Many people think of deserts as inhospitable places devoid of life, but numerous plants and animals have adapted to this harsh environment, where they often compete for limited resources. In desert environments, the most limited resource is usually water, forcing plants to adopt different strategies to compete with their neighbors for this precious resource.
In natural environments, water availability is often stochasticsome years and localities receive lots of rain, while other areas and times remain dry. During dry years, plants that are more efficient with water use often are the most successful. With this success comes a trade-off; in wetter years, these efficient plants may struggle against faster-growing plants.
For deserts, variable weather is common so that plant community patterns can change between wet and dry years, with high densities and a diversity of plants in wet years, and a reduction in both quantity and number of species in dry years. The effect that two important variables have on plant communitiescompetition and water usagewas investigated in the Sonoran Desert by a research group at the University of Arizona and published in a recent issue of the American Journal of Botany.
Jennifer Gremer and colleagues looked at three widespread and abundant plants native to the Sonoran Desert that use different strategies to cope in this variable desert environment by occupying different positions on a trade-off spectrum between relative growth rate and water use efficiency. They interpreted how well plants responded to different conditions, such as high and low water availability and competition, by measuring plant biomass of shoots, stems, and roots.
With the onset of climate change, the deserts are getting hotter and drier, and have been a focus of global change models. "The Sonoran Desert has already begun to exhibit such changes," explains
|Contact: Richard Hund|
American Journal of Botany