Productivity of Desert Ecosystems

Influence of mesquite (Prosopis glandulosa) on soil nitrogen and carbon development: Implications for global carbon sequestration

“…Sene (1996) estimates that 500 million people live in these drylands and are among the worlds poorest communities lacking the basic necessities of food security, inadequate access to drinking water and inadequate sanitation. While water was deemed to be the unquestioned limit to productivity of arid ecosystems by some workers (Hadley & Szarek, 1981), more comprehensive analyses have suggested that N may be more limiting to sustainable productivity than water (Woodmansee, 1978;Felker, 1998). Due to the importance of organic matter on cation exchange capacity, water infiltration rates, soil bulk density and porosity, it is possible that soil organic carbon may be more important to sustainable plant productivity than water or nitrogen.…”

Intraspecific variation of drought adaptation in brittlebush: leaf pubescence and timing of leaf loss vary with rainfall

“…This developmental response has been considered adaptive in water-limited environments because it reduces water loss and permits the maintenance of photosynthetic activity longer into the drought period (Smith and Nobel 1977;Ehleringer and Mooney 1978;Ehleringer 1983). In the Sonoran and Mojave Deserts, where timing of rainfall and duration of drought can strongly aect plant survival and productivity (Hadley and Szarek 1981;Ehleringer 1994), interpopulation variation of pubescence production in E. farinosa may result from selective pressures related to climatic variability over its range. In spite of its possible importance, little is known about pubescence variation at the geographic and intraspeci®c level, or its ecological correlates (Ehleringer and Clark 1988).…”

Arroyo water storage and soil nutrients and their effects on gas-exchange of shrub species in the northern Chihuahuan Desert

“…Additionally, shrub species growing along the margins of an arroyo were subjected to different conditions, and therefore had Same lower-case letter indicates there were no significant differences between a species at A1 and A2 (LSMEANS, p (0)05). different physiological responses to the same species growing in adjacent nonarroyo areas. Primary production in desert ecosystems is limited by both water and nutrients (for reviews see Hadley & Szarek, 1981;Ludwig, 1987). Arroyos, along with playas, are areas in arid and semi-arid ecosystems that have relatively high moisture levels (Ludwig & Whitford, 1981) where water may be more available and thus, less limiting than in most desert areas.…”