title: The role of dew in Negev Desert plants.
abstract: We investigated the possible use of dew as a water source for three desert plant species native to the Negev Desert: an annual Salsola inermis, and two perennials Artemisia sieberi and Haloxylon scoparium, with different rooting depths of 15, 30 and 90 cm, respectively. We quantified dew-water inputs and used stable isotope analyses to determine the proportion of dew as compared to the proportion of soil water each species utilized. Dew was isotopically enriched (δD values ranged from -25 to 5 ‰), relative to rainfall with δD values that ranged from -40 to -20 ‰ and relative to soil water with δD values that ranged from -65 to -35 ‰. Using a two-source isotope mixing model, we found that S. inermis, A. sieberi and H. scoparium used, on average, 56, 63 and 46 % of their water from dewfall, respectively. Our results suggest that dew-water utilization by Negev Desert plants is highly significant ecologically and thus may be more common than previously thought. In light of future predicted climate change, it may be increasingly important for plants of the Negev Desert to make use of dew as a water resource as it may play an important role in their ability to cope with the associated hydrological constraints predicted for the Negev region.
authors.affiliation: The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus Midreshet Ben-Gurion, 84990, Beersheva, Israel, ecoamber@gmail.com.
authors.forename: Amber J
authors.initials: AJ
authors.lastname: Hill
authors.forename: Todd E
authors.initials: TE
authors.lastname: Dawson
authors.forename: Oren
authors.initials: O
authors.lastname: Shelef
authors.forename: Shimon
authors.initials: S
authors.lastname: Rachmilevitch
mesh_terms: D027703:Amaranthaceae / Q000737:chemistry / Q000378:metabolism*; D019306:Artemisia / Q000737:chemistry / Q000378:metabolism*; D057231:Climate Change; D003889:Desert Climate; D003903:Deuterium / Q000032:analysis; D010103:Oxygen Isotopes / Q000032:analysis; D031248:Salsola / Q000737:chemistry / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D014867:Water / Q000032:analysis* / Q000378:metabolism*
chemical_list: D010103:Oxygen Isotopes; D012987:Soil; D014867:Water; D003903:Deuterium