Plant communities along an elevation gradient under special consideration of grazing in Western Mongolia

Plant communities of semidesert, mountain steppe and alpine vegetation are described in terms of distribution and edaphic conditions along an elevation gradient from the Great Lake Basin to the Central Mongolian Altai in Western Mongolia. References to the Russian classification terminology of corresponding vegetation belts are included. Two new associations and further subassociations are also introduced. The impact of grazing on the presented communities is analysed in a comparable approach along the elevation gradient of decreasing aridity. While no obvious grazing response was detectable in the semidesert vegetation, mountainous vegetation revealed grazing-mediated communities characterised by survivors of the original associations and grazing indicators, by grazing-induced xerophytisation of the vegetation cover and an increasing spatial extent of grazing impact with rising elevations. Evolutionary history reflecting the adaptation of arid and semi-arid ecosystems to grazing and the effective adaptation of management practices to the phenology patterns of vegetation are proposed as important factors of limited grazing impact on arid semidesert vegetation of the study area.