Life in the Soil

Abstract

The greatest biodiversity is in the soil, and this chapter describes the soil’s inhabitants—everything from fungi and bacteria to single-celled organisms, mites and other bugs. How are they connected in the foow-webs of the soil? Who eats whom? Fungi and bacteria are important for the decomposition of the organic material in the soil, yet they work in different ways, which affects the circulation of nutrients. Tropical rainforests have a diversity of species above ground whereas in northern latitudes the diversity is to be found under the surface. Certain creatures, such as earthworms, affect the structure of the entire soil ecosystem and accelerate the circulation of nutrients. But when European earthworms invade forests in Minnesota, biodiversity suffers. Termites can eat wood thanks to symbiotic microorganisms in their digestive tract; as they gather material to feed their larvae, they affect the soil’s fertility and the distribution of plants on the savannah. In addition, they have contributed to the cultural development of the Australian Aborigines.

The worms mingle the whole intimately together,

like a gardener who prepares

fine soil for his choicest plants.

Charles Darwin