Effect of vegetation patches as micro-habitats on changing the soil properties (Case study: Saline rangelands surrounding Urmia Lake).

Plants change their environment's characteristics and specially soil properties to develop plant communities during their growth and adaptation. In this study, effects of halophyte patches surrounding Urmia Lake on chemical and physical properties of soil were investigated. In this regard, a vegetation type of Salsola nitraria and Aeluropus littoralis, which represents a broad area of salty pastures around Urmia Lake was chosen for field experiment, so 4 vegetation patches (ecological) were selected and the distance between them was considered as the bare soil without any cover (inter-patch space). Then along two transects with length of 150 meter which were established in parallel to the direct of slope, vegetation patches were measured and soil samples were taken from them and inter-patch spaces with four replications from two depths of soil profile. Soil samples of surface profile were taken from the soil surface up to 15 centimeter depth and the samples of second profile was taken from the depth of 15 to 30 centimeter. After drying the samples, their physical and chemical properties were measured and using independent T-test, the measured parameters were investigated for comparing the ecological patches and inter-patch spaces. The results showed that vegetation patches had significant effect on increasing soil total phosphorus and decreasing soil acidity, electrical conductivity, and soluble salts including sodium, potassium and calcium in soil samples of surface profile (0-15 cm) in patches and inter-patch areas, while there was not any significant difference in nitrogen and silt content of soil from patches and inter-patches. Moreover, comparing these properties in soil samples of second depth (15-30cm) showed that there weren't any significant differences between patches and inter-patches, and these results indicates the effect of vegetation patches and specially their roots on changing chemical properties of surface soil. [ABSTRACT FROM AUTHOR]