Filters: Tags: Desert shrubs (X)4 results (66ms)
Hydraulic lift: Substantial nocturnal water transport between soil layers by Artemisia tridentata roots
Diel soil water potential fluctuations reflected daytime depletion and nocturnal resupply of water in upper soil layers. Transpiration suppression experiments demonstrated that water absorption by roots caused the daytime depletion. The soil water potential data and experimental results suggest that at night water absorbed from moist soil by deeper roots is transported to and lost from roots into drier upper soil layers. The deeper roots appear to absorb and transport water both day and night. Implications for the efficiency of deep roots and water storage, nutrient uptake and water parasitism in upper soil layers are discussed. Published in Oecologia, volume 73, issue 4, on pages 486 - 489, in 1987.
Shrubs of the Great Basin desert in Utah are subjected to a prolonged summer drought. One potential consequence of drought is a reduced water transport capability of the xylem. This is due to drought-induced cavitation. We used the centrifuge method to measure the vulnerability of root and stem xylem to cavitation in six native shrub species. The shrubs fall into three categories with regards to rooting depth, vegetative phenology and plant water status during drought. The â€œsummer greenâ€� group (Chrysothamnus viscidiflorus, Atriplex canescens, Atriplex confertifolia) sustains summer drought with a relatively shallow root system (<2.5 m), but maintains leaf area. A â€œdrought deciduousâ€� group (Grayia spinosa,...
In the northern stretches of the Chihuahuan Desert, the margins of ephemeral stream channels called arroyos support a unique vegetation dominated by a guild of winter-deciduous shrubs. To explore the dynamics of nutrient conservation in this assemblage of arroyo shrubs, we measured nitrogen (N) and phosphorus (P) resorption efficiency and proficiency in six species of shrubs growing in arroyos in southern New Mexico, USA. Collectively, these six species were no more efficient or proficient at resorbing N and P from senescing leaves than shrubs growing in other environments. Resorption efficiency averaged 53% and 50% for N and P, respectively, and resorption proficiency averaged 0.80% and 0.06% for N and P, respectively....
South-eastern Utah forms a northern border for the region currently influenced by the Arizona monosoonal system, which feeds moisture and summer precipitation into western North America. One major consequence predicted by global climate change scenarios is an intensification of monosoonal (summer) precipitation in the aridland areas of the western United States. We examined the capacity of dominant perennial shrubs in a Colorado Plateau cold desert ecosystem of southern Utah, United States, to use summer moisture inputs. We simulated increases of 25 and 50 mm summer rain events on Atriplex canescens, Artemisia filifolia, Chrysothamus nauseosus, Coleogyne ramosissima, and Vanclevea stylosa, in July and September...