Seasonal precipitation use by deserts pplants on the Colorado Plateau

The Colorado Plateau (on the left, in white) is a cold desert with about as much precipitation in fall/winter as in spring/summer. Near Moab, Utah, average annual precipitation is 215 mm, but year-to-year variation is high.

The native plant communities of the Colorado Plateau are dominated by perennial grasses, such as Stipa oryzopsis and Hilaria jamesii, sub-shrubs, like Gutierrezia sarothrae , and a large variety of woody shrubs, among them, Ceratoides lanata. These species differ in root characteristics, which affects the way they use soil water.

Measurement of the isotopic composition of plant water makes it possible to determine how much summer versus winter derived water plants are taking up at any time (Ehleringer et al. 1991). Most perennials of the Colorado Plateau, including woody to herbaceous shrubs and sub shrubs, and perennial grasses, take up a mixture of summer and winter water. Some deep-rooted woody plants do not take up any summer rain water. Annuals and succulent perennials take up the most summer rain water.

Experiments with rainout shelters have shown that many C3 plants of the Colorado Plateau, including shrubs and grasses depend greatly on precipitation from November to April for growth. They have very limited use of rainfall from May to September.

For more information, go to the Ehleringer Lab homepages.

Further Reading (download list as pdf file or Endnote file)

Gebauer, R. L. E., and J. R. Ehleringer. 2000. Water and nitrogen uptake patterns following moisture pulses in a cold desert community. Ecology 81:1415-1424.

Gebauer, R. L.E., Schwinning, S. and Ehleringer, J.R. 2002. Interspecific competition and resource pulse utilization in a cold desert community, Ecology 83: 2602 - 2616.

Ehleringer, J. R., Phillips, S. L., Schuster, W. S. F. and Sandquist, D. R. 1991. Differential utilization of summer rains by desert plants. Oecologia 88, 430-434.

Ehleringer, J.R., Schwinning, S. and Gebauer, R.L.E. 1999. Water use in arid land ecosystems. IN: Advances in Plant Physiological Ecology, Press, M.C. (ed.), Blackwell Science, Oxford, pp. 347-365.

Schwinning, S. & Ehleringer, J.R. (2001) Water use tradeoffs and optimal adaptations to pulse-driven arid ecosystems. Journal of Ecology 89: 464-480. pdf file

Schwinning, S., Davis, K., Richardson, L. and Ehleringer, J.R. 2002. Deuterium enriched irrigation suggests three forms of pulse use in perennial species of the Colorado Plateau, Oecologia 130:345-355.pdf file

Schwinning, S., Starr, B. I. and Ehleringer, J.R. 2003. Dominant cold desert plants of the Colorado Plateau do not partition rain by rainfall size, Oecologia 136: 252-260. pdf file

Weltzin, J.F., Loik, M.E., Schwinning, S., Williams, D.G., Fay, P.A., Haddad, M., Harte, J., Huxman, T.E., Knapp, A.K., Lin, G., Pockman, W.T., Shaw, R., Small, E.E., Smith, M.D., Smith, S.D., Tissue, D.T., Zak, J.C. 2003. Assessing the response of terrestrial ecosystems to potential changes in precipitation. Bioscience 53: 941- 952. pdf file

Williams, D. G., and J. R. Ehleringer. 2000. Intra- and interspecific variation for summer precipitation use in pinyon-juniper woodlands. Ecological Monographs 70:517-537.