This chapter present the principal features and functions of fundamental elements of soil ecosystems. This knowledge is a pre-requisite to understand the importance of global soil biodiversity. Soil is composed of living organisms, minerals, air, water, and perform a number of key environmental, social and economic services that are vital to life. Crucial roles for soil development include different soil-forming factors like parent material, topography, climate, soil organisms and human activities. Soils are formed through the combined effect of physical, chemical and biological processes that operate over hundreds or thousands of years. Over much shorter time scales major changes can occur in the amount and nature of biological activity or hydrological conditions within soils. However, soils are under increasing threats caused by a wide range of human activities (like deforestation and environmental pollution by organic and inorganic toxic compounds). Therefore, an important aim for future soil management is to maintain ecosystem functions and biological diversity. This chapter also explains the importance of different climatic zones for soil development and ends with a fascinating map of global distribution of soils. The soil classification scheme is based on the World Reference Base for Soil Resources (WRB), an internationally used soil classification system.
summary written by Prof. Ellen Kandeler, University of Hohenheim