Desert soil crusts are communities composed of lichens, cyanobacteria, algae, mosses, and fungi. These integrated soil crusts are susceptible to disturbance, but if intact, appear to play a role in providing essential nutrients, especially nitrogen, to higher plants. It is not currently known how or under what conditions desert crusts grow. Crust samples from localities on the Colorado Plateau, Great Basin, and Grand Junction, CO were collected and rewetted for regrowth. Both metabolic heat rate (q) and carbon dioxide evolution rate (RCO2) were measured in microcalorimeters at temperatures from 0 to 50 degrees Celsius. The temperature dependency of different communities were evaluated, showing differences of growth at different temperatures.

Key words: calorimetry, growth, temperature