吉林蛟河针阔混交林种子扩散和幼苗更新研究

发布时间：2018-03-02 00:12

本文关键词： 种子雨幼苗更新种子扩散定居限制负密度制约物种共存　出处：《北京林业大学》2016年博士论文　论文类型：学位论文

【摘要】：种子植物的天然更新主要经历种子雨、种子扩散和幼苗定植三个过程。其中,种子(种子雨或种子库)和幼苗(或幼树)阶段被认为是森林更新过程中最重要和敏感的两个时期,也是未来群落组成和结构的决定性因素。研究种子扩散和幼苗更新二者之间关联性,以及扩散限制、负密度制约效应和生态位过程在种子扩散和幼苗更新过程中的相对重要性,将有助于我们更好地解释生物多样性的形成、维持与进化机制,从而为森林生态系统生物多样性保护提供理论依据。该文以位于吉林蛟河地区的中龄林(the half-mature forest、成熟林(the mature forest:MF)和老龄林(the old growth forest:OGF)3种类型的针阔混交林监测样地为基础,每块样地代表了一个特定的演替阶段。在样地内共设置了451个种子雨-幼苗观测样站。通过连续3年的调查和观测,分析了不同演替阶段的群落中种子雨和幼苗的物种组成及其在时间和空间尺度上的变化格局。检验了局域尺度上负密度制约效应和生态位过程对幼苗存活的影响。分析和评价了扩散限制、密度制约效应和生态位过程在物种多样性维持中的作用。主要研究结果如下：1、蛟河地区不同演替阶段针阔混交林样地中种子雨具有明显的季节动态,有时会呈现双峰模式。绝大多数物种的种子产量存在着较大的年际变异和空间变异,并且空间变异系数远大于年际变异系数。然而种子的年际和空间变异并不随着演替进程的推进而变化。2、用多元回归的方法分析了幼苗数量与林分类型、同种成体胸高断面积之和以及林冠开阔度的关系。结果表明：(1)林下层主要木本植物幼苗的组成在不同演替阶段群落中差异不大,并与样地内主要树种组成保持着一定相似性,但幼苗重要值排序在年际间和不同演替阶段稍有波动。(2)3个样地内幼苗个体数量和物种数都主要集中在5-20 cm高度级之间,之后随高度级增加而逐渐减少,但幼苗个体数量减少得更快。这表明与种间竞争相比,物种内部的相互作用是导致幼苗死亡的主要原因,在一定程度上证实了负密度制约效应在幼苗更新过程中的作用。(3)水曲柳(Fraxinus mandshurica)、色木槭(Acer mono)、青楷枫(Acer tegmentosum)、东北槭(Acer mandshuricum)和紫椴(Tilia amurensis)5个主要树种的幼苗都与同种成体胸高断面积之和呈显著的正相关关系,还呈现出明显的生境偏好,表明扩散限制和生态位过程也会影响幼苗的数量和分布。间接证实了负密度制约效应、扩散限制和生态位过程对温带地区不同演替阶段森林群落中幼苗数量组成的影响。3、幼苗的空间分布对群落更新具有重要意义。对木本植物幼苗的数量分布以及水曲柳、色木槭、杉松(Abies holophylla)和东北槭4个主要树种幼苗与大树的空间关系及其年际变化进行了分析,并用Syrjala检验来分析样站尺度上,幼苗密度、丰富度的空间分布在年际间的差异。结果显示：(1)木本植物幼苗的数量分布在不同群落和年际之间都表现出明显的差异,样站尺度上3个样地内的幼苗密度存在着较大的空间变异性,而幼苗丰富度的空间异质性较低。表明幼苗分布的空间异质性对幼苗密度有着重要影响。(2)样站尺度上幼苗数量、物种数的空间分布在不同年份之间是存在差异的。在一定程度上证实了种子产量、扩散方式和群落组成对幼苗空间分布的影响。(3)从幼苗与大树空问关系来看,4个主要树种的幼苗与成树之间表现出相似的分布格局,表明成体植株的空间分布特征也能够影响幼苗的空间分布。4、对种子限制和定居限制的研究表明,温带森林中也存在着较强的种子限制,并且演替初期种子限制的强度要明显高于演替中期和后期。演替初期和中期物种的更新受限主要受种子产量不足和扩散限制影响,而在演替后期物种的更新主要受扩散限制的影响。种子限制与定居限制之间没有显著负相关关系,表明我们的研究结果并不支持拓殖-竞争权衡促进物种共存的假说。相反,扩散限制与定居限制之间的显著正相关关系,从侧面证明了负密度制约效应对本研究区域物种共存的促进作用。我们的研究并没有发现种子限制和定居限制受种子的大小调控。此外,幼苗的定植主要受到生物因素的影响。5、通过广义线性混合效应模型(generalized linear mixed-effects models, GLMMs)检验了生物和非生物邻体对幼苗存活的影响以及生物邻体对幼苗存活影响的种间差异。结果表明温带森林中存在着负密度制约效应。生物、非生物因素都会影响幼苗的存活,其相对重要性会随着演替进程、幼苗大小、幼苗年龄而变化。对于高度小于20cm、1-2年生的幼苗以及全部群落水平的幼苗来说,负密度制约的强度在物种问存在着显著差异。同时我们还发现,局域尺度的负密度制约效应并没有导致群落补偿趋势。我们的研究结果证实了负密度制约效应和生态位过程对幼苗存活的影响,并且它们的相对重要性会随着幼苗高度、年龄而变化。此外,生物和非生物因素对幼苗存活的影响会随着演替进程而变化。
[Abstract]:The natural regeneration of seed plants mainly through seed rain, seed dispersal and seedlings planting three process. Among them, the seed (seed rain or seed) and seedling stage (or tree) is considered to be the most important in the process of forest regeneration and two sensitive period, but also the future of community composition and structure of the decisive factors associated. Between the study of seed dispersal and seedling regeneration in two, and the diffusion limitation, the negative density dependent effect and the relative importance of the niche in the process of updating the seed dispersal and seedlings in the process, will help us to better explain the formation of biodiversity, maintenance and evolution mechanism, which provides a theoretical basis for forest ecosystem biodiversity the protection of the middle age forest. Located in the Jilin Jiaohe area (the Half-mature forest (the mature forest:MF) mature forest and old growth forest (the old growth forest:OGF) 3 types of quotmixed coniferquot To forest monitoring plots as the basis, each sample represents a specific stage of succession. The 451 seed rain observation stations were set in the seedling plots. Through the investigation and observation for 3 years, analyzed the seeds of different successional stages in the rain and seedling species composition and in time and the spatial scale change pattern. The test on a local scale negative density dependent effects and niche of seedling survival. Analysis and evaluation of the diffusion limitation, density effect and ecological niche in the process of species diversity in the role. The main results are as follows: 1. The seed rain in Jiaohe area at different successional stages coniferous forest plots have obvious seasonal changes, sometimes show the Shuangfeng mode. Seed yield of most species exist interannual variability and spatial variation is larger, and the spatial variability coefficient is far greater than the When the coefficient of variation. However, interannual and spatial variability of seed is not with the succession process and the changes of.2, using multivariate regression method analyze the number and type of forest seedlings, the same as the relationship between body basal area and canopy openness. The results showed that: (1) under forest layer of main woody plant seedlings the difference in the composition of communities in different successional stages in small, and maintain a certain similarity with the main tree species in the plot, but the seedlings had slight fluctuations in the value of