Seasonal Variation of Volatile Organic Compounds and Negative Air Ions in Liquidambar formosana Stand and Their Effect on Microbial Populations

To reveal the species of volatile organic compounds (VOCs) released by Liquidambar formosana, the bacteriostatic effect of VOCs and the purifying effect of air, the composition and content of single Liquidambar formosana and Liquidambar formosana forest were analyzed and identified by thermal desorption gas chromatography-mass spectrometry (TDS-GC-MS),The results showed that there were 26 kinds of 3 types compounds from VOCs of single tree, mainly limonene, myrcene, β-pinene, etc., terpenes accounted for 96.0% of the total VOCs. There were 28 kinds of 7 types compounds from VOCs in the stand, including terpenes and benzene, among them, there were 21 kinds of 5 types of VOCs in spring and summer, 6 kinds of 4 types in autumn. Kinds and content of VOCs differed with seasons, total release in summer was 1.2 and 69.5 time of that in spring and autumn. The negative air ion concentration in stand in spring, summer and autumn increased by 61.8%, 68.7% and 29.5% compared with that in the control (open space). Compared with the control, in spring, summer and autumn, the bacterial content decreased by 27.9%, 49.5% and 18.9%, while in spring and summer, the fungal content decreased by 21.4% and 38.3% respectively.