浙东森林群落木本植物的形态和功能型谱

发布时间：2018-06-26 03:18

本文选题：树木构型 + 群落垂直结构　；参考：《华东师范大学》2017年硕士论文

【摘要】：构型配置是植物对环境的形态外貌适应。大量研究表明,随着水热和光线环境的变化,植物会表现出不同的构型策略,从而形成全球尺度上的植物形态和功能型谱。在局域森林群落中,处于不同垂直层次的树木也具有构型配置模式的差异,其中,光资源获取和水分运输特征可能是引起这种变化的主要驱动因素。但是,当前缺乏对这一群落形态和构型配置现象的生理学解释,因而无法检验是否在群落尺度上也存在树木的形态和功能型谱。本研究以浙江天童木荷群落(2个20×20 m2)和普陀山枫香群落(2个20×20m2)为研究对象,测定了样地内每木个体的构型性状(株高、树冠面积、树冠厚度、水平枝比例、垂直枝比例等)、光线利用性状(最大光合速率、光饱和点、光补偿点、气孔密度等)、水分利用性状(导管直径、干材密度、导水率、边材比导率、蒸腾速率等)、叶经济性状(比叶面积、叶氮含量、叶干物质含量),以及树干温度。首先采用线性模型分析了株高和其它构型性状之间的关系;其次,运用结构方程模型探索光线利用性状和水分利用性状对株高的影响程度,并验证枝叶空间搭配方式是否是树木对光水利用性状的一种补偿机制,从而间接影响株高;最后,采用主成分分析,综合揭示了水分运输和利用性状、光线利用性状、叶经济性状、树干日温差及构型性状之间的相互关系,建立了群落尺度的树木形态结构与功能型谱。主要结果如下:(1)两类群落植物构型特征随垂直层梯度的变化出现显著分化。垂直枝比例、树冠面积、树冠厚度以及木质部导管直径均随着株高的增大而增大,而0级和1级枝数量随株高的增大而减少(p0.05)。该结果说明株高越高,植物的空间体积越大,外貌特征结构更为紧凑,但解剖构型更为疏松。此外,木荷群落中株高较大的个体配置有更长的叶柄长度及直径、更大的单叶面积,并且当年生叶片数较多,说明这些性状的特征有利于植物垂直高度的生长。(2)结构方程分析表明,光线利用性状和水分利用性状均对株高产生显著影响。其中,光饱和点、光补偿点、导管直径、叶干物质含量、蒸腾速率以及液流通量对株高有显著正影响(p0.05)。其次,植物可以通过构型的调整而补偿植物水分运输性状以及光线利用性状的投入消耗,当垂直枝比例较大、叶片聚集分布以及当年生叶片较少时,可以确保植物具有较大的蒸腾拉力和导管直径,并且对光资源的利用较为充分,从而有利于水分运输到较大高度以及具备较强的光合作用,有利于株高的生长。相反地,水平枝较多、叶片分散分布以及当年生叶片较多时,水分运输阻力较大,而蒸腾合力较小,并且对光线利用能力较弱,从而不利于植物生长到较大高度。(3)综合考虑光线利用性状和水分利用性状对株高的影响,两类群落树木高度的生理学机制存在差异。木荷群落光线利用性状对株高影响的效应大于水分利用性状,而枫香群落表现出相反的趋势,说明木荷群落株高主要受光资源的限制,而枫香群落植物高度主要受水资源的限制。(4)基于两种群落类型构建的形态与功能型谱,存在以株高、叶片分散度、水平枝比例为主的形态与功能型谱,代表了植物构型对温度变幅以及光水利用的一种补偿机制。在树干日温差-株高这一维度的功能型谱中,树干日温差变化较小的个体集中分布于株高较大的一端,但树干日温差变化较大的个体集中分布于株高较矮的一端。在木荷群落中,主要存在液流通量-光饱和点-最大光合速率-叶片分散度和叶氮含量-气孔导度-水平枝比例这两个维度上的植物形态与功能型谱,表征植物水分运输和光合作用强的性状集中于叶片聚集分布以及垂直枝比例大的一端,而表征水分运输和光合作用弱的性状集中于叶片分散分布以及水平枝比例大的一端;而在枫香群落中,基于叶片分散度和水平枝比例这两个维度上,仅存在围绕构型为主的植物水分利用能力的功能型谱。(5)综合两类群落整株植物的经济型谱,在局域尺度范围内不存在叶经济型谱,但存在以株高为主的"保守策略"与"奢侈策略"的功能型谱。奢侈型植物具有大的株高、树冠和较强的光线利用和水分利用能力;反之,保守型植物株高和树冠较小,具有较弱的光线利用和水分利用能力。此外,还存在四个维度的植物形态与功能型谱,即:叶片水势-叶柄胡伯尔值-叶比导率(叶片水力经济型谱)、导水率-气孔导度-叶片分散度(基于叶片分散度的碳水耦合功能型谱)、叶氮含量-枝条胡伯尔值-叶干物质含量-水平枝比例(基于水平枝比例的碳水耦合功能型谱)以及叶柄胡伯尔值-干材密度(基于干材密度的水分利用功能型谱)。(6)不同生活型群落以及不同高度层植物,分别沿着叶片水力经济型谱以及株高经济型谱出现明显分化,常绿木荷群落相对落叶枫香群落植物叶片具有更大的水分利用能力,高个体植物倾向于"奢侈型策略"的一端,而矮个体出现在"保守型策略"的一端。综上,本研究通过对两种群落类型的光线利用性状和水分利用性状与基于垂直层次构型性状之间关系的研究,在分析群落垂直层层片配置变化特征的基础上,证明了树木构型是对水分和光线利用能力的一种补偿策略,从光水利用特征功能性状的角度揭示了浙东森林群落植物垂直梯度株高变化的生理学机制,建立了基于植物高度为主的局域群落树木形态结构与功能型谱,为深入理解群落植物构型配置提供了研究依据。
[Abstract]:Configuration configuration is the morphological adaptation of plants to the environment. A large number of studies have shown that with the change of water heat and light environment, plants show different configuration strategies, thus forming plant morphology and functional profiles on the global scale. In local forest communities, trees at different vertical levels also have the difference in configuration pattern. Differences, among them, the acquisition of light resources and the characteristics of water transport may be the main driving factors that cause this change. However, there is a lack of physiological interpretation of the morphology and configuration of this community, so it is impossible to test whether there is a tree's morphological and functional profile on the scale of the community. In this study, the Zhejiang Tiantong Schima superba community (2 20 x 20 m2) and Mount Putuo Fengxiang community (2 20 x 20m2) were used to determine the configuration traits of individual wood in the sample (plant height, crown area, crown thickness, horizontal branch ratio, vertical branch ratio, etc.), light utilization traits (maximum photosynthetic rate, light saturation point, light compensation point, stomatal density, etc.), water use traits (diameter of ducts, dry wood) Density, water conductivity, sapwood specific conductivity, transpiration