【作者】 康华靖；

【导师】 刘鹏；

【作者基本信息】 浙江师范大学 ， 生态学， 2008， 硕士

【摘要】 本文以我国特有的珍稀濒危植物——香果树（Emmenopterys henryi）为研究对象,从群落特征、物种多样性、种群结构、分布格局、群落各层主要优势种热值、种内种间竞争关系、植物体内元素分布以及与土壤养分的关系等几个方面进行了研究,旨在改物种的保护提供理论依据。通过对上述研究结果的分析,得出以下一些结论:1、香果树主要伴生种为具有热带性质的樟科和山茶科的一些物种;该群落乔木层、灌木层、草本层的物种丰富度、多样性、均匀度都偏低,优势度相对较高;其生活型以包括藤本在内的高位芽植物占绝对优势,达75.90%;叶级以中型叶为主,占53.97%,小型叶次之,占36.51%;叶型以单叶占有较大的优势,达74.70%;叶质以纸质叶为主,占63.86%。香果树在群落水平结构上整体成聚集分布状态,垂直结构上明显分成3个亚层。2、香果树种群结构呈纺锤型,幼苗严重不足,种群有衰退的趋势;其更新是以无性繁殖为主;种群格局整体上呈集群分布,但在不同发育阶段,分布格局有所差异:幼树一般为集群分布,中树和大树向随机分布发展,这种分布格局变化与其生物学和生态学特性密切相关;其格局规模介于8m²和32m²之间。分析认为,香果树的种群结构和分布格局受到了多种因素的影响,如群落区域小生境、香果树生物学特征以及人为干扰外等,在以上各因素的综合作用下,使得其种群形成典型的小种群。3、不同种类植物叶的灰分含量（AC）变化较大,介于3.64%～13.51%;不同季节植物叶的AC不同,但无明显的变化规律;群落各层植物叶的平均AC由高到低依次为草本层（10.42%±3.24%）,藤本层（8.56%±2.22%）,乔木层（8.80%±2.69%）,灌木层（6.16%±1.78%）;整体而言,AC较高的植物干重热值（Gross caloric value,GCV）较低,反之则GCV较高。不同种类植物叶的去灰分热值（Ash free caloric value,AFCVC）变化较小,介于28.29～34.21 kJ/g之间;同一层次内常绿植物叶的AFCVC比落叶植物高;各层植物叶的AFCVC由高到低依次为灌木层（32.15±1.61 kJ/g）、乔木层（30.92±1.15kJ/g）、藤本层（30.24±2.33kJ/g）和草本层（30.59±1.63 kJ/g）,但各层次之间差异均未达到显著水平（P＞0.05）;不同季节植物叶的AFCVC以秋季稍高,春季次之,夏季最低。为了探讨生境片断化的影响,对受破坏较轻的生境（H₁）和破坏较严重的生境（H₂）下共有的6种植物叶的热值和AC的进行了比较研究,结果显示,植物叶的热值为H₂＞H₁,而灰分含量H₁＞H₂。4、香果树的生态位宽度最大,香果树与其伴生种生态位的重叠值顺序为:杉木＞红脉钓樟＞山胡椒＞七子花＞尖连蕊茶;对生境要求非常相近的山胡椒、红脉钓樟和尖连蕊茶之间,其生态位重叠值极高。采用Hegyi单木竞争模型的研究结果表明,在早期阶段,香果树的种内竞争强度随径级的增大而增大,但在胸径大于15 cm以后竞争强度开始逐渐降低,这与香果树种群的实际生长情况相一致。种间竞争强度的大小顺序为:香果树＞杉木＞七子花＞红脉钓樟＞山胡椒＞尖连蕊茶。用单木竞争回归模型对香果树种内和种间竞争强度进行了模拟和预测,模拟和预测结果与实验相符。上述两种方法的研究结果表现出较高的一致性,如种内竞争大于种间竞争;种间竞争又以香果树-杉木之间的竞争最大,而香果树-尖连蕊茶之间竞争最小,且两种方法的结果具有一定的互补性。因此,建议在对群落竞争关系的研究中,如能将生态位和单木竞争模型相结合,将更能客观的反映其竞争关系。根据本研究结果建议在经营香果树人工林时,为了给香果树创造一个良好的生存环境,应选择小灌木作为其伴生种,如尖连蕊茶、红脉钓樟、山胡椒等,而不宜选择生长迅速的常绿树种。5、不同样地的土壤中金属含量除K、Fe、Ni、Sb、Cr有所差异,其余元素之间的差异均未达到显著水平（P＜0.05）;香果树不同器官中元素含量的变化趋势基本一致:大量元素在根、茎、皮、叶中含量均为K＞Ca＞Mg;微量元素Fe在根、茎、皮、叶中含量最高,Cu最低;非必需元素Sb在根、茎、皮、叶中含量最高,T1最低;整体来看,香果树不同器官中元素之间的相关性均较小,表现出相互独立性。同时香果树与土壤元素之间的相关性均较小,表现出相互独立性,说明香果树的分布与土壤元素含量的相关性较小。富集系数以Th、k、Ca和Mg较高,其次为T1、Cu、Ba、Cr、Sb、Zn和Ni,Fe和Mn为最低。更多还原

