雷州半岛2种速生人工林内外 PM2.5与空气负离子浓度日变化特征

以雷州半岛2种速生人工林(湿加松和尾巨桉)为研究对象，对林内外 PM2.5与空气负离子浓度进行动态监测分析，研究不同天气状况下人工林内外 PM2.5与空气负离子浓度日变化特征。结果表明：两种林分林内外空气负离子浓度在11：00—13：00较低，傍晚17：00较高；PM2.5同空气负离子特征相反，最高值出现在中午，最低值出现在傍晚；PM2.5同空气负离子浓度呈显著负相关，PM2.5随着空气负离子浓度增加而降低；PM2.5受天气变化影响显著，3种天气状况下的 PM2.5由低到高依次为：雨后晴天>晴天>阴天。

Diurnal Variations in the PM 2.5 and Negative Air Ion Concentrations of Two Kinds of Plantations in Leizhou Peninsula

Taking two kinds of plantations (Pinus elliottii ×P. caribaea, Eucalyptus urophylla ×E. grandis) in Leizhou Peninsula as the study subjects, the diurnal variations characteristics of PM2.5 and negative air ion concentrations were analyzed. The results showed that: average negative air ion concentration was lowest between 11:00 and 13:00 and highest during the early evening (17:00); PM2.5 was opposite to the negative air ion concentrations of air, the highest values of PM2.5 appeared at noon, the lowest values occurred in the evening. The relationship between PM2.5 and negative air ion concentrations was significant with the PM2.5 level generally decreasing as the negative air ion concentrations increased. The PM2.5 level was also significantly affected by the weather, with the highest PM2.5 values being recorded on cloudy days and the lowest being recorded on sunny days occurring just after rainy days.