The relationship between edaphic factors and the spread of compatible plant communities in watersheds with salt dome

Proper watershed management is based on ecological principles, and understanding the ecological process is the main prerequisite for natural resource planning. The watersheds adjacent to the Oman Sea and the Persian Gulf have special conditions compared to other watersheds in the country, such that these watersheds have many salt domes. These geomorphological facies affect the quality of underground water in the areas and require special management techniques. Among the ecological factors, soil is one of the factors that play an important and influential role in the distribution and density of vegetation. The strong correlation and close relationship between vegetation and soil are such that a change in the status of each will have a very strong impact on other ecosystem functions. The present study was conducted to investigate the changes in plant communities and the role of soil factors on these communities in these Gulf and Omani vegetation areas in Bastak city of Hormozgan. 

For this purpose, after determining the desired area, using Google Earth satellite images and ground control, typing was performed and then sampling was done in each type on three transects of 1000 meters with a plot of 4 square meters with a suitable distance. In each plot, canopy percentage, density, height, and two diameters perpendicular to each other of dominant plants were measured. To study the soil, 9 profiles were dug in each type and sampled from two depths of 0 to 45 and 45 to 90 cm and transferred to the laboratory. Statistical analysis was performed by SPSS software and a comparison of means by Duncan method in a randomized complete block design. 

The results show that during the 20 years of 1379-1399, all land uses have undergone drastic changes. In this period, pastures have decreased by 18.32%, of which 83.50% belong to pastures, 9.85% to saline and barren lands, 0.70% to urban-man-made areas, and 5.95% to agricultural lands. The results of the correlation coefficient analysis indicate that the vegetation parameter was electrically correlated with the amount of sodium at 95% statistical level. The height of plant species is related to the percentage of saturated moisture and the percentage of silt in the first and second depths. Showed a negative correlation with soil acidity at both depths with a negative approach at 95% level. 

Soil salinization and its development in dry and semi-arid fragile watersheds is one of the environmental hazards that has received attention in recent years. Faramarzan city of Bastak is one of the areas that have arid and semi-arid environmental conditions and one of the environmental hazards of this watershed is salinization and salinization of lands. In summary, it can be stated that the trans-border area of Bastak is limited by the salt marshlands of Hormozgan in the high areas with salt domes and in the lower areas with the salty river. The type of plant species in the plant types in this salt marsh was different according to the salinity center, and this difference is the result of the soil charact.