【作者】 陈旭；

【导师】 王升忠； 卜兆君；

【作者基本信息】 东北师范大学 ， 自然地理学， 2008， 硕士

【摘要】 在哈泥泥炭地调查苔藓典型生境,测量各环境因子和分析泥炭样品的基础上,采用方差比率法、χ2检验、Spearman秩相关和Jaccard指数分析方法对优势植物种间联结进行定量分析,同时采用Levins和Pianka公式和典范对应分析对七种苔藓的生态位及其分异进行研究,初步探讨七种苔藓种间联结与生态位关系。主要结论如下:(1)种间联结结果表明,中位泥炭藓(Sphagnum magellanicum)、锈色泥炭藓(S.fuscum)和桧叶金发藓(Polytrichum juniperinum)之间呈显著正关联,且在开阔地中与小叶杜鹃(Rhododendrom parvifolium)、鹿药(Smilacina japonica)、狭叶杜香(Ledum palustre var. ngustum)的种间联结表现明显一致性,大泥炭藓(S. palustre)与小叶杜鹃、鹿药、狭叶杜香的关联性同这3种苔藓相反。喙叶泥炭藓(S. fallax)和尖叶泥炭藓(S. capilifolium)与其他苔藓主要呈负关联,沼泽皱缩藓(Aulacomnium palustre)与其他苔藓种间联结呈中性;(2)两种生境下的种间联结对比分析发现,郁闭度是影响沼泽植被分布的重要环境因子之一,本文中,在同种生境下重要值大的物种之间通常出现正联结,在两种生境下重要值差异大的物种之间一般表现为负联结;(3)苔藓在各种环境因子梯度上的平均生态位宽度排序为:沼泽皱缩藓(0.677)>喙叶泥炭藓(0.670)>中位泥炭藓(0.661)>尖叶泥炭藓(0.651)=桧叶金发藓(0.651)>大泥炭藓(0.547)>锈色泥炭藓(0.512),7种苔藓中锈色泥炭藓倾向于是特化种,沼泽皱缩藓倾向于是泛化种;(4)各种环境因子的平均重叠值中,以电导率平均重叠值最高(0.9205);三个平均重叠值低的环境因子依次为:水位埋深(0.625)、乔木郁闭度(0.7144)和pH (0.7553),多数苔藓沿着这三个环境因子梯度上产生生态位分异,水位埋深、pH和乔木郁闭度是影响苔藓分布主要环境因子;少数苔藓种对在所有环境因子梯度上重叠值高,反映苔藓之间存在水分协作关系,同时提供了苔藓种间竞争的间接证据,但需要通过移植试验验证。(5)典范对应分析准确地描述苔藓生境分异,七种苔藓中,尖叶泥炭藓、大泥炭藓在乔木郁闭度和pH梯度上,以及喙叶泥炭藓和沼泽皱缩藓在水位埋深梯度上,与其他苔藓分异明显。锈色泥炭藓、桧叶金发藓、中位泥炭藓在各个环境梯度上生态位比较相似;(6)苔藓之间种间正关联同时表现为一个或几个生态位维度上高的重叠值,负关联则比较复杂,由于生境差异导致的负关联种对生态位重叠值低,而由于种间资源竞争引起的负关联种对生态位重叠值高。更多还原

【Abstract】 Based on investigation of typical bryophytes habitats, measurement of environmental factors and analysis of peat samples, the inter-specific relationships were analyzed in the methods including variance ratio,χ2-test , Spearman rank correlation and Jaccard index, and the niches and their differentiations of seven species of bryophyte were researched in the methods including Levins and Pianka formulas and canonical correspondence analysis (CCA). Furthermore, the relationships of interspecific association and niche were discussed. The main conclusions are as following:1)The interspecific association of Sphagnum magellanicum, S. fuscum, and Polytrichum juniperinum was positive, and in open area the interspecific associations were similar between the three bryophyte species and three vascular plants including Rhododendrom parvifolium, Smilacina japonica, Ledum palustre var. ngustum. The interspecific association of S. palustre and the three vascular plants was opposite to the three bryophytes’. The interspecific association of S. fallax and other bryophytes was negative, and S. capilifolium was as same as it. The interspecific association of Aulacomnium palustre and other bryophytes was neutral.2) Through comparison of interspecific association in two habitats, I found that canopy density was one of the most important environmental factors influencing vegetation distribution pattern in Hani Peatland. In this paper, ins open area (or forest edge) habitat the species of higher significant values appeared positive association and the species which have great difference of significant values in two different habitats appeared negative association.3) The niche breadths of the seven bryophytes decreased in the order of A. palustre(0.677)>S. fallax(0.670)>S. magellanicum(0.661)>S. capilifolium(0.651)=P. juniperinum(0.651)>S. palustre(0.547)>S. fuscum(0.512). S. fuscum was niche-specific specie, while A. palustre was niche-general specie.4)From the overall mean overlap values of environmental variables, the maximum occured in electrical conductivity gradient(0.9205) and the three low values occurred in depth to water table (0.625), tree coverage (0.7144)and pH of surface water (0.7553) gradients. Bryophytes niches mostly segregated along these three gradients. Depth to water table, tree coverage and pH were three most important environmental factors influencing distribution of bryophytes. Some bryophytes species-pairs with high overlap values in all niche dimensions lived in similar habitats in order to increase water use efficiency. The high overlap values could offer indirect evidence of competition, however, accurate results could be verified by transplant experiments.5)Canonical Correspondence Analysis accurately described the differentiation of bryophyte habitats. The niche differentiations were more obvious among S. capilifolium, S.palustre in tree coverage and pH gradients, S. fallax and A. palustre in depth to water table gradient. The niches in all environmental dimensions were similar among S.fuscum, P. juniperinum, S. magellanicum.6) The positive association went with large niche overlap in one or more niche dimension. The reasons of negative association were complicated. Firstly, when the habitats of species were different, in this case the niche overlap of the species was low. Secondly, while negative association may be caused by resource competition, the niche overlap of the species is high.更多还原