紫金山土壤动物对凋落物分解的作用与机制

发布时间：2022-12-22 07:38

　　森林凋落物是重要的有机物和养分储存库。凋落物分解在维持森林生态系统生产力、土壤有机质的形成以及群落演替等方面具有不可替代的地位。随着人口增长,燃料燃烧,人类向大气中排放含氮化合物越来越多,大气氮沉降成比例增加。过量大气氮沉降引发了诸如土壤酸化、营养储存失衡等一系列严重的生态问题,同时也影响着凋落物分解过程。目前对控制凋落物分解的主要驱动因子已有广泛研究,然而这些因子在凋落物分解过程的交互作用及其对森林生态系统功能调控机制的研究较少,尤其是土壤分解者对环境变化,不同植物及凋落物质量的响应机制。因此,从土壤腐食食物链出发,研究大气氮沉降、土壤微环境以及植物次生代谢物对凋落物分解的影响,从土壤分解者群落组成和功能多样性等方面探索气候变化、凋落物质量以及土壤分解者交互作用对森林生态系统碳循环研究具有重要的理论和实践指导意义。本研究选择中国南京紫金山地区亚热带针叶林、阔叶林及针阔混交林作为实验样地。首先,我们在针叶林和阔叶林收集优势树种马尾松、栓皮栎凋落物作为实验材料。两种凋落物分别置于针叶林、阔叶林的凋落物层及土壤层进行十个月（2013.2-2013.12）的凋落物袋分解实验,我们比较了不同土... 

【文章页数】：138 页

【学位级别】：博士

【文章目录】：
摘要
Abstract
Chapter 1 Introduction
    1.1 Litter decomposition and ecological roles
    1.2 Processes of litter decomposition
    1.3 Factors driving litter decomposition
    1.4 Atmospheric nitrogen deposition
        1.4.1 Effects of N deposition on environment
        1.4.2 Effects of anthropogenic N deposition on litter decomposition
    1.5 Secondary compounds in litter decomposition
    1.6 Research objective
    1.7 Reference
Chapter 2 Succession of soil fauna communities during the litter decompositionprocesses in different vertical positions of soil
    2.1 Introduction
    2.2 Materials and methods
        2.2.1 Site description
        2.2.2 Litter collection and experimental design
        2.2.3 Mesofauna extraction and identification
        2.2.4 Soil physiochemical properties and litter decomposition
        2.2.5 Statistical analysis
    2.3 Results
        2.3.1 Litter decomposition
        2.3.2 Changes in soil mesofauna abundance and taxa richness during decomposition
        2.3.3 Changes in soil enzyme activities and respiration rate
    2.4. Discussion
Chapter 3 Effect of N addition on home-field advantage of litter decomposition insubtropical forests
    3.1 Introduction
    3.2 Methods and Materials
        3.2.1 Study site
        3.2.2 Experiment design
        3.2.3 Mesofauna extraction
        3.2.4 Chemical analysis, soil pH, soil microbial biomass, and enzyme activitydetermination
        3.2.5 Data analyses
    3.3 Results
        3.3.1 Decomposition rates and HFAI
        3.3.2 Changes in litter quality during decomposition
        3.3.3 Soil enzyme activities in N addition and control treatments
        3.3.4 Changes in soil fauna and microbes
    3.4 Discussion
        3.4.1 Litter decomposition rates and HFA in broad-leaved and coniferous forests
        3.4.2 Effects of N addition on HFA effect
Chapter 4 Secondary compounds of Pinus massoniana alter decomposers effect on litterdecomposition
    4.1 Introduction
    4.2 Materials and Methods
        4.2.1 Collection of soil, leaf litter, and isopods
        4.2.2 Aqueous extract of P. massoniana litter and tannins extract experiment
        4.2.3 Collection of isopods
        4.2.4 Laboratory experiment design
        4.2.5 Chemical analysis, soil pH, soil microbial respiration, and enzyme activitydetermination
        4.2.6 Data analyses
    4.3 Results
        4.3.1 Litter decomposition rate
        4.3.2 Soil carbon and nitrogen content and pH
        4.3.3 Soil microbial biomass
        4.3.4 Soil extracellular enzymes
    4. 4 Discussion
        4.4.1 Effect of aqueous extracts on litter decomposition
        4.4.2 Effect of tannins on litter decomposition
        4.4.3 Effect of aqueous extracts and tannins on soil extracellular enzymes
Chapter 5 Summary
    5.1 Conclusions
    5.2 Prospects
Reference
List of publications
Acknowledgements
Appendix A
Appendix B



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