order of the interannual and different successional stages. (2) in 3 sample plots of seedling number of individuals and species are mainly concentrated in the 5-20 cm level. When the height gradually decreases, but the decrease in the number of seedlings were faster. This shows that compared with interspecific competition, interaction within a species is the main cause of seedling death, to some extent confirms the negative density The role of restricting effect in seedling regeneration process. (3) (Fraxinus mandshurica), Fraxinus mandshurica Acer (Acer mono), Qing Kai Feng (Acer tegmentosum (Acer), northeast of Acer mandshuricum) and linden (Tilia amurensis) the 5 main species of seedlings with the same basal body showed positive correlation a significant relationship between area and habitat preference also showed obvious, showed that diffusion limitation and niche process will also influence the distribution and quantity of seedlings. Indirectly confirmed the negative density dependent effects,.3 diffusion limited and niche process on the number of seedlings of forest communities in different successional stages in temperate regions, seedlings of space the distribution of community renewal has important significance. The number and distribution of woody plant seedlings of Fraxinus mandshurica, Acer mono, Sugi Matsu (Abies holophylla) and Its Interannual and spatial relations in Northeast Acer 4 main tree species of seedlings and trees. For the analysis, and use Syrjala test to analyze the sample stand scale, seedling density, the differences in the spatial distribution of abundance between years. The results showed that: (1) the number of seedlings of woody plants distributed between different communities and interannual showed distinct differences, seedling density of 3 plots in the stand scale there are large spatial variability, and the spatial heterogeneity of seedling richness was low. Show that the spatial heterogeneity of seedling distribution have an important influence on the density of seedlings. (2) stations on the scale of seedling number, the number of species distribution space is different in different years. To some extent confirmed the seed yield, diffusion and community composition effects on seedling spatial distribution. (3) from seedling and tree spatial relations, between the 4 main species of seedlings and trees showed a similar distribution pattern, showed that the spatial distribution of adult plants The distribution characteristics of.4 can influence the spatial distribution of seedlings, of seed limitation and establishment limitation, there is a strong limit of temperate forests of seed, and the early strength was higher than that of seed limited succession succession of middle and late successional species in the early and mid update Limited mainly by seed yield insufficient and limited diffusion effect in effect, the late successional species regeneration is diffusion limited. Seed limitation is not negatively related with settled restrictions, that our results do not support the development and Competition Promoting species coexistence tradeoff hypothesis. On the contrary, diffusion between limits and restrictions settled a positive relationship from the side that negative density control effect of the study area to promote the role of species coexistence. Our study found no seed limitation and establishment limitation in seed Control. In addition, the seedling planting is mainly influenced by the biological factors of.5 by generalized linear mixed effects model (generalized linear mixed-effects models, GLMMs) to test the biological and non biological neighbor effect on seedling survival and seedling survival of neighborhood effects of biological species differences. The results show that there is a negative density dependence in temperate zone forest. Biological, non biological factors will affect seedling survival, the relative importance of the succession process, seedling size, seedling age and height changes. For less than 20cm, 1-2 year old seedlings and seedlings of all community level, the strength of the negative density dependent. There were significant differences in species. At the same time we also found that local scale negative density restriction effects did not lead to community compensation trend. Our results confirmed the negative density dependent effects and ecological process of the young Miao Cunhuo's influence and their relative importance vary with seedling height and age. In addition, the influence of biological and abiotic factors on seedling survival will change with succession process.

【学位授予单位】：北京林业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S718.5

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