Different effects of woody species with different crown structure on some of the most important qualitative characteristics of soil (Case study: rangelands of Haluposhteh, Baladeh Noor, Mazandaran province)

Rangeland soil is one of the important environmental components that is closely related to the vegetation. Therefore, the aim of this study was to investigate the effect of three types of woody plant species including Juniperus sabina (evergreen and crown attached to the ground), Berberis integerrima (deciduous and open crown) and Onobrychis cornuta (deciduous and cushion), on under the beneath the plant soil caractrisitc. Plant species were selected from the same environmental conditions. Various soil characteristics such as acidity, electrical conductivity, aggregate stability, microbial respiration, total organic carbon and total nitrogen were aimed to be investgated. In late June and early August of 2019, simultaneously with the growth of dominant plants in the middle Alborz rangelands, 20 sites including all three species, were selected and soil samples were taken beneath the crown of each individual in depth of 0-10 cm with an auger (along with 20 control samples, a total of 80 soil samples). Then soil physico-chemical properties were measured in the laboratory. In order to investigate the effect of woody species on soil parameters, one-way ANOVA and Duncan's test were performed. The results showed that the highest amounts of total organic carbon and total nitrogen were observed in the soil under J. sabina (with an average of 3.30% and 0.21%, respectively), while the lowest amount was outside the shrubs, in the control area (with an average of 2.23% and 0.15%, respectively). In addition, the highest percentage of soil moisture was observed under B. integerrima and J. sabina with an average of 5.91 and 5.78, respectively. Changes in the other characteristics of the soil studied were negligible in relation to the woody species. The different effects of different woody species on soil organic matter and nitrogen emphasize the consideration on woody plant species type in rangeland improvement and carbon sequestration projects.