Studying the microbial diversity of a unique biome such as the McMurdo Dry Valleys, Antarctica, is important to understand the sustainability of life under cold-arid conditions where other forms of life (i.e., plants and animals) do not exist. Pointing et al. (1) examined multidomain microbial diversity in the McKelvey valley using culture-independent molecular approaches and interestingly foun...

[1] Soil sulfates are present in arid and hyperarid environments on Earth and have been found to be abundant in soils on Mars. Examination of soil gypsum from the Atacama Desert, Chile, the Mojave Desert, United States, and Al-Jafr Basin, Jordan, revealed endolithic cyanobacteria communities just below the surface of soil gypsum samples. Optical and scanning electron microscope observations of ...

Biological soil crusts are diverse assemblages of bacteria, cyanobacteria, algae, fungi, lichens, and mosses that cover much of arid land soils. The objective of this study was to quantify protozoa associated with biological soil crusts and test the response of protozoa to increased temperature and precipitation as is predicted by some global climate models. Protozoa were more abundant when ass...

analyses and thermal infrared channels 4 and 5 noaa- avhrr images. this research was carried out in lut desert located in center of sub-tropical divergence dominant in' iranian plateau. the physical and thermal properties of the various desert surfaces have been determined using correlation relationships between the desert variables including: dark sand, normal sand, marl, saline soil, soil dep...

Heterothermy plays an important role in lowering the costs of thermoregulation in endotherms by reducing water and energy requirements. We tested predictions that birds in arid habitats should express fine-scale variation in their thermoregulatory patterns as a function of prevailing climatic conditions. We assessed effects of air temperature (Tair) and water vapor pressure deficit (D) on body ...

packed gravel that overlies a thin (3–10 cm), fine-grained, gravel-poor, vesicular A (Av) soil horizon.1 Desert paveDesert pavements are prominent features in arid environments ments are prominent features in arid environments and and consist of a surface layer of closely packed gravel that overlies a thin, gravel-poor, vesicular A (Av) soil horizon. Well-developed Av can be found on a variety ...

Yardangs are one of the most amazing geomorphic features of Lut desert, Iran developed in alluvial deposits of Pleistocene. They appear as the streamlined hills that are separated by U-shaped troughs with a flat-topped. The study of yardang’s morphometric parameters is important to define their morphological indices. In This study, we describe the morphology of yardangs in the Lut playa, analyz...

Episodic recharge as a result of infrequent, high intensity precipitation events comprises the bulk of groundwater recharge in arid environments. Climate change and shifts in precipitation intensity will affect groundwater continuity, thus altering groundwater recharge. This study aims to identify changes in the ratio of groundwater recharge and precipitation, the R:P ratio, in the arid southwe...

Nomadism is found mostly in marginal areas which support only relatively sparse populations, particularly in the arid and semi-arid regions of Africa and Asia. It is a traditional form of society that allows the mobility and flexibility necessary for relatively even use of vegetation over large areas of low quality rangeland. It also facilitates more social interaction than would be possible am...

Previous studies examined the possibility to estimate the aeolian aerodynamic roughness length from satellites, either from visible/near-infrared observations or from microwave backscattering measurements. Here we compare the potential of the two approaches and propose to merge the two sources of information to benefit from their complementary aspects, i.e. the high spatial resolution of the vi...