The effects of rangelands improvement and reclamation on vegetation and soil characteristics of Jannat Abad rangelands of Roshtkhar

The cultivation of plants that are resistant in difficult environmental conditions is an effective solution for reclamation of lands; thus, recognizing the effects of cultivation of different plants on soil and vegetation cover could be a suitable guide to select proper species by experts. The aim of this research was to investigate the effects of range improvement and reclamation practices on soil and vegetation cover characteristics in Jannat Abad rangeland. For this purpose, four transects of 100-m length and two transects of 100-m length were established with 100-m intervals in the seedling area (Atriplex canescens and Haloxylon aphyllum) and the control area (natural vegetation), respectively. Along each transect, 10 plots of 4m2 were sampled. In each plot, the vegetation data including canopy cover percentage, litter, gravel, bare soil, dominant species, and plant density were measured. Soil profiles were dug at the beginning and end of each transect. Soil sampling was performed from 0-30, 30-60 and 60-90 cm depths. Then, soil chemical and physical properties including electrical conductivity, pH, organic matter, phosphorus, potassium, nitrogen, bulk density, clay, silt, and sand percentage. The collected data were analyzed by independent t-test with SPSS software. Results showed that the cultivation of Atriplex canescens caused an increase in canopy cover percentage, density, and potassium content in the first and second depths (P<0.01), and caused an increase in the nitrogen content of the first depth, organic matter of the second depth, electrical conductivity of the first and second depths, and silt percentage in the first and third depths (P<0.05). It also caused a decrease in soil pH and sand percentage of the second and third depths (P<0.05). The cultivation of Haloxylon aphyllum caused an increase in density, electrical conductivity of the first depth, and a decrease in clay percentage in the third depth (P<0.05), compared to the control area.