BACKGROUND After comprehensive study of various superhydrophobic phenomena in nature, it is no longer a puzzle for researchers to realize such fetching surfaces. However, the different types of artificial surfaces may get wetted and lose its water repellence if there exist defects or the liquid is under pressure. With respect to the industry applications, in which the resistance of wetting tran...

Understanding the unusual radar scattering characteristics of sand dunes is necessary in the analysis of radar images of aeolian landscapes of the earth and of other planets. In this paper we report on airborne radar scatterometer data of sand dunes, acquired at multiple frequencies and polarizations. Radar backscatter from sand dunes is very sensitive to the imaging geometry. At small incidenc...

the effect of soil and phanerogam characteristics on bryophytes composition, richness, abundance and functional groups were investigated in order to understand the factors responsible for bryophytes distribution patterns. three different sand dunes were selected: untouched, artificial sod-covered and planted by ammophila. along 10 transects perpendicular to the shore, a total of 142 permanent r...

[1] Submarine groundwater discharge (SGD) into the ocean is increasingly recognized as an important component of land-ocean interaction. Numerous geological settings may be the source of terrestrially derived SGD, including spatially extensive sand dune systems, which are a common coastal setting in tropical, subtropical, and temperate regions throughout the world. Within the catchment of the G...

Occasional fog is a critical water source utilised by plants and animals in the Namib Desert. Fog basking beetles (Onymacris unguicularis, Tenebrionidae) and Namib dune bushman grass (Stipagrostris sabulicola, Poaceae) collect water directly from the fog. While the beetles position themselves optimally for fog water collection on dune ridges, the grass occurs predominantly at the dune base wher...

Preliminary results are reported from an experimental study of the interaction between turbulence, sediment transport and bedform dynamics over the transition from dunes to upper stage plane beds. Over the transition, typical dunes changed to humpback dunes (mean velocity 0.8 ms-', depth 0.1 m, mean grain size 0.3 mm) to nominally plane beds with low relief bed waves up to a few mm high. All be...

Habitats that differ in soil resource availability are expected to differ for selection on resource-related plant traits. Here, we examined spatial and temporal variation in phenotypic selection on leaf ecophysiological traits for 10 Helianthus populations, including two species of hybrid origin, Helianthus anomalus and Helianthus deserticola, and artificial hybrids of their ancestral parents. ...

The structure of the barchan field located between Tarfaya and Laayoune (Atlantic Sahara, Morroco) is quantitatively investigated and compared to that in La Pampa de la Joya (Arequipa, Peru). On the basis of field measurements, we show how the volume, the velocity and the output sand flux of a dune can be computed from the value of its body and horn widths. The dune size distribution is obtaine...

Studies of sand saltation are currently concentrating on wind tunnel experiments, theoretical analyses and numerical simulations under ideal as well as controllable conditions. These theoretical analyses and numerical simulations cannot accurately predict sand movements in field environments. In this paper, we simulate wind field patterns for two different surfaces of complex microtopography us...

Ants known for attacking and killing hatchling birds and reptiles include the red imported fire ant (Solenopsis invicta Buren), tropical fire ant [Solenopsis geminata (Fabr.)], and little fire ant [Wasmannia auropunctata (Roger)]. We tested whether sea turtle nest placement influenced exposure to predaceous ants. In 2000 and 2001, we surveyed ants along a Florida beach where green turtles (Chel...