PARENT SESSION
Oral Session # 77: Plant Ecology VI: Temperature and Water Stress.
Presiding: C Ford
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Meeting Room 102.

Metabolic response to temperature in blackbrush (Coleogyne ramosissima).

Summers, Heidi¹, Smith, Bruce¹, Hansen, Lee¹, ¹ Brigham Young University, Provo, UT

ABSTRACT- Blackbrush (Coleogyne ramosissima Torr.) is a desert shrub that grows in a defined mid-elevational band in the southwestern United States. Seeds gathered from populations at varying elevations in the Mojave Desert and Colorado Plateau were germinated and grown at 15°C. The grown tissue was placed in calorimeter ampules, and the metabolic heat rate (R_q) was measured at several temperatures. Then a vial containing NaOH was placed in each ampule to measure the rate of CO₂ evolution (R_CO2) at each temperature. Rates were measured at temperatures from 5 to 35°C. The measurements were used to calculate metabolic efficiency and to predict specific growth rates. Preliminary results indicate optimum temperatures for metabolism and growth range from 10 to 35°C, showing differential adaptation among populations.

Key words: calorimetry, Coleogyne ramosissima, metabolism