Water Relations and Carbon Dioxide Uptake of Agave deserti - Special Adaptations to Desert Climates

Abstract

Agave deserti Engelm., a common agave of the Sonoran Desert, possesses Crassulacean acid metabolism. Thus, the main period for stomatal opening and net CO, uptake is at night, which leads to a high water -use efficiency. Seedling establishment occurs only when enough water -storage capacity can be generated following germination so that the young seedling can withstand the first drought. Agave deserti is only moderately tolerant of low tissue temperatures but extremely tolerant of high tissue temperatures, an important desert adaptation. Its rosette growth habit leads to a relatively uniform distribution of photosynthetically active radiation over the leaves, which contributes to its high productivity for a desert plant.