Suzuki et al. A phytosociological study in the Eurasian steppe, focusing on the junction of two subregions. In: The East Asian Flora: and its role in the formation of the world’s vegetation

A phytosociological study in the Eurasian steppe, focusing on the junction of two subregions

Kohei SUZUKI¹, Abdisalam JALALDIN², Nurbay ABDUSALIK², Tsagaanbandi TSENDEEKHUU³, Narantsetsegiin AMARTUVSHIN⁴, Takashi KAMIJO¹ & Toru NAKAMURA¹
¹ Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
² Institute of Resource and Environmental Sciences, Xinjiang University, Urumqi, China
³ Department of Botany, Faculty of Biology, National University of Mongolia, Ulaanbaatar, Mongolia
⁴ Institute of Botany, Mongolian academy of Science, Ulaanbaatar, Mongolia

The Eurasian steppe extends as a broad belt across the continent from Hungary to northeastern China (Archibold 1995). It can be divided into two main subregions along the line of Altai Mountains: the Black Sea-Kazakhstan and Central Asian subregions (Lavrenko & Karamysheva 1993). However, the transition of species composition between these two subregions is still unclear. Therefore, this study described the plant communities at the junction of these two subregions. We recorded the species composition in the steppe of northern Xinjiang, China, in 2009, and of western Mongolia in 2010 and 2011, using the phytosociological methods of Braun-Blanquet (1964). In addition, plant communities were classified based on their differential species (Muller-Dombois & Ellenberg 1974). Consequently, two main plant communities were classified: the Stipa capillata-Festuca sulcata community and the Agropyron cristatum-Artemisia frigida community. The Stipa capillata-Festuca sulcata community was found in northern Xinjiang, but not in western Mongolia. The species differentiating this community were Stipa capillata and Festuca sulcata. Conversely, the Agropyron cristatum-Artemisia frigida community was found in western Mongolia, but not in northern Xinjiang. The species differentiating this community were Agropyron cristatum, Artemisia frigida, Caragana pygmaea, Stipa krylovii, etc. We concluded that the Eurasian steppe is divided at the community level along the Altai Mountains. However, a community that was dominated by Stipa krylovii was also distributed in norther Xinjiang. Therefore, some species appeared to cross the Altai Mountains and there are some exceptional communities.