【Abstract】 Emmenopterys henryi,an endemic species in China,is one of the Chinese national second protective wild plants.It is a particular rare,highly severe endangered and protective plant.The biodiversity conservation of E.henryi is timely needed.The communities’ character, the caloric value,ash content and their dynamics in various layer mature leaves of the dominant plant species,the population structure,the distribution pattern,the intra-specific and inter-specific competition,and the element distribution and its relationship with soil nutrients were studied.The main results are as follows:The companion species of E.henryi were evergreen and from Lauraceae and Camelliaceae.The richness index,species diversity index and evenness index in the E.henryi community were low,but ecological dominance index was high.In the community,dominant life form,dominant leaf size,dominant leaf form,dominant leaf texture was phanerophytes, mesophyll,single leaves,herbaceous leaves,respectively and whose percentage was 75.9%, 53.97%,74.70%,63.86%respectively.The second leaf size was microphyll,whose percentage was 36.51%.The tree layer could be easily divided into 3 sublayers in terms of height.The population structure of E.henryi was a spindle type.The age structure of the population of E.henryi was declining due to lack of seedlings.There are two regeneration modes of E.henryi in forest:sexual and asexual reproduction,but the latter was the main mode. As to the distribution pattern of E.henryi,generally speaking,the E.henryi population was clump,but there are differences among various developmental stages:clump for saplings, random for adult trees and big trees.It was related to their biological and ecological characteristics.To increase accuracy,both methods of Greig-Smith and Kershaw were used to analyse the pattern scale of the population of E.henryi.It was showed in the results that the pattern scale was between 8 m~2 and 32 m~2.The ash content(AC)of the species ranged from 3.60%to 17.55%,and varied with plant species and sampling seasons.The AC of autumn and summer were higher than that of spring. The rank order of the average AC in the leaves was the following:herbaceous layer(10.42% ±3.24%)＞liana layer(8.56%±2.22%)＞tree layer(8.80%±2.69%)＞shrub layer(6.16%±1.78%),and the differences among herbaceous layer and shrub layer was found to be significant(P＜0.05).Gross caloric value(GCV)and ash-free caloric values(AFCV)of the species were highest in the autumn.The rank order of average GCV and GCV were the following:shrub layer(32.15±1.61 kJ/g)＞tree layer(30.92±1.15 kJ/g)＞liana layer (30.24±2.33 kJ/g)＞herbaceous layer(30.59±1.63 kJ/g),and the differences among those layers were found not to be significant(P＞0.05).To reflect the effect of fragmentation on the caloric value,the caloric values of six species in different habitats were compared.Gross and ash-free caloric values of six species in fragmentation habitat were all higher,indicating that fragmentation had remarkable influence on the caloric values.The niche breadth of E.henryi was the broadest in the community.The niche overlaps among the species with the same or similar environment requirements were great,such as Lindera glauca,Camellia cuspidate and Litsea rubuonervia Gamble.The niche overlaps were in the order of C.Ianceolata＞L.rubronervia＞L.glauca＞H.miconioides＞C.cuspidate. The results of study of Hegyi’s competition index model for individual tree indicated that the competition intensity increased with the growth of the DBH(diameter at breast height)at early time till DBH was more than 15 centimeter,which accorded with the fact of the population of E.henryi.The competition intensities were in the order of E.henryi＞C.Ianceolata＞H. miconioides＞L.rubronervia＞L.glauca＞C.cuspidate.Relationship between the competition index and the base diameter of objective tree conformed closely to power function, and competition intensity reduced with the growth in base diameter of objective tree.The results by using the two different methods were accordant,for example the competition in intra-species was more intense than that in inter-species and the competition between E.henryi and C.Ianceolata was the most intense in inter-species,while E.henryi and C.cuspidate was least.Synthesizing our results,the authors consider that combined the two methods to study the competition will be better.There were not significant differences of element content among different plots except K、Fe、Ni、Sb、Cr.The content of k、Ca and Mg were higher in macroelement.The content of Fe was highest in microelement,while Cu was lowest.The content of Sb was highest in noessential element,while Tl was lowest.The relativities among the matel elements were all quite low in different organs.The coeffient of enrichment was Th＞k＞Ca＞Mg＞Tl>Cu＞Ba＞Cr＞Sb＞Zn＞Ni＞Fe＞Mn.更多还原