Abstract

There is this growing trend of using medicinal plants and traditional medicine. Considering the types and diversity of these plants and identifying the effect of management measures on their quality and quantity can affect their development. In this research, in Bozdaghi Region, arid and semi arid rangelands in Maneh-o-Samalghan City of North Khorasan Province, the effect of livestock grazing on types and diversity of medicinal plants is considered. With selection of two enclosures and under grazing area, a number of 100 plates with one square meter are randomly located. The percentage of plant cover and type of medicine density is measured. For this purpose, diversity parametric indices including log series, log normal, geometric model and broken stick McArthor are assessed by using Bio-Dep software. For consideration of significance of measured levels, Ki-Square test is used. The results show that the grazed area tends to Log model and Log- Normal; thus the enclosure causes increase in ecological capacity and species diversity of medicinal plants. The logarithmic curve of frequency-level distribution in under grazing area has a lower level than enclosure area and also both follow log series and Log-Normal. Therefore, that means this region at first is a uniform region but has tended to Log series due to livestock grazing. As a result, we can conclude that this region is an under stress area. Therefore, livestock grazing causes a decrease in diversity of medicinal species in the region.

Key words: Medicinal plants, livestock grazing, frequency-level curve, log-normal series, geometrical model.