Shadi Hazhir; Reza Erfanzadeh; Hassan Ghelichnia; Bahar Razavi; Peter Torok
Abstract
This research was conducted with the aim of comparing the effect of livestock grazing on the soil seed bank and some soil characteristics in two saline and non-saline regions. For this purpose, two habitats with different degrees of salinity were selected in Golestan province, Iran. In each region, two ...
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This research was conducted with the aim of comparing the effect of livestock grazing on the soil seed bank and some soil characteristics in two saline and non-saline regions. For this purpose, two habitats with different degrees of salinity were selected in Golestan province, Iran. In each region, two sites of grazed and ungrazed (20 years) were selected and 15 plots of 1 m2 were established at each site. Soil samples were taken from inside the plots by auger at two depths of 0-5 and 5-10 cm. The harsh environmental conditions prevailing in the saline habitat caused no seeds from the soil of this saline region to germinate in the greenhouse. In the non-saline habitat, the removal of livestock grazing caused a significant increase in the density of the soil seed bank. The highest density, diversity and richness of the seed bank were respectively 1389.50 (m2), 1.24 and 5.2 in ungrazed site at the depth of 0-5 cm, and the lowest values were respectively 173.26 (m2), 29.0 and 1.46 were recorded in the grazed site at the depth of 5-10 cm. Although the soil characteristics such as organic matter and nitrogen were not significantly affected by the removal of grazing in the non-saline area, soil disturbance in the grazed site probably led to an increase in soil surface temperature and a significant increase in substrate-induced respiration and urease enzyme activity was reduced. In the saline soil, the grazing removal caused the soil characteristics to show different responses. At the ungrazed site, pH and basal respiration decreased significantly
Ghasem Ali Dianati Tilaki; Aliyeh Keshavarz; Bahram Amiri; Ehsan Sadati
Abstract
Effect of salt stress on the stomata variations was studied in Hedysarumcoronarium L. and HedysarumcriniferumBoiss., using optical microscope. The experimental design was a two factorial (species treatments and salt concentrations including 0, 100, 200, 250 mMNaCl) which arranged in a completely randomized ...
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Effect of salt stress on the stomata variations was studied in Hedysarumcoronarium L. and HedysarumcriniferumBoiss., using optical microscope. The experimental design was a two factorial (species treatments and salt concentrations including 0, 100, 200, 250 mMNaCl) which arranged in a completely randomized design with four replicates and 50 seeds per replicate. Seeds were grown in plastic pots with sterile sand. All pots were irrigated by distilled water until germination stage. Then the pots were irrigated uniformly every other day with modified Hoagland’s nutrient solution during 40 days and finally stomata traits were measured. The data was analyzed using SPSS software. The difference between the means was compared using Duncan test (P<0.05). Results showed that the lowest amount of the stomata length, stomata width and area of stomata were observed at 300 Mm salinity stress. Length and width of stomata were reduced by increasing salinity stress. The length stomata decreased 22.33 and 23.76 (μm) for H. coronarium and H. criniferum respectively, while width stomata decreased by 17.13 and 18.62 (μm) respectively. The area of stomata decreased 397.11 and 442.83 (μm²) for H. coronarium and H. criniferum respectively. Salinity stress had positive effect on stomata density (mm²). The highest density of stomata was found in H. criniferumin 250 and 300 mM salinity levels.
