Assessment of the Effects of Overgrazing on the Soil Physical Characteristic and Vegetation Cover Changes in Rangelands of Hosainabad in Kurdistan Province, Iran

Document Type : Research and Full Length Article


1 Faculty of Natural Resources, University of Tehran, Karaj,

2 Combating Desertification Engineering, University of Tehran

3 Combating Desertification Engineering, University of Tehran.

4 Researchers Club, Islamic Azad University, Yasuj Branch,


Soil physical properties have an important role on vegetation growth
through affecting the development of root system. The aim of this study was to
investigate the trampling effect of livestock grazing on soil physical properties and
vegetation cover changes. The experiment was conducted on three range condition
sites (Reference, Key and Critical area) with ten frequencies in Hosseinabade
Kudistan in 2009. Soil physical characteristics consist of humidity, bulk density,
porosity and aggregate stability index. In this study remarked soil cover changes in
three mentioned regions. The results showed that soil moisture reduced from
reference to critical area. Soil bulk density was the lowest in reference area and the
highest in critical area. Reference site had the highest soil porosity while the soil
porosity reduced in critical area. However, as the density of grazing increased, soil
bulk density increased and soil moisture, soil porosity, aggregate stability index and
vegetation cover percent decreased. Bare soil percentage was the highest in critical
region. According to the results of this research, the grazing seems caused to major
changes in the physical properties of the topsoil. Since the region has high
ecological potential, if the intensity of grazing would be in a moderate level, the
region soil will be able to compensate the negative aspects of livestock trampling.