sat] values that severely limit downward percolation, such as cemented layers (duripan, petrocalcic), claypans
(abrupt increases in clay content) and strongly contrasting particle size distributions.
Based on definitions offered of deserts and desert environments, the most important factors influencing biological growth and ecological conditions are soil salinity, soil depth, alkaline soils, soil texture, organic matter, evolution, claypans
, soil crusting, groundwater level, and gypsum.
In NSW, it is described as mostly found on flat areas, such as dune swales and claypans
subject to seasonal inundation, in areas of open grassy woodland.
Soils in the sand plains are alkaline red Tenosols, red Kandosols, and Calcarosols with saline, alkaline, grey Vertosols and Sodosols common in the depressions and claypans
, hundreds of which are scattered across the sandplain.
It should be noted that the assemblages at these sites are similar to that described by Veth (1987:105) for claypan
sites in the Great Sandy Desert, although gilgais differ from claypans
in responding much more quickly to rain.
However,' he writes, 'pick the right date and view the landscape from above and a surprising amount of water may be evident on claypans
between the dunes or in wide shallow lakes that cover many square kilometres.
Estimating depth to claypans
using electromagnetic induction methods.
occur where extreme illuviation has caused a very high clay content in a subsoil layer.
Rocky uplands or river valleys may also house true forests, or even vine thickets, while claypans
, wetlands and other landscape features add to the diversity of the regions that are dominated by woodland communities.
These results indicate that the soil depressions on our site are not persistent bison disturbances or relict wallows, but pedogenic features described by rangeland and soil scientists as claypans
or slick or sodic spots (Hazeli, 1965; Culver and Gray, 1968; Bakhtar and Gray, 1971; White and Gartner, 1981; White et al.
0, which is common for claypans
and other restrictive layers and is toxic to roots of most crops," says Foy.
Brian Timms described the river as a complex network of interconnecting channels with permanent waterholes, lignum swamps, rainfed claypans
and salt and freshwater lakes.