南京地区主要森林类型空气负离子变化特征

对南京地区杉木、马尾松、麻栎、毛竹等4种林分中空气负离子含量的变化进行了分析。结果表明,不同林分空气负离子含量的日变化趋势为:杉木、毛竹林呈单峰变化趋势,麻栎呈双峰变化趋势,但差异不显著(p>0.05)。4种林分空气负离子含量月变化趋势基本一致,基本呈单峰变化趋势,即夏季最高,其次是秋季和春季,冬季最低,呈极显著差异(p<0.01)。杉木、马尾松、麻栎、毛竹4种林分空气负离子含量年均值分别为1 234、1 387、1 157、1 198个/cm3。各林分特征指标中,对空气负离子含量影响最大的是郁闭度,其次是生产力,林分垂直结构的影响最小。

Preliminary study of the variation of air anion in different forest stands in Nanjing city

The air anion content of Cunninghamia lanceolata,Quercus acutissima,Phyllostachys pubescens,Pinus massoniana were observered in Nanjing.The results showed that daily variation of the content of air anion had only a singlepeak in C.lanceolata and Ph.pubescens,and a double-peak in Q.acutissima,however the difference of the daily variation of the air anion in the four forest stands were insignificant.The monthly variation of air anion in the four forest stands were similar and performed a single-peak each.Variation of the air anion contents of different seasons in the four forest stands were in a descending order of summer,autumn,spring and winter,the difference was significant.The average content of air anion in C.lanceolata,P.massoniana,Q.acutissima,Ph.pubescens were 1 234,1 387,1 157,1 198 ions/cm3 respectively.The most important factor that affected the content of air anion was crown density,followed by productivity and forest vertical structure.