Substantial tracts of land in the southwestern and western U.S. are undergoing or will require ERA. Toxicity bioassays employed in baseline ERAs are, for the most part. representative of mesic systems, and highly standardized test species (e.g., lettuce, earthworm) are generally not relevant to arid system toxicity testing. Conversely, relevant test species are often poorly characterized with r...

Irrigation-induced salinization is an important land degradation process that affects crop yield in the Brazilian semi-arid region, and gypsum has been used as a corrective measure for saline soils. Fluvent soil samples (180) were treated with increasing levels of salinization of NaCl, MgCl2 and CaCl2. The salinity was gauged using electrical conductivity (EC). Gypsum was added to one split of ...

abstract soil microbial activity and biochemical processes are often limited by carbon availability in arid- and semi-arid regions, probably due to the low organic matter content. consequently, return of plant residues to soil is a convenient and effortless practice for increasing microbial activities and biochemical reactions. the primary objective of this study was to evaluate the effect of v...

Improving the capability of land-surface process models to simulate soil moisture assists in better understanding the atmosphere-land interaction. In semi-arid regions, due to limited near-surface observational data and large errors in large-scale parameters obtained by the remote sensing method, there exist uncertainties in land surface parameters, which can cause large offsets between the sim...

This paper reports a practical application of digitally enhanced Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) data coupled with principal component analysis (PCA) and spectral angle mapping (SAM) techniques to assess changes in vegetation and land condition within the U.S. Army installation at Fort Bliss, Texas. Fort Bliss is located in a semi-arid desert environment wh...

Exotic species can threaten native ecosystems and reduce services that ecosystems provide to humans. Early detection of incipient populations of exotic species is a key step in containing exotics before explosive population growth and corresponding impacts occur. We report the results of the first three years of an exotic plant early detection and treatment program conducted along more than 3,0...

Drought is a major problematic phenomenon mostly for semi-arid areas of Iran. During drought periods, reduction in vegetation levels causes such problems as soil erosion, surface runoff, flood risk, etc. Therefore, the assessment of drought effects on plant covers is the most important issue. This research was conducted in 2015 using the extracted vegetation indices from Moderate Resolution Ima...

soil hydrau-physical data are important for many hydrological modelings. they are the main variables controllingthe key processes such as water and chemicals movement and transport in the soil profiles. this study was conductedin order to analyze the spatial distribution of selected soil hydrau-physcial characteristics including infiltration rate(ir), saturated hydraulic conductivity (ks), bulk...

The extent to which leaf water D-enrichment (transpiration) and soil water D-enrichment (evaporation) affect the D/H ratio of plant leaf waxes remains a contentious issue, with important implications for paleohydrologic reconstructions. In this study we measure dD values of precipitation (dDp), groundwater (dDgw), plant xylem water (dDxw) and leaf water (dDlw) to understand their impact on the ...

soil erosion by water is the main factor of land degradation, particularly in semi-arid regions where soil productivity is usually low and lowering soil quality can severely decrease crops yields. this study was done in an area of 900 km2 in the semi-arid agricultural region of hashtroud in northwestern iran to determine the relationship between soil productivity and soil erodibility. wheat gra...