rate, leaf economic traits (specific leaf area, leaf nitrogen content, leaf dry matter content), and trunk temperature. First, the linear model was used to analyze the relationship between plant height and other configuration traits. Secondly, the structure square model was used to explore the effect of light utilization and water utilization on plant height. The degree of ringing, and verifying whether the spatial collocation of branches and leaves is a compensatory mechanism for trees on the use of light water, indirectly affects plant height. Finally, the principal component analysis is used to comprehensively reveal the relationship between water transport and utilization traits, light utilization traits, leaf economic characters, dry day temperature difference and configuration characters. The main results were as follows: (1) the characteristics of plant configuration in the two groups were significantly differentiated with the gradient of vertical layers. The ratio of vertical branches, crown area, crown thickness and xylem diameter increased with the increase of plant height, while the number of 0 and 1 branches decreased with the increase of plant height (P0 .05). The results indicate that the higher the height of the plant, the larger the space volume, the more compact structure of the appearance, and the more loose anatomical structure. In addition, the larger individual plants in the lotus community have longer petiole length and diameter, larger single leaf area, and more leaves in the same year, indicating that the characteristics of these traits are beneficial to the plants. The growth of vertical height. (2) structural equation analysis showed that both light utilization and water use traits had significant effect on plant height, of which light saturation point, light compensation point, catheter diameter, leaf dry matter content, transpiration rate and liquid flux have significant positive effect on plant height (P0.05). Secondly, plants can be compensated by the adjustment of configuration. When the plant water transport characteristics and the input consumption of light use characteristics, when the vertical branch ratio is larger, the leaf aggregation distribution and the leaf blade are less, it can ensure that the plant has greater transpiration and catheter diameter, and the use of light resources is more sufficient, thus it is beneficial to the transport of water to a greater height and is stronger. Photosynthesis is beneficial to the growth of plant height. On the contrary, when the horizontal branches are more, the leaves are distributed and the leaves are large, the water transport resistance is larger, and the transpiration is less, and the use of light is weak, which is unfavorable to the plant growth to a greater height. (3) comprehensive consideration of the use of light and water use traits. The effect of plant height, the physiological mechanism of tree height in the two types of community is different. The effect of light utilization on plant height is greater than that of water use, while the maple community shows the opposite trend, which indicates that the height of plant height is mainly restricted by light resources, and the height of the plant is mainly restricted by the water resources. (4 Based on the morphological and functional profiles constructed by two types of community types, the morphological and functional profiles of plant height, leaf dispersity and horizontal branch ratio mainly represent a compensatory mechanism for the temperature variation