Title: Testing the ecological site concept in Mongolian rangelands. Case study in Undurshireet Soum area

Mongolian rangelands have degraded considerably within the last twenty years following an increase in the number of livestock and changed management. The current land management system has caused decreased herd mobility and overgrazing. This situation calls for new tools for rangeland management based on ecological knowledge, including knowledge on land condition, land potential and the underlying ecosystem functions, or what is collectively referred to as Rangeland Health. Only through such approaches can we expect to achieve sustainable land management. An Ecological Site is a particular area which has its own ecological potential for productivity. A State and Transition Model is a conceptual model describing plant community change pathways under certain sets of disturbances. This approach gives an opportunity to assess land condition and to detect possible changes. Furthermore, an integration of these two enable application of State and Transition Models to help identify states at risk of crossing irreversible ecological thresholds of land degradation and to find appropriate interventions for degraded lands. The purpose of this study was to validate the Ecological Site concept for selected Mongolian rangelands in the Undurshireet Soum area and to test a proposed State and Transition model developed for Stipa Krylovii dominating communities in the Undurshireet Soum area. The results support the main Ecological Sites as they are defined for the Undurshireet Soum area. However, they also suggest that the classification should be simplified to some degree. This is especially true for the calcareous soil sites. The results from reviewing the State and Transition model suggest that an alternative simpler model is more appropriate. Consequently, I suggest that field strategies should be revised in order to collect better data for testing the applicability of State and Transition Models, but the methodology applied here to verify previously defined Ecological Sites appears to be useful.