Introduction

Soil is a complex and heterogenous environment that is home to a large diversity of organisms that each play important roles in ecosystem function. The nature of the soil at any given location on the Earth’s surface is important to understand, as fundamental soil characteristics such as texture and porosity influence the productive potential of plants growing there. The soil is a living environment and much of the energy that feeds the soil biota is contributed to soil by plants in the soil. In this way trees and plants influence soil composition and structure and in turn the soil influences the resources supplied to plants.

Objectives

The objective of this module is to review elements of forest soil related to the growth of trees, especially those features of soil that are readily observable in the field.

Upon completion of this module, you should be able to:

• Recognize the basic components of soil and be able to interpret soil horizons
• Describe the physical characteristics of soils in terms of how they impact on plant growth and productivity
• Identify and implement a soil description according to one or more classification systems
• Describe the biological components of soil and be able to discuss the role of different organisms in the decomposition of organic matter
• Evaluate soil properties within a forest management context for restoration and plantation development projects.