呼伦贝尔草原群落根系分布构型多样化分异规律研究

发布时间：2018-04-30 07:37

本文选题：呼伦贝尔草原 + 根系分层分布构型　；参考：《内蒙古大学》2015年硕士论文

【摘要】：草地植物生物量在草地生态系统的营养物质分配和碳循环方面具有重要地位,对草地生态系统结构与功能也具有十分重要的影响。目前,对草原根系的研究大多集中在物种根系形态特征,生理特征以及根系构型等,对于草地根系地下生物量的空间分布研究也仅限于对某一具体植物类型根系整体的结构特点,而对草原区分布的各种不同草原群落及其退化类型根系生物量的系统对比研究尚未见报导。基于以上原因,本文在鄂温克旗和陈巴尔虎旗对呼伦贝尔草原开展了大量的地上生物量调查与根系分层取样测定工作,判断其地上、地下生物量的相互关系,确定群落根系的分层构型类型,同时分析了群落根系构型与植物主要类群组成的相互关系,研究了不同草地利用方式及草原退化状态对群落根系分布的影响,探讨了根系生物量对草原生态系统碳库的贡献。主要研究结论如下：1.地上生物量与每一土层深度及0-30cm、0-100cm根系生物量均具有显著的相关关系,0-30cm和0-100cm土层深度地上、地下生物量的线性回归方程可以表示为：y=5.853x+237.8 (R2=0.434; P0.001) y=6.548x+362.5 (R2=0.498; P=0.002)2.在以每个样方根系单独取样统计情况下,群落根系的分层分布具有多样化的分布构型,包括V型分布、Y型分布、E型分布、T型分布和L型分布、O型分布及X型分布。其中,前4种根系分布构型根系生物量与地上生物量具有正相关关系,而3种分布构型则表现出负相关关系。该结果是对原有对根系分层分布主要为T型分布的主要补充。3.草原植物根系分布类型与构成群落的植物类群组成存在密切联系。主要群落类型分层平均根系生物量的分布构型主要表现为V型分布、Y型分布、T型分布和L型分布4种类型。其中,V型分布和Y型分布以高大丛生禾草和杂类草植物为主,而L型分布以根茎禾草为主,小禾草比重提高,T型分布中根茎苔草占有显著优势。4.草原不同退化状态具有不同的根系分布构型。禁牧原生群落和严重退化群落表现为T型分布,但前者以原生群落建群种和杂类草植物为主,而后者以重度退化群落建群种占据绝对优势。在V型分布和L型分布中,原生群落建群种和杂类草植物占优比例相当,Y型分布中虽然仍以原生群落建群种为主,但重度退化群落建群种比例明显提高。5.不同的草地利用方式对个根系构型的根冠比有着一定程度的影响6.对不同草原类型碳库水平的分析表明,不同根系构型对应的草原生态系统碳密度存在明显差异,其变化与各种构型的退化状态具有较好的一致性。
[Abstract]:Grassland plant biomass plays an important role in the distribution and carbon cycle of the grassland ecosystem, and has a very important influence on the structure and function of grassland ecosystem. At present, the research on the root system of grassland is mostly concentrated on the morphological characteristics, physiological characteristics and root system configuration of the root system for the grasslands root system. The study on the spatial distribution of biomass is also limited to the overall structural characteristics of the root system of a specific plant type, but the systematic comparison of the root biomass of various steppe communities and their degraded types in the grassland area has not been reported. Based on the above reasons, this paper is carried out in Ewenke and Chen Banhu flag to Hulun Buir Grassland. A large number of aboveground biomass surveys and root stratified sampling are used to determine the relationship between ground and underground biomass, to determine the type of stratified configuration of the community root system, and to analyze the relationship between the structure of the community root system and the composition of the main groups of plants, and to study the use of different grassland and the degradation state of the grassland to the community root system. The contribution of the root biomass to the carbon pool of the grassland ecosystem is discussed. The main conclusions are as follows: 1. the aboveground biomass has a significant correlation with the depth of each soil layer and the root biomass of 0-30cm and 0-100cm, and the depth of 0-30cm and 0-100cm soil layer, the linear regression equation of the underground biomass can be expressed as y=5.8 53x+237.8 (R2=0.434; P0.001) y=6.548x+362.5 (R2=0.498; P=0.002) 2. has a diversified distribution configuration in the single sampling of each sample root system, which includes the distribution of V type, Y distribution, E distribution, T distribution and L distribution, O type distribution and distribution type. Among them, the first 4 root systems are distributed in the configuration roots. There is a positive correlation between the biomass and the aboveground biomass, while the 3 distribution patterns show a negative correlation. The result is the main supplement to the original T distribution of the root stratified distribution of the root system. There is a close relationship between the root distribution types of the.3. grassland plant and the composition of the plant groups in the community. The distribution patterns of biomass are mainly V type, Y type, T type and L type. Among them, the distribution of V type and Y type is dominated by tall grasses and heterozygous plants, while the L type is dominated by rhizome grasses and the proportion of small grasses increases, and the rhizomatous grass occupies a significant advantage in the different degraded state of.4. grassland in T distribution. There were different root distribution configurations. The primary and severe degraded communities were T type, but the former was dominated by primary and heterozygous plants, while the latter was dominant in the severe degraded communities. In the distribution of V and L, the proportion of the original group of Rogaine and the hetero grass was equal, Y Although the primary community was still the dominant species in the type distribution, the proportion of the plant species in the severe degraded communities was obviously increased by the different grassland utilization methods of.5., which had a certain influence on the root and crown ratio of the root system. The analysis of the carbon pool level of different grassland types showed that the carbon density of the grassland ecosystem corresponding to the different root system configurations existed in different root systems. Obviously, the change is in good agreement with the degradation state of various configurations.

【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S812

【参考文献】