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The world at your feet: desert biological soil crusts
Author(s) -
Belnap Jayne
Publication year - 2003
Publication title -
frontiers in ecology and the environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.918
H-Index - 164
eISSN - 1540-9309
pISSN - 1540-9295
DOI - 10.1890/1540-9295(2003)001[0181:twayfd]2.0.co;2
Subject(s) - lichen , ecosystem , soil water , desert (philosophy) , ecology , environmental science , nutrient , biological soil crust , cyanobacteria , climate change , geography , biology , philosophy , epistemology , genetics , bacteria
Desert soil surfaces are generally covered with biological soil crusts, composed of a group of organisms dominated by cyanobacteria, lichens, and mosses. Despite their unassuming appearance, these tiny organisms are surprisingly important to many processes in past and present desert ecosystems. Cyanobacteria similar to those seen today have been found as 1.2 billion‐year‐old terrestrial fossils, and they probably stabilized soils then as they do now. Biological crusts are vital in creating and maintaining fertility in otherwise infertile desert soils. They fix both carbon and nitrogen, much of which is leaked to the surrounding soils. They also capture nutrient‐rich dust, and can stimulate plant growth. These organisms are able to tolerate extreme temperatures, drought, and solar radiation, despite having relatively little wet time for metabolic activity. Under most circumstances, they are extremely vulnerable to climate change and disturbances such as off‐road vehicles and grazing livestock. Recovery times are generally measured in decades or centuries.