崇明东滩莎草科植物群落格局及其形成机制研究

发布时间：2017-12-30 21:45

本文关键词：崇明东滩莎草科植物群落格局及其形成机制研究　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：盐沼在全球分布广泛,环境梯度明显,物种组成较简单,且具有较为明显的分带现象,其植物群落的空间格局一直是生态学研究的热点问题。叇草、海三棱叇草以及糙叶苔草是崇明东滩三种主要的莎草科土著植物,在盐沼湿地中具有重要的生态系统功能。然而,近年来莎草科植物群落受到围垦、污染以及生物入侵等威胁,分布面积骤减。区别于以往在大尺度上对盐沼植物分带机制的研究,本研究在盆栽受控实验的基础上,在小尺度上对崇明东滩南部环境因子的空间自相关性以及莎草科植物与环境因子的关系进行了调查,还探究了崇明东滩湿地前沿先锋物种的分布格局以及种内、种间竞争的效应,以进一步加深对盐沼植物群落组织机制的理解。本研究的主要结果如下:(1)崇明东滩南部团结沙环境因子时空变异大,生境异质性程度高。各向同性模型下,含水量和硝态氮具有强烈的空间自相关性,而电导率具有中等程度空间自相关性,容重和铵态氮空间自相关性很弱。各向异性模型下,各环境因子的块金值、基台值均相同,但是含水量、电导率、铵态氮以及硝态氮的变程差异大,容重变程差异最小。含水量在5月和11月显著高于7 月(one-way ANOVA,P0.05);电导率和硝态氮季节差异显著(one-way ANOVA,P0.0S),11月最高,7月最低;容重在5月显著高于7月和11月(one-way ANOVA,P0.05);铵态氮在7月显著高于5月和11月(one-way ANOVA,P0.05);总无机氮在11月显著高于5月和7月(one-way ANOVA,P0.05)。海三棱叇草适宜分布于土壤含水量和容重较高而电导率较低的生境,叇草在土壤含水量较高、电导率较低和容重较低的生境中占优势,而糙叶苔草适宜分布于土壤电导率较高、含水量低、氨态氮浓度较低的生境中。(2)克隆植物在不同生长阶段,种群密度在不断发生变化,种内竞争强度也随之改变,因此,植物会采取相应的生长策略和调节方式。整个生长季中,海三棱叇草以及糙叶苔草在不同初始栽种密度处理下的密度增长有极显著差异(repeated measurement ANOVA,P0.01)。收获时,糙叶苔草在中、高密度处理下种群密度显著高于低密度处理(one-way ANOVA,P0.05),中密度处理下冠层高度显著高于低、高密度处理(one-way ANOVA,P0.05)。叇草和海三棱叇草的单株生物量与密度呈显著负相关(R2=0.541,P0.05;R2=0.520,P0.05),叇草和糙叶苔草的总生物量与密度呈显著的正相关(R2=0.525,P0.05;R2=0.508,P0.05),根冠比则均未随密度发生显著变化。三种莎草科植物在中、高密度处理下均表现为竞争关系,且高密度处理下的竞争强度显著高于中密度处理(one-way ANOVA,P0.05)。(3)莎草科植物萌生苗对实生苗具有显著的竞争抑制作用,同时也受到实生苗的抑制作用。在整个生长季中,海三棱叇草实生苗在单种及与叇草萌生苗混种处理下高度增长有显著差异(repeated measurementANOVA,P0.05),而与糙叶苔草以及海三棱叇草萌生苗混种时则无显著差异。海三棱叇草实生苗与叇草萌生苗混种时,在生长季中后期密度低于单种,但差异不显著;与糙叶苔草萌生苗混种时,在整个生长季内海三棱叇草实生苗密度均低于单种,二者差异极显著(repeated measurement ANOVA,P0.01)。叇草、糙叶苔草以及海三棱叇草萌生苗在单种及混种处理下高度增长均无显著差异,时间和竞争的交互作用对糙叶苔草萌生苗高度增长具有极显著效应(repeated measurementANOVA,P0.01)。三种植物的萌生苗在单种及混种处理下密度增长均具有极显著差异(repeated measurement ANOVA,P0.01)。生长季末收获时,与海三棱叇草实生苗的竞争使叇草萌生苗地上生物量显著降低(one-way ANOVA,P0.05),而叇草萌生苗的竞争效应显著降低了海三棱叇草实生苗的最高高度和冠层高度(one-way ANOVA,P0.05)。海三棱叇草实生苗的竞争效应显著降低了糙叶苔草萌生苗的最高高度、密度以及地上生物量(one-way ANOVA,P0.05),而海三棱叇草实生苗密度和地上生物量也受到糙叶苔草萌生苗的显著抑制(one-way ANOVA,P0.05)。莎草科植物实生苗和萌生苗之间存在着强烈的种间竞争关系,且这种竞争是不对称的,在糙叶苔草萌生苗-海三棱叇草实生苗混种处理中,萌生苗受到的竞争效应显著高于实生苗(one-way ANOVA,P0.05)。(4)环境因子在小尺度上的斑块性和异质性对盐沼植物的分布格局具有重要影响,而植物的种内、种间相互作用也直接影响植物的繁殖生长表现。因此,在对莎草科植物群落进行保护和修复时,我们只有全面综合考虑影响莎草科植物繁殖生长表现的各种因素,才能较为准确的了解植物群落的组成结构和动态变化,为盐沼湿地的保护和修复提供依据。
[Abstract]:Salt marsh is widely distributed in the earth, the environmental gradient obviously, species composition is relatively simple, and has obvious zonation, the spatial pattern of the community has been a hot issue of ecology. Cloudy sky grass, bulrush grass and Carex scaberrimus cloudy sky is Chongming Dongtan three main Cyperaceae native plants, has the function of the most important ecosystem in the salt marsh. However, in recent years, Cyperaceae plant communities by reclamation, pollution and other threats of biological invasion, the distribution area plummeted. Different from the past, on a large scale of salt marsh plant research with mechanism, based on the research of controlled experiments on the pot, on a small scale in Chongming East South Beach environmental factors correlation and spatial relationship of Cyperaceae and environmental factors were investigated, and explore the Chongming Dongtan wetland edge species distribution patterns and interspecific competition. For the effect, to further deepen the understanding of mechanism of plant tissue. The main results of this study are as follows: (1) the southern Chongming Dongtan unity sand space-time variation of environmental factors, habitat heterogeneity degree is high. The isotropic model, the water content and nitrate nitrogen has a strong spatial autocorrelation, and the conductivity with moderate spatial autocorrelation, bulk density and ammonium nitrogen spatial autocorrelation is very weak. The anisotropic model under various environment factors nugget. Base station values are the same, but the water content, conductivity, ammonium nitrogen and nitrate nitrogen in the range of large differences in density range of moisture was minimum. In May and November was significantly higher than that in July (one-way ANOVA, P0.05); electrical conductivity and nitrate has significant seasonal difference (one-way ANOVA, P0.0S), the highest in November, lowest in July; in May the bulk density was significantly higher than that in July and November (one-way ANOVA, P0.05); ammonium nitrogen significantly in July In May and November (one-way ANOVA, P0.05); the total inorganic nitrogen in November was significantly higher than that in May and July (one-way ANOVA, P0.05). Scirpus grass distributed in cloudy sky suitable soil moisture and high density and low conductivity of the habitat, cloudy sky grass in the higher soil moisture content, the