中文摘要：

为评估利用苔藓监测旅游景点内机动车尾气中元素排放量的可行性并筛选适宜的敏感苔藓生物监测物种,对九寨沟世界自然遗产地原始林景点停车场的（该景点机动车尾气排放中心）中心及其向外辐射区域（半径为0m/120m/1000m）共3条带,采集了两种地表乡土苔藓（大羽藓Thuidium cymbifolium和青藓Brachythecium piligerum）植株样品,利用微波消解-等离子体发射光谱（ICP-AES）方法测定了机动车排放尾气中13种元素含量,分析了距离梯度上元素含量的差异性,比较了两藓种对元素的累积能力.发现：（1）在青藓中测定的13种元素中,不同距离上的Al、Ca、Cu、Fe、Mg、Zn、P和S8种元素含量差异显著,不同距离上的K、Mn、Pb、Ni和Cd5种元素含量差异不显著.（2）青藓较大羽藓可检测出更多的元素;对于被检测出的元素,青藓的累积量大于大羽藓,其中累积量最大的元素是Ca,为10874.286μgg-1a-1,最小的是Cu,为5.438μgg-1a-1.（3）元素在南、北向上的累积量大于东向上的累积量.研究表明,苔藓生物监测方法可有效监测旅游景点停车场机动车排放尾气中的典型元素（如Cu、Pb、Ni、Zn、Cd等）含量,青藓较大羽藓能更可靠地监测九寨沟景点机动车尾气中元素种类及排放量,因此是理想的监测藓种.

英文摘要：

Mosses have been reliably used as a bio-indicator for monitoring the heavy metals in atmosphere,but it is unknown whether they can also be sensitively used in monitoring the elements in tail gas from vehicles in and around any scenic spots with relatively low traffic flow.Therefore,a parking lot in the Jiuzhaigou World Natural Heritage Site was selected,which was divided into three monitoring belts arranged outwards in different directions at distance intervals of 0 m,120 m and 1 000 m,and two ground mosses Brachythecium piligerum and Thuidium cymbifolium were collected on each strip.Totally,thirteen elements（A1,S,Ca,P,Cu,Fe,K,Mg,Mn,Pb,Ni,Zn,Cd） were determined by ICP-AES analysis method.The results indicated：（1） K,Mn,Pb,Ni and Cd could not be detected by B.piligerum,while A1,S,Ca,P,Cu,Fe,K and Zn had significant differences in concentration with the distances from the parking lot,the shorter the distance,the larger the accumulation was;（2） Comparing to T.cymbifolium,B.piligerum could detect more elements,the contents showed the significant correlation with the distance,and B.piligerum had greater accumulation of elements than T.cymbifolium;（3） The accumulation of elements by the mosses in the directions of north and south was much larger than that in the east.This study proved that mosses could reliably monitor the elements in the tail gas from vehicles in scenic spots,and B.piligerum was found an ideal moss for this purpose.