Microbes and Microfauna Associated with Biological Soil Crusts

Abstract

Microbial populations play a critical role in the regulation of nutrient cycling and energy flow in ecosystems, as they mediate decomposition and subsequent mineralization rates which, in turn, regulate nutrient availability and primary production (Zak and Freckman 1991). Even in regions where water is considered limiting, nutrient availability can restrict plant growth (Romney et al. 1978). Extreme temperatures and/or low soil moisture restrict soil food web development. As soil favorability increases, edaphic taxa generally appear in the following order: pigmented bacteria > actinomycetes > algae and cyanobacteria > fungi, protozoa, other bacteria > lichens > mosses and microarthropods (Cameron et al. 1970).