Investigation on relations between salinity agents and vegetation in Kavir Damghan

Study area was selected from Talou farm to Chahjam Kavir in Damghan. Several plant types were distinguished in mentioned site. The types were Artemisia herba alba-Pteropyrum olivieri, Anabasis aphyllaLycium depressum, Tamarix. spp.-Halocnemum strobilaceum, Ha. strobilaceum Halostachys bellangeriana, Ha. strobilaceum-Limonium iranicum. In each plant type, three dominant plant species were selected. Some factors such as moisture percentage (M.P), Sodium (Na), Potassium (K), Calcium (Ca), Magnesium (Mg), Chloride (Cl) and Sulfate (SO4) were measured in plants roots and stems. A profile was dug in each plant type and some factors such as texture, acidity (pH), electrical conductivity (ECe), organic matter (O.M.), lime percentage, soluble ions (Ca, Mg, K, Na, Cl, SO4), M.P and cation exchange capacity (CEC) were determined too. Plant and soil samples were taken in spring and summer seasons. According to amounts of ECe in soils and dry weight of plants, rangeland plants were classified from high to low resistance to salinity as following as: 1) Ha.strobilaceum 2) Tamarix sp. 3) Ha. Bellangeriana 4) Li.iranicum 5) Al.camelorum 6) An.aphylla 7) Ly.depressum 8) Pr.fracfa 9) Ar.heba alba 10) Pt.olivieri Relationship between soil factors and plant characteristics were obtained by regression analysis. Amount of elements in plant can be distinguished by amount of soil elements and vice versa. Other results show that sodium element is the best index for resistance to salinity after electrical conductivity.