春夏季温州雁荡山杉木林臭氧质量浓度垂直变化特征

Ozone concentrations of three different vertical gradients for a Cunninghamia lanceolata forest in spring and summer at Yandang Mountain National Forest Park,Wenzhou

森林中臭氧浓度不仅影响林木生长,也影响游憩环境质量,是森林康养环境研究的热点之一。根据2017年春夏两季对温州雁荡山国家森林公园内杉木Cunninghamia lanceolata林不同垂直高度臭氧浓度及气象因子昼夜24 h同步监测数据,分析了不同高度臭氧浓度的变化规律及其影响因素。结果表明:除春季H3(林冠上层)臭氧质量浓度日最大8 h均值达到中国二类环境功能区质量要求外(≤200μg·m-3),两季节中其余各高度臭氧质量浓度日最大8 h均值及小时均值均达到中国一类环境功能区质量要求(≤160μg·m-3);春夏两季各高度臭氧质量浓度从小到大依次为H1(距地面1.5 m), H2(林冠中部)和H3,且春季H1, H2和H3臭氧质量浓度日均值差值高于夏季;两季各高度臭氧质量浓度均为日间高、夜间低,且高值出现于11:00-15:00,低值出现于5:00;春夏两季各高度臭氧质量浓度小时均值与温度、风速呈正相关,与相对湿度呈负相关;春季各高度臭氧质量浓度与气压呈负相关。总体来讲,在雁荡山杉木林环境中,以臭氧质量浓度变化规律为游憩及游憩设施布设标准,在时间的选择上,夏季比春季更适合出游,且夜间优于白天;在空间的选择上,建议选择林下及树冠中部布置游憩设施,如林下栈道及空中栈道或森林木屋等设施。

Research on ozone concentration in forests has become a hot area of forest recreation because of its influence on forest growth and environmental quality.The variation of ozone mass concentration at different vertical heights in forest environment has a guiding role in forest recreation activities.Ozone concentration and meteorological factors in three different vertical gradients(The following are expressed by H1,H2 and H3 respectively.H1 stands for 1.5 m from ground,H2 indicates the central part of canopy,H3 means the boundary between canopy and atmosphere.)in Yandang Mountain were monitored for 24 h in the spring and summer of 2017.Their changing features and influencing factors were also observed at the same time.In this experiment,ozone sampler was used to sample three kinds of ozone mass concentration,and the data were processed by variance analysis and multiple comparison analysis.Results indicated that the mean value of 8 h maximum ozone concentration in three different vertical gradients all achieved the primary standard for ambient air quality standards(100μg·m-3)except for the top of H3(103.03μg·m-3)during the spring.Ozone concentration changes for the different vertical gradients was H1<H2<H3 in both spring and summer with differences in the daily mean ozone concentration between H1 and H2 and H3 being higher in spring than in summer,there was a significant difference between H2 and H3(P<0.05).During the observation period for the two seasons,the daily ozone concentration in the different vertical gradients(H1,H2,and H3)all exhibited a single peak curve,with the highest concentration occurring in 11:00-15:00,whereas the lowest occurring in 5:00.The mean value of the hourly ozone concentration for H1,H2,and H3 during the two seasons was positively related with temperature and wind speed and negatively with humidity as well as pressure.In conclusion,Taking ozone concentration as recreation standard,summer nights was more suitable for people to travel.It was advisable to choose the understory and the middle of the canopy to arrange recreation facilities,such as a plank road in the understory or overhead and a wooden house in a C.lanceolata forest.[Ch,4 fig.1 tab.37 ref.].