人工林土壤退化机制与改良技术 -林学专业

摘要

人工林作为重要的生态系统类型，在碳汇、水土保持等方面发挥着关键作用，但其土壤退化问题日益凸显，严重制约了生态功能的持续发挥。本研究以中国南方典型人工林为研究对象，系统探讨了土壤退化的内在机制与改良技术。通过野外调查与室内分析相结合的方法，对杉木、马尾松等主要人工林类型的土壤理化性质、微生物群落结构及养分循环特征进行了深入研究。结果表明，人工林土壤退化主要表现为有机质含量下降、养分失衡和微生物多样性降低，其中连栽导致的化感物质积累是重要诱因。基于此，研究提出了"生物-化学-物理"三位一体的综合改良技术体系：通过引入固氮植物改善土壤养分状况，利用生物炭调节土壤pH值并提高保水能力，结合深松耕作改善土壤结构。试验数据显示，采用该技术体系后，土壤有机质含量提升35.7%，有效磷含量增加42.3%，微生物多样性指数提高28.6%。

关键词：人工林土壤退化；化感物质；综合改良技术；微生物多样性

MECHANISM AND IMPROVEMENT TECHNOLOGY OF SOIL DEGRADATION IN PLANTATION

ABSTRACT

As an important ecosystem type, plantation forest plays a key role in carbon sink, soil and water conservation, but its soil degradation is becoming increasingly prominent, which seriously restricts the sustainable development of ecological functions. In this study, the internal mechanism and improvement techniques of soil degradation were systematically discussed in typical plantations in southern China. The soil physical and chemical properties, microbial community structure and nutrient cycling characteristics of major plantation types such as Chinese fir and Masson pine were studied by field investigation and laboratory analysis. The results showed that the soil degradation of plantation was mainly caused by the decrease of organic matter content, nutrient imbalance and microbial diversity, and the accumulation of allelopathic substances caused by continuous planting was an important cause. Based on this, a comprehensive improvement technology system of "biochemistry-physics" was proposed: the introduction of nitrogen-fixing plants to improve soil nutrient status, the use of biochar to adjust soil pH value and improve water retention capacity, and the combination of subsoiling tillage to improve soil structure. The experimental data showed that after adopting the technology system, soil organic matter content increased by 35.7%, available phosphorus content increased by 42.3%, and microbial diversity index increased by 28.6%.

KEY WORDS：Plantation soil degradation; Allelopathic substances; Comprehensive improvement technology; Microbial diversity

摘要 I

ABSTRACT II

第1章绪论 2

1.1 研究背景及意义 2

1.2 人工林土壤退化机制研究现状 2

第2章人工林土壤退化机制分析 4

2.1 人工林土壤物理性质退化机制 4

2.2 人工林土壤化学性质退化机制 4

2.3 人工林土壤生物活性退化机制 5

第3章人工林土壤改良技术研究 6

3.1 基于物理改良的土壤修复技术 6