advantage of low conductivity and density is low habitats, brown leaves of Carex suitable distributed in soil with high conductivity, low water content, ammonia nitrogen concentration was low (2). The habitat of clonal plants at different growth stages, the population density changing, the intraspecific competition intensity change, therefore, the plant will take corresponding strategies for growth and the adjustment method. The growth of Ji Zhong, Scirpus scaberrimus Carex grass and cloudy sky at different initial planting density under the growth density had significant difference (repeated measurement, ANOVA, P0.01). During the harvest, rough leaves of Carex in population under high density treatment The density was significantly higher than that of low density (one-way ANOVA, P0.05), medium density under the canopy height was significantly higher than that of low and high density treatment (one-way ANOVA, P0.05). The biomass was negatively correlated with the density of cloudy sky grass and bulrush cloudy sky grass (R2=0.541, P0.05; R2=0.520, P0.05), positively total biomass and density of grass and sedge of the cloudy sky scaberrimus (R2=0.525, P0.05; R2=0.508, P0.05), root shoot ratio were not significantly changed. Along with the density of three species of Cyperaceae family in high densities were competitive, competitive strength and high density treatments were significantly higher than those in density treatment (one-way ANOVA, P0.05). (3) the Cyperaceae plants sprout on seedling has significant competitive inhibition, but also by the inhibition of seedling seedling. In the whole growth Ji Zhong, Scirpus grass seedlings in the cloudy sky and cloudy sky and a grass sprout height of Citrullus Growth has significant difference (repeated measurementANOVA, P0.05), while no significant difference of sprouts mixed with rough leaves and grass sedge Scirpus Scirpus. When cloudy sky is cloudy sky grass seedlings Yudai grass sprout mixed, in the growing season in the late lower density than single species, but the difference was not significant; and the initiation of Carex scaberrimus hybrid seedlings, in the whole growth season sea grass seedling density Sanleng cloudy sky was lower than that of a single, very significant difference between the two (repeated measurement, ANOVA, P0.01). The cloudy sky grass, rough leaf sedge Scirpus grass sprout and cloudy sky in single and mixture under the treatment of high growth was no significant difference of interaction time and the competition has a significant effect on seedling height growth of Carex scaberrimus initiation (repeated measurementANOVA, P0.01). The initiation of three species seedlings in single and mixture density under the treatment of growth has significantly higher (repeated measurement, ANOVA, P0.01). At the end of the growing season of harvest, the competition of seedling and seedling of Scirpus grass sprout grass makes the cloudy sky cloudy sky on the ground biomass was significantly reduced (one-way ANOVA, P0.05), and the effect of the seedling initiation competition cloudy sky grass significantly reduced the bulrush seedling height and the highest cloudy sky grass canopy height seedlings (one-way ANOVA P0.05) Scirpus. Grass seedling competition effect of cloudy sky seedlings significantly reduced the maximum height of Carex scaberrimus initiation seedlings, density and aboveground biomass (one-way, ANOVA, P0.05) and Scirpus grass seedlings cloudy sky density and aboveground biomass were also significantly inhibit the initiation of Carex scaberrimus seedlings (one-way ANOVA, P0.05). Cyperaceae seedlings between seedlings and sprout a competitive relationship between the strong, and this competition is asymmetric, sprout - Scirpus grass seedlings were cloudy sky in rough leaves of Carex, sprout by competition effect was significantly higher than that of seedlings (one-way ANOVA, P 0.05). (4) has an important influence on the distribution pattern of environmental factors in the small scale of patchiness and heterogeneity of salt marsh plants, and plant species, interspecific interactions directly affect plant growth and reproduction performance. Therefore, the protection and repair of Cyperaceae plant communities, we only comprehensively considering various factors to the growth performance of Cyperaceae plant breeding, in order to more accurately understand the composition of the plant community structure and dynamic changes, provide the basis for the protection and repair of the salt marsh.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948.1

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