【作者】 雷瑞虎；

【导师】 喻勋林；

【作者基本信息】 中南林业科技大学 ， 植物学， 2008， 硕士

【摘要】 桂花Osmanthus fragrans (Thunb.) Lour.是木犀科木犀属植物,分布于长江流域以南的北亚热带和中亚热带山地,包括湖北、湖南、四川、安徽、江西等省区。目前对桂花群落的研究还很少,多数是关于桂花品种分类和生理的研究。本文对其进行群落学方面的系统研究,在理论上探讨其群落区系、群落结构特征、物种多样性、种间联结等内容,在实践上为桂花的合理利用、保护提供科学依据,也为武陵山地尤其是小溪自然保护区和借母溪自然保护区的桂花保护、合理利用提供理论基础。本文主要研究结果如下：(1)在2000m2调查样地中共有维管束植物90科,188属,275种。群落植物的科属组成不集中,科属系数较大。群落植物区系属于中国-日本森林植物亚区的华中区,区系成分起源古老,地理成分复杂多样。群落植被组成以热带亚洲植物、北温带植物为主要成分,群落植物属热带性起源。(2)群落属于典型的常绿阔叶林(包括常绿-落叶阔叶混交林),浓郁苍翠,林相整齐。群落分层明显,可分为乔木层、灌木层、草本层和层间植物。群落植物的生活型分布格局反映了该地具有温暖湿润的中亚热带气候。采用3个聚集度指标分析群落主要乔木种群的空间格局,主要种呈聚集和随机分布。(3)从种群年龄结构、高度级结构、重要值等方面分析桂花种群。分析表明其年龄、高度级结构均完整合理,密度大,群落正处于稳定的发展状态。桂花重要值高,是群落的优势种,其重要值随着海拔的升高呈现增大的趋势。并按照优势种原则划分的群落的类型。(4)采用5个物种多样性指数对群落进行物种多样性分析。经计算群落的总体多样性指数平均值分别是：Margalef指数F=12.5594,Simpson指数D=0.9754,Shannon-Wiener指数H=3.9027,均匀度指数JS=0.3876,均匀度指数JSW=0.9081。说明了群落物种多样性丰富,在该自然条件下群落表现稳定。(5)用方差比率法VR对乔木层14个主要种群进行总体相关性测定,测定结果：VR=1.4211>1,表现出净的正关联,说明群落正处于稳定阶段。检验统计量W=56.8429,说明关联度小,各种群趋于独立出现。(6)采用共同出现百分率PC和联结系数AC测定乔木层主要种群,并用χ2检验法检验显著性。乔木层14个主要种群组成91个种对,其中呈正联结的有49对,负联结的有42对。桂花与乔木层其它13个主要种群的种间关联分析中,呈正关联的有8对,呈负关联的有5对,有2对达到显著性水平更多还原

【Abstract】 Osmanthus fragrans (Thunb.) Lour. belongs to OLEACEAE and Osmanthus Reinw. Osmanthus fragrans lived in the north and the central subtropical mountainous regions, which belongs to the south of the Yangtze River, including Hubei, Hunan, Sichuan, Anhui, Jiangxi Province, and other provinces. In the present Osmanthus fragrans communities study pretty rarely, but most of studies are about the species classification and physiology. This paper is to systematically study its community. It hopes to theoretically inquiry into some aspects, included its flora, structural features, species diversity and interspecific associations of the communities. And it provides scientific theories for its reasonable exploitation and protection on practicing, also for the Wuling Mountains, especially for Jiemuxi Nature Reserve and Xiaoxi Nature Reserve. This paper mainly results as follows:(1) There are 275 species in plots with the area of 2000m2, belonging to 90 families 188 genera. The species composition is not concentrated, which is belonging to families and genera in community, but the coefficient is big.The flora belong to Centre-China province in Sino-Japanese. The flora has ancient origin and intricate floristic elements. The floristic constituents are mainly included Tropical Asia plant, North Temperate plant. The community plants belong to tropical origin.(2) The community belongs to typical evergreen and broad-leaved forest (included evergreen and decidous broad-leaved forest). The forest outward appearance is verdant and tidy. The vertical structure of the community is obvious, which is composed of arbor layer, shrub layer, herb layer and the vines. The life form reflects that it is warmth moist of medium subtropics weather. Three aggregate indices are used to analysis spatial distribution pattern of dominant arbor populations, which conform to aggregated distribution. It shows distribution of conglomeration and random.(3) Osmanthus fragrans population is analyzed by age structure, high class structure and importance value.It shows that its age structure and high class structure is integrated and reasonable. The density of the population is big. All the population features show that the community is being placed in stable development period. The important value of the Osmanthus fragrans is high. It shows that is dominant population in the community. It has the increasing trend with the increase of the height above elevation. The type of community was divided on the basis of rule of the dominant species.(4) The community is investigated using 5 species diversity indices. The mean of the total species diversity indices are respectively calculated in the community. Richness index F is 12.5594. Simpson index D is 0.9754. Shannon-Weiner index H is 3.9027.Evenness index Js is 0.3876, and evenness index Jsw is 0.9081. And the community is stability at that natural condition.(5) Used variance ratio (VR) to measure 14 main arbor populations, the total related difference is 1.4211, which shows positive correlation among main arbor populations and reflects that the community is in a fairy stable period. The test statistics W=56.8429, which shows very small connection and each population tends to appear in the independence.(6) Based on percentage of co-occurrence (PC), association coefficient (AC) and counteract x2-test, the interspecific associations among main arbor populations, and the interspecific associations between Osmanthus fragrans population are analyzed in the community. 49 species couples among 91 species couples of 114 species have revealed the positive correlations,42 negative correlations.Analysis about Osmanthus fragrans and other 13 mainly arbor populations show positive correlations that has 8 species couple and negative correlationsthat has 5 species couple,2 couple which show extremely significant positive correlation.更多还原