Although research shows that individuals report higher levels of happiness when viewing green environments, the dose curve describing the impact of greenery on happiness remains undefined. Current literature only presents dose curves representing the associations between stress recovery and tree coverage, and does not explore how this fluctuates for different types of green infrastructure. Using an image-based randomised control trial with 401 participants, this study assesses the impact of levels and types of street greenery on people’s perceptions of happiness. Participants were randomly assigned to rate one of six images representing proportional increments of street greenery coverage (from 0% to 45%) across three greenery configurations – ground level, between buildings, and vertical (on building façades). The results suggest that the highest levels of perceived happiness are obtained from green coverage of between 35% and 45%, at which point the effect levels off. Vertical greenery coverage has a larger impact on perceived happiness than the other two tested configurations, and has a positive linear rather than concave relationship. The study indicates that viewing greater amounts of greenery significantly enhances communities’ perceived happiness, and shows that the relationship is dependent on the type of green infrastructure configuration used.

中文翻译：

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够绿吗？街道绿化水平和类型对感知幸福感影响的剂量反应曲线


尽管研究表明，个人在观看绿色环境时会表现出更高的幸福感，但描述绿色植物对幸福感影响的剂量曲线仍然不确定。目前的文献仅提出了代表应力恢复和树木覆盖率之间关联的剂量曲线，并没有探讨不同类型的绿色基础设施的剂量曲线如何波动。本研究通过对 401 名参与者进行基于图像的随机对照试验，评估了街道绿化水平和类型对人们幸福感的影响。参与者被随机分配对六张图像中的一张进行评分，这些图像代表三种绿化配置（地面、建筑物之间和垂直（建筑物外墙））街道绿化覆盖率的比例增量（从 0% 到 45%）。结果表明，绿色覆盖率在 35% 到 45% 之间时，感知幸福感最高，此时效果趋于平稳。与其他两种测试配置相比，垂直绿化覆盖率对感知幸福感的影响更大，并且具有正线性关系而不是凹关系。研究表明，看到更多的绿色植物可以显着提高社区的幸福感，并表明这种关系取决于所使用的绿色基础设施配置的类型。