surface. the development of gullies causes the loss of a great amount of soil and could be considered as one of the principal causes of geo-environmental degradation. in this research fazi model introduced for gully erosion zonation in arid and semiarid area considered to calibration and validation in kahkiloeh and boyerahmad province. therefore, the abgandi watershed were selected by considera...

Three transgenic Indian mustard [Brassica juncea (L.) Czern.] lines were tested under field conditions for their ability to remove selenium (Se) from Se- and boron-contaminated saline sediment. The transgenic lines overexpressed genes encoding the enzymes adenosine triphosphate sulfurylase (APS), gamma-glutamyl-cysteine synthetase (ECS), and glutathione synthetase (GS), respectively. The APS, E...

In order to sustainable use of rangelands, it is necessary to recognize water, soil, and vegetation cover and analyze their relationships. Physical and chemical properties of soil are effective in distribution of plant species in local area. To determine the effects of some soil properties on species distribution of Eurotia ceratoides and Stipa barbata in Baghedar summer region of Bafgh, three ...

The aim of the studies was to compare the composition of soil bacterial metabiomes originating from urbanized areas and areas con¬taminated with hydrocarbons with those from agricultural soil and forest soil obtained from a protected wild-life park area. It should be noted that hydrocarbons are everywhere therefore bacteria capable of their utilization are present in every soil type. In the hyd...

One of the most important micro engineers of the terrestrial ecosystems, especially in the arid areas is the harvester ants due to their activity in the soil through nest building; they can make major changes while influencing the surface and subsurface in the rangeland soil. The purpose of this study was to investigate the effects of harvester ants (Messor spp.) on some soil properties in Rood...

The Three Gorges Reservoir Area is one of the most severe soil erosion in China. Serious erosion has degraded the soil productivity, deteriorated the ecological environment, and influenced the service life of Three Gorges Reservoir. The natural and social-economic factors which influence the soil erosion in Three Gorges Reservoir Area include topography, geological situation, vegetation, rainfa...

one of the ordinary methods to protect, rehabilitate, and enhance an ecosystemfunction in arid and semi-arid areas of the world is sand dune stabilization using biologicalpractices. plantation of species on the soil plays a great role in sustainable management ofthe ecosystem. this research studies the effects of cultivation of haloxylon ammodendronand atriplex canescens on physical-chemical ch...

Soil gas radon Rn concentration was measured at 12 location in the Al-Qassim area, using radon gas analyzer-type Alpha GUARD 2000 PRQ from Genitron Instruments (Germany). In each location four different depths were taken for soil gas measurements, staring from the ground surface. The results suggested that the largest concentration was 340 ± 22 Bq/m for 60cm depth at in Al-Tarfia point sample P...

In this study the impact of production work on the skid roads that have been carried out for many years by manpower animal power or machinery in a beech (Fagus orientalis Lipsky) stand have been examined. For this purpose, herbaceous understory, forest floor and soil samples were collected from the undisturbed area and the skid road. Weight per unit area (kg ha(-1)), organic matter ratio and mo...

the objective of this research was to study the relationships between edaphic and topographic factors with distribution of plant species. for this purpose, current study was conducted in eshtehard rangelands of tehran province. the sampling method was randomized–systematic and in each sampling unit, three parallel transects with 750 m length containing 45 quadrates (according to vegetation vari...