人工林土壤有机质分解速率与温度关系研究 -林学专业

摘要

人工林土壤有机质分解是生态系统碳循环的重要环节，其速率受温度等环境因素的显著影响。近年来，随着全球气候变暖，人工林土壤有机质的分解过程及其对温度的响应机制成为研究热点。本研究旨在探讨不同温度条件下人工林土壤有机质分解速率的变化规律，并揭示其内在机制。通过在中国东北地区选取典型人工林进行野外实验，结合室内培养实验，采用静态箱法和酶动力学分析技术，系统研究了温度在5℃至40℃范围内对土壤有机质分解的影响。结果表明，土壤有机质分解速率随温度升高呈指数增长趋势，且在15℃至30℃区间内增幅最为显著。进一步分析发现，温度升高不仅加速了微生物活性，还改变了土壤微生物群落的结构和功能，尤其是促进了纤维素分解菌的丰度增加。此外，本研究首次揭示了人工林土壤有机质分解过程中存在温度阈值效应，当温度超过30℃时，分解速率的增幅逐渐减缓，表明高温可能抑制部分微生物的活性。研究结果为预测未来气候变化背景下人工林生态系统的碳动态提供了重要科学依据，并为优化人工林管理策略提供了理论支持。

关键词：人工林土壤有机质分解；温度响应机制；微生物活性；纤维素分解菌；温度阈值效应

STUDY ON THE RELATIONSHIP BETWEEN SOIL ORGANIC MATTER DECOMPOSITION RATE AND TEMPERATURE IN PLANTATION

ABSTRACT

The decomposition of soil organic matter in plantation is an important part of carbon cycle in ecosystem, and its rate is significantly affected by environmental factors such as temperature. In recent years, with the global warming, the decomposition process of soil organic matter in plantation and its response mechanism to temperature have become a research hotspot. The purpose of this study was to investigate the variation of soil organic matter decomposition rate under different temperature conditions and reveal its internal mechanism. The effects of temperature between 5℃ and 40℃ on the decomposition of soil organic matter were systematically studied by using static box method and enzyme kinetics analysis in a typical plantation in northeast China. The results showed that the decomposition rate of soil organic matter increased exponentially with the increase of temperature, and the increase was most significant in the range of 15℃ to 30℃. Further analysis showed that temperature increase not only accelerated microbial activity, but also changed the structure and function of soil microbial communities, especially promoted the increase of the abundance of cellulose decomposing bacteria. In addition, this study revealed for the first time that there is a temperature threshold effect during the decomposition of organic matter in plantation soil. When the temperature exceeds 30℃, the increase of decomposition rate gradually slows down, indicating that high temperature may inhibit the activity of some microorganisms. The results of this study provide an important scientific basis for predicting the carbon dynamics of plantation ecosystems under the background of future climate change, and provide theoretical support for optimizing plantation management strategies.

KEY WORDS：Decomposition Of Soil Organic Matter In Plantation; Temperature Response Mechanism; Microbial Activity; Cellulose Decomposing Bacteria; Temperature Threshold Effect

摘要 I

ABSTRACT II

第1章绪论 2

1.1 研究背景及意义 2

1.2 国内外关于人工林土壤有机质分解速率与温度关系的研究现状 2

第2章人工林土壤有机质分解速率的温度响应机制 3

2.1 温度对土壤有机质分解的生物化学过程影响分析 3

2.2 不同温度条件下人工林土壤有机质的分解速率变化规律 3

2.3 温度与土壤微生物活性对有机质分解的协同作用研究 4

第3章人工林土壤有机质分解速率与温度的定量关系模型构建 5

3.1 基于实验数据的温度-分解速率关系模型构建方法 5

3.2 模型参数优化与验证：以中国典型人工林为例 5