Topic 1: Soil Development

Introduction

In this topic you will examine how soils develop, and how they can be damaged by inappropriate management actions. Soils are critical to forests. They provide the rooting medium for trees, and to a certain extent determine the productivity of the forest. The development of soils is dependent on a range of factors, including the parent materials, the climate and time. In turn, the vegetation of forests is dependent on the soil, the climate, past disturbances and other factors. Understanding these critical relationships is an important aspect of sustainable forest management.

Under natural conditions, soils develop over time unless that development is disturbed by some external factor, such as a period of erosion following a natural disturbance. Forest operations that fail to respect the soil can also trigger soil degradation, as can land-use practices such as grazing livestock within forests. A more recent concern is that intensive plantation forestry, particularly fast-growing plantations, might exhaust the nutritional capacity of a soil, and this is also examined in this module.