and the use of light water in plant configuration. In the functional spectrum of the day temperature difference to the height of the plant height, the variation of the temperature difference of the tree trunk is smaller. The body concentrates on the high end of plant height, but the individuals with larger diurnal temperature difference are concentrated on the lower end of plant height. In the lotus community, there are mainly plant morphology and functional profiles on the two dimensions of liquid flux - light saturation point - maximum photosynthetic rate - leaf dispersity and leaf nitrogen content - stomatal conductance - horizontal branch ratio The characteristics of plant water transport and photosynthesis are concentrated on the leaf aggregation distribution and the large proportion of vertical branches, while the weak characteristics of water transport and photosynthesis are concentrated on the dispersal distribution of leaves and the large proportion of the horizontal branches, while in the maple community, the two dimensions of leaf dispersion and horizontal branch ratio are based. On the other hand, there are only the functional profiles of the water use ability of the plants centered around the configuration. (5) the economic profile of the whole plant of the two types of communities is integrated, and there is no leaf economic profile within the local scale, but there is a power spectrum of the "conservative strategy" and the "luxury strategy", which is dominated by plant height. Light use and water use ability; conversely, conserved plant height and crown are smaller, with weak light use and water use ability. In addition, there are four dimensions of plant morphological and functional profiles, namely, leaf water potential - leaf stalk Huber value - leaf ratio conductance (leaf hydraulic economy type), water conductivity - stomatal conductance - leaf dispersion (based on the carbon water coupling function spectrum of leaf dispersion), leaf nitrogen content - Branch Huber value - leaf dry matter content - horizontal branch ratio (based on horizontal branch ratio carbon and water coupling spectrum) and stem wood density - dry wood density (based on dry wood density based energy energy spectrum). (6) different living communities and different height layers The plants have obvious differentiation along the leaf hydraulic and plant height economic profiles. The evergreen wood lotus community has a greater water use ability than the leaves of the deciduous Maple community. The high individual plants tend to one end of the "luxury strategy", while the dwarf individuals appear at the end of the "conservative strategy". The relationship between two types of community types of light use and water use and vertical structure based on the vertical layer configuration characters. Based on the analysis of the characteristics of the vertical layer configuration changes, it is proved that the tree configuration is a compensation strategy for the use of water and light, from the angle of the use of the characteristic functional properties of the light water. The physiological mechanism of vertical gradient plant height variation in the forest community in eastern Zhejiang was shown, and the tree morphological structure and functional profile of local community based on plant height were established, which provided a basis for understanding the configuration of plant configuration in the community.
【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】：S718.5

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