Investigating the Sustainability and Interactive Effects of Physical-chemical Properties of Erosion-sensitive Marl and Rangeland Vegetation in Arid and Semiarid Areas (Case Study: Shahrood Town)

Marni Formations have little vegetation in most arid and semi-arid regions due to special physical and chemical properties. The establishment of coverage on them faced several limitations. To properly understand the state of ecosystems in arid and semi-arid regions, it is necessary to understand the dynamic relationship between vegetation and soil. The aim of this study is to identify the established plant species and to investigate the interactive effects of physical-chemical characteristics of erosion-sensitive marl and rangeland vegetation in marl formations in three regions (Taroud Roads, Bakran and Riabad) of Shahroud city; so that after delimiting the marl lands on topographic maps and using geological maps, soil sampling was performed to determine the characteristics and to measure the vegetation canopy. Moderate erodibility in Marni formations in three areas, Taroud Roads, Bakran and Riabad, was done using BLM model. The results show that in general, the erosion status by BLM method in Bakran region with the highest percentage of vegetation is in the lower class and in the area of Taroud Roads and Riabad is in the middle class. The results of correlation between physicochemical indices of soil and vegetation showed that the canopy factor was related to soil factors including gypsum percentage (CaSo4) and clay percentage at 99% and 95% confidence levels, respectively affecting each other. Clay in marl soil of Shahroud city is one of the most important factors that play an important role in the establishment of vegetation. The important point is that in all three regions, there is an abundance and predominant species of Artemisia plain and, without a doubt, this rangeland species can be considered as the most compatible plant species in the areas covered by marl formations.