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In der Diskussion von Equilibrium- vs. Non-Equilibrium-Dynamik von Weideökosystemen hat die Berücksichtigung verschiedener Maßstabsebenen jüngst zur Forderung nach Integration beider Konzepte geführt. Vorliegende Studie untersucht den Beweidungseinfluss in den ariden Wüstensteppen der Westmongolei auf drei räumlichen Maßstabsebenen. Auf der Landschaftsebene wird der Beweidungseinfluss auf die die Vegetation bestimmenden Faktoren beurteilt und beweidungsbedingte Pflanzengesellschaften gesucht. Auf der Ebene von Pflanzengesellschaften werden Gesamtartenzahl, Deckung der Gesamtvegetation, Anteil und Deckung annueller Arten sowie Bodennährstoffparameter entland von Gradienten abnehmender Weideintensität untersucht. Auf der Populationsebene werden Bestandsdichte, Gesamtbiomasse und der Anteil blühender Exemplare des Zwergstrauches Artemisia xerophytica ebenfalls entlang von Weidegradienten geprüft. Die Ergebnisse zeigen einen zunehmenden Beweidungseinfluss mit abnehmendem räumlichen Maßstab. Während auf der Landschaftsebene kein Weideinfluss nachgewiesen werden konnte, reagieren die Vegetationsparameter unterschiedlich auf Beweidung und unterschiedlich in den einzelnen Pflanzengesellschaften. Auf der Populationsebene reflektieren die Ergebnisse deutlich den Weidegradienten in Übereinstimmung mit dem Equilibrium-Modell. Die Studie zeigt equilibriale und non-equilibriale Eigenschaften von ariden Wüstensteppen in Abhängigkeit vom Untersuchungsmaßstab. Die Notwendigkeit mehrerer Maßstabsebenen zur Bewertung von Vegetationsdynamik und Beweidungseinfluss wird dargestellt. Darüber hinaus wird vorgeschlagen, zukünftige Forschungen in einem Vergleich von Landschaften mit und ohne Co-Evolution von Herbivorie durchzuführen. /// For many years, rangeland ecologists have debated about whether the state of semiarid and arid pastures is the expression of an ecological equilibrium dynamics reached in response to grazing livestock. Since the problem having been considered at different spatial scales, it is recognised that the competing concepts of equilibrium and non-equilibrium dynamics need to be integrated. The present study assesses grazing influence in Mongolia's arid desert steppe at three spatial scale levels. At the landscape level, the investigation focused on the impact of grazing on vegetation-determining ecological factors and on the occurrence of grazing-mediated plant communities. At the community level, the total number of species, the total vegetation cover, the percentage of annual species, the cover of annual species, and the soil nutrient properties were assessed along gradients of grazing intensity. At the population level, the total number and weight of plants per plot, individual plant weight and the proportion of flowering plants of the dwarf semishrub Artemisia xerophytica were recorded along gradients of grazing intensity. The results show that grazing influence increases with decreasing spatial scale. At the landscape level, no grazing influence could be identified. At the community level, different vegetation parameters respond to grazing in different ways, and the responses of the same parameters vary between plant communities. At the population level, the results clearly reflect the grazing gradient in the way predicted by the equilibrium model. The study demonstrates that even arid desert steppes display equilibrial and non-equilibrial properties, depending on the observational scale. As a consequence, the assessment of vegetation dynamics and grazing impact in rangelands requires a multiple-scale approach that duly considers climatic differences. It is further suggested, that future research should draw comparisons between landscapes that co-evolved with herbivory, and those that did without.

FloraGREIF presents an internet-based information tool on the vascular plant flora of Mongolia combining taxon- and record-specific information, text and image information with map information and digitized plant specimens with images of living species and their habitats. Based on an updated checklist as taxonomic backbone, information is split into the \"taxon\" and the \"record\" level. At the taxon level the user finds taxonomic diagnoses, habitat information, and species distribution within the floristic regions of Mongolia. The latter is visualized in a Web GIS application. The record level offers information for all records assigned to one taxon, which may include locality data only or additional, high-resolution scans of herbarium specimens combined with images from living species and their habitats. Several query masks allow a flexible search and display of species lists. The interactive Web GIS application links taxon or record information with various map layers, comprising administrative units, topography and orography, floristic regions and vegetation zones of Mongolia. They present background information for the display of species distribution or record localities. FloraGREIF offers a virtual research environment to make the substantial information on Mongolia's flora mainly published in Russian accessible to the public.