MATHESON, TAINA. Department of Botany and Range Science, Brigham Young University, Provo, Utah 84604. - Metabolic adaptation of plants to growth season temperature and temperature range along an altitudinal gradient.
We are studying the metabolic adaptation of plants to temperature
along an altitudinal gradient. Seven sites were selected for study,
progressing from near the mouth of Provo Canyon (Utah County, UT) to
just below the summit of Bald Mountain in the Uintas (Summit County,
UT). We used HOBO H8 Pro-Series data loggers to record the hourly
temperatures at each site throughout the 2000 growth season, from June
through August. We identified two herbaceous and one woody species or
congeneric species growing at every site, and collected growing tissue
for calorimetric analysis. The species used were Achillea
millefolium L., Castilleja spp., and Salix spp.
Metabolic heat rates and CO2 evolution rates were obtained at 5, 12,
19, 26, and 33 degrees C. The data show clear differences in metabolic
response between plants of the same species growing at different
altitudes. The hourly temperature data show that each site is
characterized by a different range of temperatures experienced by
plants during the growing season. We hypothesize that the mean
temperature and temperature range will be correlated to the metabolic
response of the plants. This hypothesis leads to a better
understanding of metabolic adaptation of plants. The temperature
loggers are currently in Salt Creek Canyon near Nephi (Utah County,
UT), and we hope to correlate these data to previous calorimetric
measurements on sagebrush grown in the canyon.
Key words: altitude, calorimetry, metabolism, respiration, temperature, treelines