重庆地区主要森林类型的空气负离子水平及其评价

Air Anions Content and Its Evaluation for Main Forest Types in Chongqing

利用便携式空气负离子测定仪（AIC1000）．对重庆地区6种主要森林类型的41个监测点进行为期1a的空气负离子监测和研究。结果表明：各森林类型均能显著提高空气负离子水平（P〈0．01），从大到小依次为针叶混交林、落叶阔叶林、常绿阔叶林、针叶纯林、竹林、针阔混交林、对照（解放碑商务区）：常绿阔叶林和针叶混交林在晴天时的空气负离子水平显著高于阴天和雨天的（P〈0．01），而落叶阔叶林却相反：天气阴晴对其它森林类型的空气负离子影响则不显著（P〉0．05）。各森林类型的空气负离子呈明显的季节变化（P〈0．01），针阔混交林、常绿阔叶林和针叶混交林均以春季最大，落叶阔叶林则以秋季最大；除竹林和针叶混交林外，其它森林类型均以冬季最小。研究监测点的空气负离子水平以V等级（400～1000个·cm-3）为主，以四面山自然保护区的空气质量最好。

With AIC1000 portable air anions tester, the air anion concentration of six main forest types had been measured in 41 monitoring plots of Chongqing in 2012. All forest types significantly can improve air anion content （ P〈0. 01 ）. The order of content is mixed conifer forest〉deciduous broad-leaved forest〉evergreen broad-leaved forest〉coniferous forest〉bamboo forest〉mixed conifer-broadleaved forest〉CK （Jiefangbei Business District）. For evergreen broad-leaved forest and mixed conifer forest, the air anions content in sunny day is higher than that in cloudy day and rain day （P〈0.01）, but it is in contrast for deciduous broad-leaved forest, and the weather conditions has not a significant effect on air anions content of other forest types （P〉0.05）. Air anions of every forest types presents an obviously seasonal variation （P〈0. O1 ）. The air anions content is the most in spring for mixed conifer-broadleaved forest, evergreen broad-leaved forest and mixed conifer forest, but it is the most in autumn for deciduous broad-leaved forest. Except bamboo forest and mixed conifer forest, air anions of other forest types are the least in winter. The air anions content mainly located in the grade of V level （ 400- 1 000 air anions/cm-3 ） in the monitoring spots, and the air quality of Simian Mountains Nature Reserve is the best in all monitoring spots.