公园不同植物配置群落空气负离子变化特征

Atmospheric Negative Ion Concentration at Parks Configured with Different Plants

【目的】分析公园内不同植物配置类型负离子浓度变化特征,为营造利于人们身心健康的活动场所提供理论依据。【方法】以福州市闽江公园南园为研究样地进行了1周年(2017年9月至2018年8月)的定点检测,选择30个样点,凝练成8个植物配置类型和1个对照点(CK)。研究不同植物配置类型负离子浓度日、逐日、月和季节的变化特征,应用森林空气离子指数法进行分析及评价。【结果】(1)负离子浓度日变化大都呈V/U字型曲线波动,不同植物配置类型之间的负离子日平均总浓度比较:常绿阔叶林>落叶阔叶林>竹林>混交林>棕榈林>草地>常绿针叶林>灌木丛>对照点;(2)不同植物配置负离子浓度逐日变化均受外界气象因素影响较大,负离子浓度会因气象因子的变化,产生较大的波动;(3)负离子浓度月变化曲线均呈现U字型趋势,不同植物配置类型之间负离子年平均总浓度比较:竹林>落叶阔叶林>常绿阔叶林>棕榈林>混交林>常绿针叶林>灌木丛>草地>对照点;(4)同一植物配置类型不同季节负离子浓度在秋季最高,其次是夏季,春季和冬季负离子浓度相近;(5)不同植物配置类型空气质量排序由高到低为:竹林>落叶阔叶林>常绿阔叶林>棕榈林>混交林>常绿针叶林>灌木丛>草地>对照。【结论】在日变化过程中,一天在7∶00～9∶00为负离子浓度最高时段,常绿阔叶林、落叶阔叶林、常绿针叶林、混交林、竹林群落空气负离子浓度均在3 000个·cm^(-3)以上,空气质量评价指数属于优等,是户外活动最佳时间段和最佳的活动场所。

【Objective】Concentration of negative ions in atmosphere at parks configured with different plants was studied with a public health concern.【Method】The South Arena at Minjiang Park in Fuzhou was selected for a year-long,fixed-point monitoring from September 2017 till August 2018 at 30 sampling locations,where 8 types of plants,along with one as control,were configured.The diurnal concentration as well as the daily,monthly,seasonal variations on both positive and negative ion concentrations in the atmosphere at the surroundings of the various plantations were collected for the analysis and evaluation using the forest air ion index method.【Result】(1)The diurnal variation curves on negative ion concentration generally showed a V or U shape,and the averaged magnitudes ranked evergreen broad-leaved forest>deciduous broad-leaved forest>bamboo forest>mixed forest>palm grove>lawn>evergreen coniferous forest>bushes>control.(2)Weather conditions significantly affected the daily variations on negative ion concentration associated with plant configuration.(3)On a monthly basis,the negative ion concentration varied in a U shape curve.Whereas,the annual averages relating to the plant type decreased in the order of bamboo forest>deciduous broad-leaved forest>evergreen broad-leaved forest>palm grove>mixed forest>evergreen coniferous forest>bushes>lawn>control.(4)With respect to the seasons,the negative ion concentration at a specific plant community was the highest in autumn followed by summer,while no significant difference in spring and winter.(5)The air quality at different plant communities ranked in the order of bamboo forest>deciduous broad-leaved forest>evergreen broad-leaved forest>palm grove>mixed forest>evergreen coniferous forest>bushes>lawn>control.【Conclusion】Negative ion concentration in the air at park was the highest between 7∶00 a.m.and 9∶00 a.m.in a day,which would be the most desirable times for outdoor activities.During that period,the areas planted with evergreen broad-leaved,deciduous broad-leaved or evergreen coniferous trees as well as the mixed and bamboo forests were having greater than 3 000 negative ions·cm^-3 with an excellent air quality evaluation index.