Despite being a harsh environment, sand dunes are rich in invertebrates, with about 30% (188 species) of the British spider fauna represented (Duffey, 1968), and 53 species being strongly associated with coasts (Ratcliffe, 1977). Arachnologists have examined spider communities in relation to the seral succession of plant communities on sand dunes (e.g. Lowrie, 1948; Barnes, 1953; Perttula, 1984...

Although North American grasslands are diverse and biotically rich, their conservation has never received high priority. As a result, the prairie landscape has all but disappeared. However, one prairie region has retained its essential pre-Columbian features. This is the Nebraska Sand Hills Prairie, a 4.8 million ha stabilized dune region of Holocene origin. Because the Sand Hills lie at the he...

Wind regime and sand grain size are two of the factors that determine the morphology and dynamics of sand dunes in desert areas. Regarding the importance of wind effects on sand dunes especially in Iran, in this study, Khartooran Erg was analyzed to determine wind direction and to detect sand source sites. Khartooran Erg is located on eastern north of Iran and lies in Khorasan Razavi and Semnan...

Silica sand is widely used in the transformation industry. For instance, it is used in the making of glass, silicates, paints, glass-ceramics and ceramics. Traditionally, glass and ceramic materials have been manufactured using high-purity silica and minerals taken from ore on the surface of the earth. However, during recent decades, the manufacture of household and industrial products has incr...

We present a novel approach for numerical simulation of uid ow and sediment transport past evolutionary landforms, with emphasis on sand dunes developing in extreme winds. Time-dependent curvilinear coordinates are employed to fully couple ow aloft with the developing landform. The conservation law that de nes shape of the lower boundary depends on details of local surface stress, thereby favou...

Results from a three-year study are presented that integrate field work (in Israel), physical modeling (wind-tunnel testing at UC Davis), and numerical solutions of grain trajectories to model and explain sand transport over a climbing dune. Field grain-size analyses of surfaceand saltation-trap materials taken along various positions of the slope suggest that only smaller particles (< 230 pm i...

Introduction: THEMIS and MOC images acquired over the Chasma Boreale contain key geologic and stratigraphic information relating to aeolian deposition and the Polar Layered Deposits (PLD). Preliminary analyses of THEMIS VIS and MOC images show a clear progression of morphologic change of dark albedo dune deposits along the chasma axis. Geologic Relations: The source for the dunes appears to be ...

Irreplaceable, self-organizing landforms and the endemic and ecologically specialized biodiversity they support are threatened globally by anthropogenic disturbances. Although the outcome of disrupting landforms is somewhat understood, little information exists that documents population consequences of landform disturbance on endemic biodiversity. Conservation strategies for species dependent u...

Differences in the composition of aeolian sand at Big Dune and Lava that is mixed with basalt various minerals may affect water retention development insects are specialized for living environments. These two dunes, located Nye County, Nevada, home to endemic dune scarab beetle, Pseudocotalpa giulianii (PSGU). The differences type influence growth patterns eggs larvae this beetle species hatche...