WALKER, JILLIAN LEIGH1,2*, T. THYGERSON1,2, BRUCE SMITH2, LEE HANSEN3, R. CRIDDLE3, and ROSEMARY PENDLETON4. 1Brigham Young University Undergraduate Student; 2Botany and Range Science Dept., BYU; 3Chemistry and Biochemistry Dept., BYU; 4Forestry Sciences Laboratory, 2205 Columbia SE, Albuquerque, NM 87106. - Calorimetric Studies of Desert Soil Crust Metabolism in Response to Temperature and Water.
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