Ecological study of Betula pendula stands in Hyrcanian forests, north Iran

Abstract

This study was carried out in the rocky forests of Dodangeh, south of Sari, an area extended as a narrow strip from east to west in the heights of Hyrcanian forests, with the area of ca 2, 000 ha and the altitude of 2, 500-2, 950 m a.s.l. Regarding vegetation history, Dodangeh is a refuge for Betula pendula Roth. This species together with Corylus avellana L. are the first ones formed a plant community in Hyrcanian region since the glaciation of the Tertiary period and gradual retrogression of conifers. A number of 181 plant species belonging to 52 families were identified through sampling of 20 relevés of the size 400 m2. Out of these, 17% were endemic of Hyrcanian and Irano-Turanian regions including four species viz. Aconitum iranshahrii Renz., Cortusa mathioli subsp. iranica, Delphinium elbursense var. elbursense and Doronicum wendelboii which could be found nowhere else in the world. Querco macran-therae-Betuletum pendulae association is recorded in the Hyrcanian and Euro-Siberian regions for the first time. Chorological studies of Querco macrantherae-Betuletum pendulae showed that the elements of Irano-Turanian, Euro-Siberian and Hyrcanian regions are more than those of the other existing vegetational regions in the area. Dynamic processes of this association and its restoration were also considered in the study. © 2004 Akadémiai Kiadó, Budapest.