Javad Eshaghi Rad - Prof., Dept. of Forestry, Faculty of Natural Resources, Urmia University, Urmia,I. R. Iran
Ahmad Alijanpour - Associate Prof., Dept. of Forestry, Faculty of Natural Resources, Urmia University, Urmia,I. R. Iran
Rouhollah Rostami - Ph.D. Student of Forestry, Dept. of Forestry, Faculty of Natural Resources, Urmia University, Urmia,I. R. Iran

Marmisho valley, located in the north-western Iran, encompasses high species diversity and a unique habitat for birch stands (Betula pendula Roth.). This study was carried out to investigate the vegetation-environment relationship in this area and also to determine the most important environmental factors affecting species distribution with emphasis on the birch species distribution. ۳۰ sample plots were implemented using a random sampling method with a grid size of ۲۰۰ × ۱۰۰ m. At each sampling point, ۴۰۰ m۲ and ۱۰۰ m۲ were set up respectively for recording the cover-abundance of woody species and herbaceous species. Also at the center, a soil sample was taken from ۰-۳۰ cm depth of mineral soil. As a result, ۲۵۱ taxa were observed in Marmisho valley. The results of cluster analysis illustrated that sampling plots were respectively divided into three and five ecological groups based on woody and herbaceous species composition, in which significant differences between different ecological groups were approved by MRPP analysis. In addition, DCA indicated that soil texture and soil pH had the most influence on the distribution of ecological groups in the region. Marmisho valley encompasses high level of plant diversity. Therefore, we need urgent forest management strategies such as protective plan to conserve the region.

Ecological group, Forest Ecosystem, Plant composition, Soil, Iran