Search results
Results from the WOW.Com Content Network
Spinifex is a genus of perennial coastal plants in the grass family. [2] [3] [4] [5]They are one of the most common plants that grow in sand dunes along the coasts of Africa, Middle East, Asia, Australia, New Zealand, and New Caledonia, with the ranges of some species extending north and west along the coasts of Asia as far as India and Japan. [6]
A dune is a large pile of wind-blown material, typically sand or snow. As the pile accumulates, its larger surface area increases the rate of deposition in a positive feedback loop until the dune collapses under its own weight. This process causes dunes to move in the direction of the wind over time. [6] [7] Death Valley Mesquite Flats sand dunes.
Sand dune ecology describes the biological and physico-chemical interactions that are a characteristic of sand dunes. Sand dune systems are excellent places for biodiversity, partly because they are not very productive for agriculture, and partly because disturbed, stressful, and stable habitats are present in proximity to each other.
Star dunes are formed by variable winds, and have several ridges and slip faces radiating from a central point. They tend to grow vertically; they can reach a height of 500 m (1,600 ft), making them the tallest type of dune. Rounded mounds of sand without a slip face are the rare dome dunes, found on the upwind edges of sand seas. [59]
Psammosere's literal meaning is “originating on sand". It was named by Frederic E. Clements who described the sequence in Plant Succession 1916, [3] although it had also been observed by Henry Chandler Cowles after he conducted several studies on the sand dunes surrounding Lake Michigan, which was influenced by the work of Eugenius Warming.
An erg (also sand sea or dune sea, or sand sheet if it lacks dunes) is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. [1] The word is derived from the Arabic word ʿirq ( عرق ), meaning "dune field". [ 2 ]
Barchans or crescent dunes are produced by wind acting on desert sand; the two horns of the crescent and the slip face point downwind. Sand blows over the upwind face, which stands at about 15 degrees from the horizontal, and falls onto the slip face, where it accumulates up to the angle of repose of the sand, which is about 35 degrees.
A large dune complex is called a dune field, [7] while broad, flat regions covered with wind-swept sand or dunes, with little or no vegetation, are called ergs or sand seas. [ 8 ] [ 9 ] [ 10 ] Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have ...