A Method for Selecting Suitable Plant Species to Control of Rill and Gully Erosion in South of Ardabil Province

In this research, a methodology is presented to evaluate the ability of plants for rill and gully erosion control in south of Ardabil province. The plants potential for controlling of concentrated flow erosion was determined based on a multi-criteria analysis. The stem density (SD), top soil erosion-reducing potential of plant roots during concentrated flow erosion (RSD), sediment obstruction potential (SOP), index of plant stiffness (MEI) and root cohesion (Cr) were calculated for 36 native plants (SD=1.216×〖10〗^(-4)-0.28, RSD=3.6×〖10〗^(-42)-10,1076, SOP=0.00082-0.988, MEI=1.69×〖10〗^(-6)-53.471 and Cr=5.432×〖10〗^(-4)-34.62). SD ranges from 0·26 to 28%. The plants Acantholimon talagonicum L. and Festuca Ovina L. have the highest stem density. These are small plant species with a good soil cover in spring and summer. SOP ranges between 0.00128 and 0.988 m/m. The plants Colutea persica Boiss., Melica altissima L., Festuca Ovina L., Verbascum thapsus L. and Amygdalus scoparia Spach have a high potential to obstruct sediment and organic residues. The results of the MEI calculations show that the shrubs and bushs Colutea persica Boiss., Amygdalus scoparia Spach, Tamarix ramosissima Ledeb., Salsola kali L. and Rhus coriaria L. are the most resistant to bending through flow shear forces (5.19-34.626N). Some plants such as Amygdalus scoparia Spach, Glycyrrhiza aspera Pall. or Stipa pennata L. have low RSD value that ranges from 6.68×〖10〗^(-24) to 3.6×〖10〗^(-42), and a high erosion-reducing potential through their roots during concentrated flow. Combined planting of plant species can be more effective in erosion control. The results can be used in adjacent regions and similar cold-semiarid and cold-arid environments.