【摘要】 负氧离子（NOI）浓度在评价人类对森林康养环境的舒适性方面发挥着重要作用。为探索城郊森林环境空气负氧离子水平，以南昌市城郊针阔混交林为研究对象，从2021年1月至12月，在24 h内实时对NOI浓度及空气PM_2.5含量、温度和相对湿度进行长期定位监测，研究分析针阔混交林内负氧离子浓度及其影响因子，以探索NOI的时间动态变化关系。结果表明：1)负氧离子浓度年平均值为1 786个/cm³,达到Ⅱ级清新标准，对人体有益；2)林内负氧离子浓度日变化表现为“双峰单谷”趋势，即05:00负氧离子浓度最高，17:00次高，12:00负氧离子浓度最低，无日照时段内的浓度高于有日照时段；3)受季节变化的影响，林内负氧离子浓度特征表现为秋季>冬季>夏季>春季；4)相关性分析结果显示，负氧离子浓度与空气PM_2.5含量呈负相关，与空气相对湿度呈正相关，但空气温度对其影响不明显。研究结果可为开展城市林业生态效益评估及市民安排户外运动和森林康养活动提供参考。更多还原

【Abstract】 Concentration of air negative oxygen ions（NOI） plays an important role in evaluating forest health effects and promoting human physical and mental health.In order to explore the level of negative oxygen ions in the air of urban forest environment, this study took coniferous and broad-leaved mixed forest in the suburbs of Nanchang city as the research object, and conducted long-term on-site monitoring of NOI concentration, air PM_2.5 content, temperature and relative humidity within 24 hours from January 2021 to December 2021.The negative oxygen ion concentration and its influencing factors in coniferous and broad-leaved mixed forest were analyzed to explore the temporal dynamic mode of NOI.The results showed as follows: 1)The average annual concentration of NOI in the forest was 1786 ind/cm³,which reached the level ⅱ fresh standard and was beneficial to human body; 2)The diurnal variation of NOI concentration in the forest showed a "double-peak and single valley" trend, that was, the concentration of NOI was the highest at 05:00,the second highest at 17:00,and the lowest at 12:00,and the concentration in the period without sunshine was higher than that in the period with sunshine; 3)Due to the seasonal changes, the NOI concentration was characterized as autumn>winter>summer>spring; 4)Correlation analysis results showed that NOI concentration was negatively correlated with air PM_2.5 content and positively correlated with relative humidity, but temperature had no obvious effect.These results can provide references for assessing the ecological benefits of urban forestry and for citizens to arrange outdoor sports and forest conservation activities.更多还原