95% UI：0，1）。
使用本地植物来增加绿地面积有可能预防丹佛市的过早死亡，但结果对本地植物的定义和政策情景敏感。
