Role of fine roots and soil microbes in C, N & P dynamics in a humid tropical forest ecosystem of Northeast India

Inhaltsverzeichnis (Table of Contents)

• CHAPTER 1. INTRODUCTION
• CHAPTER 2. REVIEW OF LITERATURE
• CHAPTER 3. STUDY SITE: LOCATION, GEOLOGY AND SITE CHARACTERISTICS
• CHAPTER 4. VEGETATION AND SOIL
• CHAPTER 5. BIOMASS AND NUTRIENT DYNAMICS OF FINE AND COARSE ROOTS
• CHAPTER 6. DYNAMICS OF SOIL MICROBIAL POPULATION AND BIOMASS -C, -N AND -P
• CHAPTER 7. IN SITU N AND P MINERALIZATION
• CHAPTER 8. GENERAL DISCUSSION
• SUMMARY
• REFERENCES

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This doctoral thesis investigates the role of fine roots and soil microbes in the dynamics of carbon, nitrogen, and phosphorus in a humid tropical forest ecosystem in Northeast India. The study aims to understand the interconnectedness of these components within this specific environment. The key themes explored within this research include:

• The biomass and nutrient dynamics of fine and coarse roots in both undisturbed and disturbed stands of the tropical forest.
• The dynamics of soil microbial populations and biomass in relation to carbon, nitrogen, and phosphorus.
• The in-situ rates of nitrogen and phosphorus mineralization in the forest ecosystem.
• The relationship between vegetation characteristics and soil nutrient content.
• The impact of disturbance on the cycling of carbon, nitrogen, and phosphorus within the forest ecosystem.

Zusammenfassung der Kapitel (Chapter Summaries)

• Chapter 1. Introduction: This chapter provides an overview of the significance of tropical forests in global carbon cycling and their importance as biodiversity hotspots. It highlights the crucial role of fine roots and soil microbes in nutrient dynamics within these ecosystems. The chapter outlines the research objectives and the specific questions addressed in the study.
• Chapter 2. Review of Literature: This chapter reviews the existing scientific literature on the role of fine roots and soil microbes in nutrient cycling in tropical forest ecosystems. It focuses on the key processes involved, such as decomposition, mineralization, and nutrient uptake. It also examines the influence of disturbance on these processes and the potential consequences for ecosystem function.
• Chapter 3. Study Site: Location, Geology and Site Characteristics: This chapter describes the study site in Northeast India, including its geographical location, geological history, and specific climatic and edaphic characteristics. It also provides information on the vegetation and soil conditions within the study area.
• Chapter 4. Vegetation and Soil: This chapter presents data on the vegetation and soil characteristics of the study site. It includes detailed information on the species composition, density, and biomass of different vegetation layers. The chapter also analyzes the physical and chemical properties of the soil, highlighting variations between undisturbed and disturbed stands.
• Chapter 5. Biomass and Nutrient Dynamics of Fine and Coarse Roots: This chapter focuses on the biomass and nutrient dynamics of fine and coarse roots in both undisturbed and disturbed stands of the tropical forest. It analyzes seasonal variations in root biomass and production, as well as the accumulation and turnover of carbon, nitrogen, and phosphorus within different root size classes.
• Chapter 6. Dynamics of Soil Microbial Population and Biomass -C, -N and -P: This chapter investigates the dynamics of soil microbial populations and biomass in relation to carbon, nitrogen, and phosphorus. It examines the abundance and activity of bacteria and fungi in different soil depths and stands, as well as the contribution of microbial biomass to the total soil nutrient pool.
• Chapter 7. In Situ N and P Mineralization: This chapter analyzes the in-situ rates of nitrogen and phosphorus mineralization in the forest ecosystem. It examines the effects of season, stand type, and soil depth on mineralization rates and explores the relationships between these rates and soil physico-chemical and microbial characteristics.

Schlüsselwörter (Keywords)

This research focuses on the important ecological processes of carbon, nitrogen, and phosphorus cycling in a humid tropical forest ecosystem of Northeast India. It examines the role of fine roots and soil microbes in these processes, analyzing biomass, nutrient dynamics, microbial population, and in-situ mineralization rates. Key concepts include forest disturbance, ecosystem function, nutrient availability, and the interconnectedness of different components within this tropical forest ecosystem.