plants and arthropods are the main elements of biodiversity in ecosystems. in order to evaluate structural biodiversity of plants and arthropods in natural systems of arid land, a study was carried out in shirvan, mashhad and gonabad, three regions of razavi and northern khorasan provinces, iran. in each region, 10 areas of natural systems selected and sampling was done in these selected areas....

soil erosion is a major problem for developing countries with arid and semi-arid climate. these of erosion is possible than two ways of water and wind. in this paper, with using of two methods irifer and hierarchical models, the rate and intensity of of soil erosion is estimated shadegan catchment. for this purpose, by using various maps alike dem, rainfall, land use index, ndvi, geology estima...

In many semi-arid environments, vegetation is self-organised into spatial patterns. The most striking examples of this are on gentle slopes, where striped patterns are typical, running parallel to the contours. Previously, Klausmeier [1999. Regular and irregular patterns in semiarid vegetation. Science 284, 1826-1828.] has proposed a model for vegetation stripes based on competition for water. ...

metric (mapping evapotranspiration at high resolution with internalized calibration) is known as an appropriate surface energy balance model for the estimation of the spatial distribution of evapotranspiration (et) in semi-arid regions. based on lysimeter measurements, metric has shown et estimates of 10% on a sub-field scale on a daily basis. there is a need to identify how the model is sensit...

this study was conducted to determine the prevalence and effect of parasitic infection on erythrocyte indices in trade camels slaughtered in maiduguri, nigeria. two hundred adult one humped camels comprised of 87 (43.5 %) males and 113 (56.5 %) females were examined for helminths and hemoparasites at their slaughter time according to the standard procedures. an overall prevalence of 79 % for si...

objective: more than 75 percent of iran is located in arid and semi-arid then land degradation and desertification are one of the crises ecological. we require a proper understanding of causes and processes of desertification to control the huge phenomenon on the global and regional situation. because southeast of iran located in arid land then assessment of desertification is very importance f...

The objective of this paper is to provide an overview of the primary results of the Semi-Arid Land–Surface–Atmosphere (SALSA) Program in the context of improvements to our overall understanding of hydrologic, ecologic, and atmospheric processes and their interactions in a semi-arid basin. The major findings and future research needs associated with the different core components of the program a...

northern khorasan province is located in north-east iran. according to demarton coefficient, it is a semiarid region. arid and semi-arid or subhumid zones are characterized by temperature variations, low and erratic rainfall, periodic droughts and different associations of vegetative cover and soils. this article looks at current dry lands and general guidelines for finding the best area for dr...