The Mina and Everard Goodman Faculty of Life Sciences Bar-Ilan University Ramat-Gan 5290002 Israel;
The School of Zoology George S.Wise Faculty of Life Sciences and The Steinhardt Museum of Natural History Israel National Center for Biodiversity Studies Tel Aviv University Tel Aviv 6997801 Israel;
Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwestern China of Ministry of Education Ningxia University Yinchuan 750021 China;
Grazing; soil disturbances; environmental factors; biological indicators; ecological index;