长白山阔叶红松林演替系列主要树种叶片功能性状与化学计量学研究

发布时间：2018-03-21 14:56

本文选题：森林演替　切入点：功能性状　出处：《中国林业科学研究院》2017年博士论文　论文类型：学位论文

【摘要】：演替能显著改变森林群落结构和生态系统功能,叶片功能性状和生态化学计量学分别将叶片性状和元素平衡关系与生态过程联系起来。长白山自然保护区拥有完整的原始阔叶红松林生态系统,并与周边分布的不同林龄的杨桦次生林,共同形成了从先锋到顶级群落的次生演替系列。本论文研究了长白山阔叶红松林演替过程中主要树种的叶片功能性状和生态化学计量学的变异性,为深入理解森林演替过程中群落结构和生态系统功能的动态及其机制提供新的见解。本文主要研究结果如下:1.基于11个20 m×20 m不同林龄的样地数据,发现随着阔叶红松林演替系列的进行,群落乔木组成和树种多样性发生明显的变化,而乔木生物量从10年生(16.0-32.5 t ha-1)、30年生(171.1-206.7 t ha-1)、70年生(226.2-285.2 t ha-1)杨桦林向200年生(328.3-514.2 t ha-1)阔叶红松林持续增加。有趣的是,不耐阴的水曲柳(最大寿命280年)和一般耐阴的蒙古栎(最大寿命270年)在演替前期和后期都占据一定优势地位,而不耐阴的白桦和山杨(最大寿命均为150年)在演替后期被淘汰,说明物种的替代是耐阴性和寿命共同变化的结果。2.对于自然生境下不同演替阶段6个主要树种的小树和大树,方差分析和主成分分析共同表明,在所分析的13个叶片功能性状中,不耐阴前期树种与耐阴后期树种的主要差异不是光合能力(饱和光强下的光合速率)或光合潜力(最大羧化速率和电子传递速率),而是比叶重(LMA)。然而,这种差异仅在光照条件不同的小树阶段表现明显,而当前期和后期树种都发育成为冠层大树之后,这种差异消失甚至发生逆转。3.所有树种的单位质量叶片光合能力(Amass)都随个体发育而下降,即使林下遮光后期种小树Amass也比林冠大树高。但不耐阴前期树种单位面积叶片光合能力(Aarea)随个体发育下降,而耐阴后期种Aarea随个体发育增加。进一步定量分析表明,在个体发育过程中,前期树种主要通过改变叶片内部N分配和光合N利用效率来调整光合能力,而后期树种主要通过改变叶片结构(即LMA)来优化光合表现。4.顶级树种红松是一种常绿针叶树种,树冠由不同年龄的叶片组成。结果表明,红松小树Amass和气孔导度(gs)均高于大树,与大树更受水力限制的假说一致。此外,通过对比当年生和1年生叶片的功能性状,发现林下遮阴小树叶片LMA和光合生理性状比冠层大树更易受叶龄的影响,这可能是由于林下光照限制了叶片生长导致的。5.不同演替阶段7个树种叶片碳(C)、氮(N)含量和C:N比在森林发育过程中保持稳定;而除了山杨外,其他树种枝条或细根C、N含量和C:N比变化显著。这意味着叶片C:N化学计量稳定性高于枝条和细根。群落水平上叶片C:N比在林龄70年生以下的杨桦林保持稳定,而在200年生阔叶红松林显著增加,说明演替顶级群落拥有更高的N利用效率。表层土壤(0-10cm)C含量与N含量等速变化,因而土壤C-N之间保持耦合,但植物器官和凋落物不存在这种C-N耦合关系。
[Abstract]:Succession can significantly change the forest community structure and ecosystem function, leaf functional traits and ecological stoichiometry were linked to leaf traits and balance the relationship between elements and ecological processes. The Changbai Mountain Nature Reserve has original broad-leaved forest ecosystem, and with different ages surrounding the distribution of secondary poplar birch forest, formed from pioneer to secondary succession climax. This paper studied the variability of leaf functional traits and ecological stoichiometry of main tree species of broadleaved Korean pine forest in Changbai Mountain in succession, provide new insights into the dynamic mechanism and its deep science community structure and ecological system in forest succession function. The main results of this paper are as follows: 1. based on 11 20 m * 20 m different age of the sample data, found with the broad-leaved Korean pine forest succession, community composition and tree Tree species diversity changed obviously, and the tree biomass from 10 years old (16.0-32.5 t HA-1), 30 years (171.1-206.7 t HA-1), 70 year old Yang Hualin (226.2-285.2 t HA-1) to 200 years (328.3-514.2 t HA-1) in broad-leaved Korean pine forest continued to increase. Interestingly, no shade of water ash (maximum life span of 280 years) and the shade of the oak in Mongolia (the maximum life span of 270 years) will occupy a certain advantage in the early and late succession, without shade of birch and poplar (maximum life span is 150 years) was eliminated in the late successional species, that alternative is resistant to negative and common life changes the results of.2. for the 6 main tree species in natural habitats in different successional stages of trees and trees, variance analysis and principal component analysis show that in the 13 leaf functional traits analysis, shade intolerant species and shade tolerant species in the late stage of the main difference is not photosynthetic capacity (full The photosynthetic rate and light intensity) or photosynthetic potential (maximum rate of carboxylation and electron transfer rate), but the specific leaf weight (LMA). However, the difference only in the performance of young trees of different illumination significantly, and when the early and late species have developed into canopy trees, leaves the unit mass the differences disappear or even reverse.3. of all species of photosynthetic capacity (Amass) decreased with the development of individuals, even under the forest trees for Amass than the late shading canopy trees. Not resistant to leaf Yin early successional tree species photosynthetic capacity per unit area (Aarea) with individual development and decline, the shade of late Aarea with individual the development of further increased. The quantitative analysis showed that during ontogeny, early successional tree species mainly by changing the internal N distribution and leaf photosynthetic N use efficiency to adjust the photosynthetic capacity, while the latter species mainly by changing the structure of leaves (LMA). Optimization of photosynthetic performance of.4. top species of Korean pine is an evergreen conifer, a crown of leaves of different age. The results show that the pine tree Amass and stomatal conductance (GS) were higher than that of trees, the more favorable the hydraulic limitation hypothesis and trees. In addition, by comparing the year and 1 year old leaf functional traits influence of forest shade, small leaf LMA and photosynthetic physiological traits are more susceptible than leaf canopy trees, which may be due to the limitation of understory light leaves led to the growth of.5. in different successional stages of 7 species of leaf carbon (C), nitrogen (N) content and C:N ratio remained stable in the forest development process; in addition to Aspen, other tree branches or root C, N content and C:N ratio changes significantly. This means that the leaf C:N stoichiometry stability is higher than the level of community branches and fine root. Leaf C:N ratios remained stable in the age of 70 years under Yang Hualin, and The 200 year old broad-leaved Korean pine forest increased significantly, indicating that the successional climax community had higher N utilization efficiency. The surface soil (0-10cm) C content and N content changed at the same speed, so the soil C-N remained coupled, but there was no C-N coupling relationship between plant organs and litter.

【学位授予单位】：中国林业科学研究院
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S718.5

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