不同植物群落的空气负离子浓度分布特征及其差异分析

植物群落对空气负离子浓度具有直接影响。本研究于2022年4—12月在太原理工大学植物园开展实地观测,选取8种不同类型的植物群落为研究对象,测定空气负离子浓度、空气温度、相对湿度、PM2.5、PM10等指标,分析不同植物群落空气负离子浓度变化差异及其影响因素。结果表明,(1)不同季节空气负离子浓度的日变化趋势不一致,春季呈上升趋势,其中9：00至10：00和17：00至18：00时段升幅较大,中午时段较为平稳；夏季呈上午上升、中午下降、下午再次上升的变化趋势,并且各植物群落在17：00至18：00时段达到全天最高值；秋季呈现先升高后降低的变化趋势,即早晚时段空气负离子浓度较低,上午 10：00至12：00达到全天最高值；冬季变化不明显。(2)不同植物群落夏季空气负离子浓度值高于春秋两季,且植被组成结构复杂的植物群落高于植被组成结构简单的群落,其中,S4(侧柏Platycladus orientalis+核桃Juglans regia+紫叶李Prunus Cerasifera)和S7(山楂Crataegus pinnatifida)两个植物群落的空气负离子浓度均值高于其他群落。(3)不同植物群落空气负离子浓度与气象因素的相关关系不一致,总体呈现出与空气温度正相关,与相对湿度、PM2.5和PM10负相关的规律。

The analyze of negative air ions distribution characteristics in different plant communities

The concentration of negative air ions was directly impacted by plant community. In order to analyze the negative air ions distribution characteristics and those influencing factors, the 8 different plant communities were chosen in Taiyuan University of Technology botany garden as research objects at April to December in 2022. And then the indicators, such as the content of negative air ions, air temperature, relative humidity, PM2.5 and PM10 were determined. As results, (1) The variation trends of negative air ions were different in the four seasons. In spring, the content of negative air ions showed an upward trend and had a largely rising range at 9:00 ~10:00 am and 17:00 ~ 18:00 pm. In summer, it firstly increased at forenoon, and then declined at noon, and increased again at afternoon; meanwhile, the highest value of the whole day was at 17:00 to 18:00. In fall, it first increased and then decreased, reaching the highest value at 10:00 ~ 12:00. In winter, there were no significantly changes. (2) The negative air ions concentration was higher in summer than that in spring and autumn. However, the plant communities with complex vegetation structure were higher than those with simple vegetation structure. Specifically, the two plant communities, S4 (Platycladus orientalis + Juglans regia + Prunus Cerasifera) and S7 (Crataegus Pinnatifida), showed higher levels of negative air ions concentration than others. (3) The correlation between negative air ions and meteorological factors were different among experimental plant communities. Generally, the negative air ions contents showed positive correlation with air temperature, and negative correlation with relative humidity, PM2.5 and PM10.