COVER False-colored laser confocal fl uorescence photomicrograph of Microcoleus vaginatus PCC9802 (blue) and Microcoleus steenstrupii SON82 (red) (image width: 0.3 millimeters). These two cyanobacterial strains are representative of the most abundant microbes in soil crusts of the arid lands in the western United States. M. vaginatus favors cooler climates, whereas M. steenstrupii prefers warme...

COVER False-colored laser confocal fl uorescence photomicrograph of Microcoleus vaginatus PCC9802 (blue) and Microcoleus steenstrupii SON82 (red) (image width: 0.3 millimeters). These two cyanobacterial strains are representative of the most abundant microbes in soil crusts of the arid lands in the western United States. M. vaginatus favors cooler climates, whereas M. steenstrupii prefers warme...

Biological N(2) fixation represents the major source of N input in agricultural soils including those in arid regions. The major N(2)-fixing systems are the symbiotic systems, which can play a significant role in improving the fertility and productivity of low-N soils. The Rhizobium-legume symbioses have received most attention and have been examined extensively. The behavior of some N(2)-fixin...

We compared the pore morphology of an arid lands vesicular soil horizon in a disturbed and undisturbed state. This surface vesicular horizon is characterized by non-connected pores that hinder soil water infiltration and thus plays a central role in arid ecosystem hydrodynamics. Disturbance is hypothesized to result in a change in pore morphology that could alter water movement through the hori...

Management of desert grasslands requires rapid, low technology, coarse assessment methods that provide a triage-like prioritization for the manager. Such approaches necessitate the ability to quickly and effectively identify coarse-scale plant communities that provide guidance for this prioritization. Complex, computer intensive digital image classification of Landsat TM data, while marginally ...

More than one-third of the earth is characterized by arid and semi-arid climate and desertification phenomenon in these areas has been intensified in recent decades. This study aims to investigate the trend of desertification using vegetation indices and Iranian Model of Desertification Potential Assessment (IMDPA) in Abarkooh Plain, Yazd province, Iran. The satellite images (Landsat images in ...

At the beginning of twenty-first century, the water crisis in the priority policy andmanagement is inside and outside of the country as principle thoroughly human, social,economic and political rulers of the country is considered abundant. The World Bank hasannounced that during 1960 and 2025, water resources in Middle East, from 3430 m3 for theeach person in year reach to 667 m3 because of pop...

Soil fertility must be viewed as a dynamic concept that involves the constant cycling of nutrients between organic and inorganic forms. In this context, it refers also to supply adequate amounts water aeration for plant growth. under arid semi-arid lands is constrained not only by limited availability but small matter contents. Most assessment systems are based on contents main parameter. Howev...

Agave is a good source of polysaccharides for the production of fermentable sugars as sustainable bioenergy feedstock solutions for semi-arid and arid lands. This plant grows in arid areas, which correspond to a large territory in northern Mexico. Having lignocellulose as the polysaccharide of interest, the information for the enzymatic saccharification of this kind of material is limited. Agav...