中文摘要：

附生苔藓植物是森林生物多样性的重要组分，对森林及其环境的质量有很好的指示作用．为了揭示旅游活动对森林及其环境的影响，调查了九寨沟原始森林景点内附近旅游活动频繁地段与未扰动地段原始林优势种岷江冷杉（Abiesfaxoniana）树干4个高度附生苔藓种类的组成、生物量和群落结构，采用独立样本t检验对苔藓层结构参数进行了差异性检验．结果表明：（1）冷杉树干附生苔藓物种组成在旅游活动频繁地段与未扰动地段有很大的差异．在旅游活动频繁地段，耐荫喜湿物种局部消失（重要值下降），耐干旱抗干扰的植物种群扩大；（2）旅游活动频繁地段树干附生苔藓植物的丰富度、盖度和生物量较未扰动地段小；（3）距地面较高的高度120cm和180cm处受到的干扰强度最大，基部的影响较小．旅游活动对附生苔藓植物的干扰主要为问接的环境影响，其机理还未充分认识，还需进一步研究．综合分析表明，旅游干扰影响了几寨沟的生态环境，需要进一步加强管理，控制游客数量和规范游客行为．图2表3参25

英文摘要：

To determine the long-term effect of tourism on epiphytic bryophytes, species composition, coverage and biomass of the bryophyte community growing on Abiesfaxoniana trees in primary forests in the Jiuzhaigou, a World Nature Heritage site, in Sichuan, China were investigated. Difference in species composition on tree trunks in the two different areas was tested by comparing dominant value of each species. Independent-samples t test analysis was used to examine richness, coverage and biomass of the epiphytic bryophytes community along four tree trunk heights （20 cm, 50 cm, 120 cm and 180 cm） in the two areas. The results showed： （1） there were significant difference in species composition between the two areas. Hygrophilous species disappeared partly, and disturbance-resistant species and exotic species expanded their populations in the tourism area; （2） the community structure of bryophytes on the fir trunks in the tourism area was found simpler than that in the undisturbed area; and （3） the trunk at height of 120 - 180 cm was more susceptible to disturbance, but the base was not affected significantly by disturbance. The results indicated that tourism disturbance altered species composition structure and biomass mostly through indirect impacts. Mechanism of tourism impact on epiphytic bryophytes needs further study. It is necessary to strengthen tourism management, limit the number of tourists and regulate the behaviors of tourists. Fig 2, Tab 3, Ref25