the study was carried out to investigate the effective soil and topographic features on distribution of plant types in sanib taftan watershed in sistan-and-balouchestan province, iran. initially, land units map was specified by combining three maps of slope, aspect and altitude. five types including artemisia santolina- hammada salicornica, artemisia sieberi- amygdalus lycioides, artemisia lehm...

re-vegetation of bare soil is believed to increase, or at least maintain the organic matter levels of soil. the aim of this study was to investigate the soil characteristics changes, nutrient pool sizes and their availability under mid canopy, and canopy gap positions of saltbush in an area re-vegetated with atriplex lentiformis. some of the physical and chemical soil characteristics (the parti...

the effect of soil and phanerogam characteristics on bryophytes composition, richness, abundance and functional groups were investigated in order to understand the factors responsible for bryophytes distribution patterns. three different sand dunes were selected: untouched, artificial sod-covered and planted by ammophila. along 10 transects perpendicular to the shore, a total of 142 permanent r...

the aim of this study was to investigate relationships between soil properties and plant species to determine the most effective factors separating vegetation communities in rineh rangeland. three stratifying variables were selected including slop, aspect and elevation. the study area was partitioned by combining these classes to generate homogenous units. 1m2 quadrates were located at sampling...

some chemical characteristics of root, shoot and litter of index species such as salsola rigida, artemisia sieberi and stipa barbata commonly used in rangeland development projects were evaluated and compared. chemical properties of soil under and between the above mentioned species were also studied. for this purpose, vegetation types of stipa barbata and artemisia sieberi - salsola rigida wer...

sewage sludge can be utilized as one of the best and cheapest organic fertilizer in agriculture due to its organic and plant nutrient contents. however, the presence of potentially toxic heavy metals in some sludges can restrict its use in agricultural lands. a greenhouse study was conducted in the college of agriculture, ferdowsi university of mashhad, to investigate the effects of leaching an...

this study aimed to investigate the effect of animal grazing on soil seed bank characteristics in the northern slopes of alborz. for this purpose, soil seed bank characteristics were compared between grazed and ungrazed areas. therefore, four transects perpendicular to the sides of exclosure inside and outside of it were established. then soil samples were collected within 28 plots inside and 2...

While social interactions play an important role for the evolution of bacterial siderophore production in vitro, the extent to which siderophore production is a social trait in natural populations is less clear. Here, we demonstrate that siderophores act as public goods in a natural physical environment of Pseudomonas fluorescens: soil-based compost. We show that monocultures of siderophore pro...

Soil is naturally occurring material that is used for the construction of structures except the surface layers of pavements. This naturally occurring soil may not suit the design requirements of ongoing project. So, soil is to be prepared to meet the requirements called soil stabilization. Stabilization is the process of blending of different soils or mixing of additives to a soil to improve ch...