Pastoral Degradation of Steppe Ecosystems in Central Mongolia

Abstract

In a close comparison of grazed and protected stands along a long submeridian transect next to the trans-Mongolian railway (Sukhe-Bator – Ulaanbaataar – Dzamyn-Ud) across several subzones of the Mongolian steppes we studied cover, species composition, and aboveground phytomass. In about all main types of steppe overgrazing led to the spread of bushes. In mountain-meadow and meadow steppes overgrazing tends to lead to dominance of Artemisia frigida and Caragana pygmaea; in true and dry steppes with C. microphylla and Artemisia frigida; in deserti fi ed (dry) and desert steppes with Caragana stenophylla and C. korshinskii. Subdominants, depend on subzonal type of steppe and can include Artemisia adamsii , Carex duriuscula , Convolvulus ammanii , Leymus chinensis , Potentilla acaulis and Sibbaldianthe adpressa. When grazing loads increase it can to strongly monodominant communities.