Effects of Grazing and Mowing on Grassland Soils, Plants and

发布时间：2022-12-08 01:52

　　理解自然界中生物群落的形成与构建机制是生态学研究的核心问题之一。当前,研究者对于人类活动干扰如何影响生物群落构建以及其内在各功能组分的化学计量学特征仍所知甚少。在全球范围内,家畜的放牧活动与割草是草地生态系统主要的两种人为管理方式。这些人类活动可以对草地系统的土壤理化性质、植被与昆虫的群落结构与组成,以及三者的碳（C）,氮（N）和磷（P）含量及其化学计量学特征产生深远影响。在过去几十年,大量的研究对放牧与割草对草地生态系统土壤、植物和昆虫群落进行了单独的研究。然而,很少研究同时比较两种管理方式对土壤、植物和昆虫等不同生物与非生物组成特征的影响,尤其是在同一个草地生态系统中。这些研究不足,一方面极大地限制了对自然草地生物群落构建方式与机制的理解,另一方面不利于相关决策部门制定合理科学的草地管理措施。在我国东北的松嫩草地,本研究通过一个为期4年的野外原位控制实验,开展中等强度的家畜放牧（牛）与人工割草如何影响草地生态系统土壤、植物和昆虫群落特征的比较研究。一方面比较了放牧与割草对草地土壤理化性质,植物与昆虫群落结构与组成等特征的影响;另一方面,比较了放牧与割草如何影响土壤、优势种植物（羊草... 

【文章页数】：111 页

【学位级别】：博士

【文章目录】：
abstract
中文摘要
Chapter1:Introduction
    1.1 Background and research progresses
        1.1.1 General features of grasslands
        1.1.2 Utilization of grazing and mowing
        1.1.3 Livestock grazing and soil properties in grasslands
        1.1.4 Livestock grazing and plant community in grasslands
        1.1.5 Livestock grazing and insect community in grasslands
        1.1.6 Mowing and soil properties in grasslands
        1.1.7 Mowing and plant community in grasslands
        1.1.8 Mowing and insect community in grasslands
        1.1.9 Trophic cascades in grasslands
    1.2 Ecological stoichiometry
    1.3 Ecological stoichiometric linkages among trophic levels
    1.4 Justification
    1.5 Aims and scope of the study
Chapter2:Materials and methods
    2.1 Study area
        2.1.1 Geographical overview
        2.1.2 Experimental site
    2.2 Experimental design and treatment
    2.3 Soil sampling and measurement
    2.4 Plant and litter sampling
    2.5 Insect sampling and measurement
    2.6 Chemical analyses for insect total C,N and P
    2.7 Insect feeding behavior
    2.8 Statistical analyses
Chapter3:Effects of grazing and mowing on soil Physiochemical properties
    3.1 Introduction
    3.2 Materials and methods
    3.3 Results
        3.3.1 Grazing/mowing and soil physical properties
        3.3.2 Grazing/mowing and soil chemical properties
        3.3.3 Relationships among soil nutrients and their ratios
    3.4 Discussion
        3.4.1 Effects of grazing and mowing on soil physical properties
        3.4.2 Effects of grazing and mowing on soil stoichiometry
        3.4.3 Effects of grazing ang mowing on soil C:N:P ratios and their relationship
    3.5 Conclusions
Chapter4:Effects of grazing and mowing on plant community diversity and productivity
    4.1 Introduction
    4.2 Materials and methods
    4.3 Results
        4.3.1 Grazing/mowing and plant community diversity
        4.3.2 Grazing/mowing and shoot,root and total biomass
        4.3.3 Grazing/mowing and ratios among shoot,root and total biomass
        4.3.4 Grazing/mowing and grasses and forbs biomass
        4.3.5 Grazing/mowing and ratios among grass,forb and shoot biomass
        4.3.6 Grazing/mowing and litter biomass
        4.3.7 Relationships between plant species evenness and shoot,root,and shoot biomass
        4.3.8 Relationships between plant species richness and shoot,root,and shoot biomass
        4.3.9 Grazing/mowing and grass,forb,and total density
        4.3.10 Grazing/mowing and ratios among grass,forb and total density
        4.3.11 Grazing/mowing and mean,grass and forb height
    4.4 Discussion
        4.4.1 Effects of grazing and mowing on plant community diversity
        4.4.2 Effects of grazing and mowing on plant community productivity
        4.4.3 Relationship between biomass and diversity
        4.4.4 Effect of grazing and mowing on plant community composition
    4.5 Conclusions
Chapter5:Effects of grazing and mowing on insect diversity and abundance
    5.1 Introduction
    5.2 Materials and methods
    5.3 Results
        5.3.1 Grazing/mowing and total insect diversity
        5.3.2 Grazing/mowing and total insect abundance
        5.3.3 Grazing/mowing and insect abundance of different trophic groups
        5.3.4 Relationships between plant species evenness and insect diversity
        5.3.5 Relationships between plant species richness and insect diversity
        5.3.6 Relationships between plant biomass and total insect abundance
        5.3.7 Relationship between plant biomass and herbivore insect abundance
    5.4 Discussion
        5.4.1 Effects of grazing and mowing on insect diversity
        5.4.2 Effects of grazing and mowing on insect community composition
        5.4.3 Relationship among plant,insect diversity and abundance
    5.5 Conclusions
Chapter6:Effect of grazing and mowing on ecological stoichiometric linkages amongtrophic levels
    6.1 Introduction
    6.2 Materials and methods
    6.3 Results
        6.3.1 Grazing/mowing and soil nutrients concentration and C:N:P stoichiometry
        6.3.2 Grazing/mowing and plant nutrients concentration and C:N:P stoichiometry
        6.3.3 Grazing/mowing and insect nutrients concentration and C:N:P stoichiometry
        6.3.4 Grazing/mowing and insect feeding behavior
    6.4 Discussion
        6.4.1 Effects of grazing and mowing on soil and plant stoichiometry
        6.4.2 Stoichiometric characteristic response to insect abundance and feeding behavior
    6.5 Conclusions
Chapter:7 General conclusions
    7.1 Main conclusions
    7.2 Suggestions for further research and management implications
References
Acknowledgements
List of publications



本文编号：3713306