Abstract: Different forms of plant landscapes in urban parks can affect the concentrations of particulate matter (PM) and negative ions (NAI) in the air, which in turn affect human health. In this study, we investigated the effects of five plant landscapes with different characteristics in Shenyang Dongling Park on human comfort by constructing a human comfort index model based on PM and NAI concentrations during July to October 2019. The results showed that plant landscapes had a significant effect on PM concentrations (P<0.05), but did not affect NAI concentrations (P>0.05). The underlying surface without hard pavement was more effective in reducing PM concentration in the landscape space, while the semi-open space form was more conducive to NAI  production. The human comfort index of different plant landscapes showed an initial increasing and then decreasing trend, with the period of 16:00-19:00 being the most comfortable time during a day. In addition,  structure of tree-shrub-herb, the underlying surface without hard pavement, and the semi-open spatial characteristic were beneficial to improving human comfort. Compared with the traditional comfort model, considering PM and NAI as influencing factors for human comfort evaluation  to an average reduction of 11.66% in comfort hours across landscape spaces. Therefore, it is necessary to consider not only the impacts of plant landscape on microclimate, but also the influence of different plant spaces on PM and NAI to create a green space more suitable for visitors’ activities.

Key words: green space, semi-open space, atmospheric particulate matter, air negative ion, human comfort.