Relationship between negative air ions and environmental factors in the urban forest parks of Yangzhou in urban and suburban areas

• We analyzed the seasonal variation of NAI in different forest parks. • Through Pearson’s correlation analysis, we explored the correlation between the NAI and the seven impact factors. • We used a random forest model to further identify the main factors influencing NAI concentration. Negative air ions (NAIs) play an important role in human well-being, serving as key indicators of air cleanliness and contributing to both psychological and physiological health. This study aims to investigate the factors influencing NAI concentration in urban and suburban forest parks, enhancing our understanding of the correlation between NAIs and environmental factors. Songjiacheng Urban Forest Park and Runyang Wetland Suburban Forest Park in Yangzhou City were selected as the subjects of this research, and continuous measurements of NAI concentration were conducted over a three-year period. Additionally, seven meteorological factors were monitored. A random forest model was employed to analyze and compare the data from the two forest parks, identifying the environmental factors with significant impacts on NAI concentration. The results indicate that in Songjiacheng Urban Forest Park, NAIs exhibited significant sensitivity to temperature, followed by atmospheric pressure. Conversely, in Runyang Wetland Suburban Forest Park, PM2.5 (particulate matter 2.5) exerted the greatest impact on NAIs, followed by humidity. We conducted a thorough analysis of data to explore the intricate connections between negative air ions and a variety of environmental factors within two urban forest parks. Our findings have significantly broadened our perspective on the characteristics of Negative Air Ions (NAIs) and their management implications within these urban green spaces. This enhanced understanding is pivotal for developing more effective strategies for environmental stewardship and the preservation of these vital urban ecosystems.