1. Department of Forestry, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
2. Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
3. Department of Range Management, Faculty of Natural Resources & Marine Sciences, Tarbiat Modares University, Noor, Iran
4. Department of Temperate Soil Science, Institute of Soil Science, University of Göttingen, Göttingen, Germany