中文摘要：

【目的】森林群落中化感物质挥发途径对其天然更新存在重要影响。马缨杜鹃、迷人杜鹃和露珠杜鹃是贵州百里杜鹃国家森林公园内的先锋种与建群种,收集3个高山杜鹃纯林群落林内空气来探讨化感物质成分,为百里杜鹃林区林下天然更新提供科学依据。【方法】采用典型样方法对自然状态下马缨杜鹃、迷人杜鹃和露珠杜鹃三大主要杜鹃群落做野外调查,计算各样地的Berger-Parker优势度指数、Simpson多样性指数、Pielou均匀度指数,对生物多样性特征进行分析。采用采样气袋法对3个群落林内气体挥发物进行收集,运用固相微萃取气相色谱质谱联用技术分析3个高山杜鹃群落林内气体的化感成分。【结果】3个群落的优势度从高到低为迷人杜鹃、露珠杜鹃、马缨杜鹃,多样性指数从高到低为露珠杜鹃、迷人杜鹃、马缨杜鹃,均匀度指数从高到低为露珠杜鹃、马缨杜鹃、迷人杜鹃。SPME-GC/MS结果显示露珠杜鹃、迷人杜鹃和马缨杜鹃林内气体中分别检出17、13和11种挥发性化感物质成分,其中烷烃类物质是其主要挥发性化感成分;3个杜鹃群落中还有萜烯类、有机酸、酯类、酮类、酚类,这些物质均属于化感物质或具有抑制作用。露珠杜鹃林内气体成分主要包括烷烃类、萜烯类、酮类和酚类等,其中相对含量最高的成分是2,2,4,6,6-五甲基庚烷（30.81%）,较高的成分是5-乙基-2,2,3-三甲基庚烷（19.87%）、癸烷（11.71%）、十二烷（10.00%）。迷人杜鹃林内气体成分主要包括烷烃类、萜烯类、酯类和有机酸类,其中相对含量最高的成分是2,5-二甲基-2,5-过氧化二氢己烷（20.23%）,较高的成分是5-乙基-2,2,3-三甲基正庚烷（18.13%）、十二烷（14.30%）、2,2,7,7-四甲基辛烷（10.20%）。马缨杜鹃林内气体成分主要包括烷烃类、酚类、酯类和有机酸,其中相对含量最高的成分是癸烷（22.92%）,?

英文摘要：

[ Objective ] In forest community, natural regeneration. Rhododendron delavayi, R the volatile pathway of allelochemical has a significant impact on its agastum and R. irroratum are the pioneer and dominant species in Baili Azalea National Forest Park in Guizhou province. Air samples are communities to analyze their allelochemical components, in order to collected from pure forests of the three Rhododendron provide a scientific basis for the natural regeneration of Baili Azalea National Forest Park. [ Method] Field investigations of three major Rhododendron communities （R. delavayi R. agastum and R. irroratum） under natural conditions were conducted using the method of typical sampling plotsBerger-Parker dominance index, sample plots. Based on these Simpson＇ s diversity index, and parameters, hiodiversity of the compounds were collected from the three communities using air Pielou evenness index were calculated for each of the communities were characterized. Samples of volatile bags. Components of the allelochemieals in the Ihree communities were investigated and analyzed by using the solid phase microextraction （SPME） technique and the gas chromatography mass spectrometry （GC/MS）. [ Result ] The Berger-Parker dominance index of the three communities from high to low was R. agastum, R. irroratum and R. delavayi, the Simpson index from high to low was R. irroratum, R. agastum and R. delavayi, and the Pielon index from high to low was R. delavayi, R. irroratum and R. agastum. There were respectively 17, 13 and 11 volatile allelopathy components in the air samples of R. irroratum, R. agastum and R. delavayi identified by SPME-GC/MS, and the main volatile allelopathy component was alkanes in all the three communities. Terpenes, organic acids, esters, ketones and phenols were also detected and they are allelochemicals or have inhibitory effects. The components of R. irroratum community were mainly alkanes, terpenes, ketones and phenols, and the highest component was 2,2,4,6,6-pentamethylheptane （30.81%?