The severe degradation of grasslands caused by overgrazing and other diverse human operations has become widespread in Inner Mongolia, China. In this study, the vegetations of several grasslands under different land-use conditions were compared to examine the relationships between the vegetation and the disturbance of the grassland. Floristic and life-form compositions of the stands representing the six different sites were researched by the quadrat method: a non-grazed grassland (G1), a lightly grazed grassland (G2), a path (P), an abandoned field (AF) and two artificial meadows (M1 and M2). P, AF, M1 and M2 were located in a part of the grazed grassland. AF, M1 and M2 had been tilled when planted. The dominant species found in G1 and G2 were Potentilla fragarioides, Poa annua, and Cleistogenes squarrosa. Artemisia annua, Chenopodium album, Cannabis sativa f. ruderalis and Calystegia hederacea were found in P and AF, being scarce in the grassland areas. Amaranthus retroflexus, Kochia scoparia and Setaria viridis, which are cosmopolitan weeds, were dominant only in AF. Leymus chinensis, Agropyron cristatum, Potentilla bifurca, and Potentilla tanacetifolia were widely observed across all the surveyed sites. The land-use change from grassland to path caused a decrease of perennial species and an invasion of annual species by heavy trampling. A similar vegetational change occurred with the land-use change from grassland to abandoned field due to the destruction of original vegetation by tillage. Human disturbance such as tillage and trampling also resulted in a decrease in the species with the tufted-and branchedform and an increase in the species with the erect-form. Tillage could produce a more serious impact on the grassland vegetation as compared to grazing. Flora of Inner Mongolian grasslands M. Ao et al.

The root and rhizome systems of dominant perennial grasses in Inner Mongolian grassland were clarified. We surveyed the vertical distribution of root and rhizome biomass in the natural stands, and the changes of under‐ground biomass and the branching pattern of rhizomes for transplanted plants in a container experiment. Most roots of Leymus chinensis, Bromus inermis, Elymus dahuricus and Agropyron cristatum were distributed in the soil depth of 0–10 cm. Roots of E. dahuricus and A. cristatum were distributed in a shallower soil layer, but those of L. chinensis and B. inermis were distributed in a deeper soil layer. Biomass of above‐ground parts increased with growth, resulting in a decreasing ratio of under‐ground parts to total biomass. Rhizomes of L. chinensis and B. inermis were distributed in the soil depth of 0–10 cm, but E. dahuricus and A. cristatum did not have rhizomes. L. chinensis had longer rhizomes and new ramets were produced away from their mother plant. B. inermis had many short rhizomes and produced daughter plants near their mother plant.

The grassland of Inner Mongolia, China, has experienced a decrease in area. To provide useful information for artificial grassland restoration, the germination characteristics of four native grass species, Leymus chinensis (Trin.) Tzvel., Agropyron cristatum (L.) Gaertn., Bromus inermis Leyss. and Elymus dahuricus Turcz., were compared under laboratory conditions. The seeds of A. cristatum and B. inermis showed >70% germination at a wide range of temperatures from 10 to 30°C with or without light. Seeds of E. dahuricus did not show clear dormancy, but required a rather high temperature (20-30°C) for germination. When the temperature was alternated between day and night, it was the higher of the temperatures (the daytime temperature) that largely determined the percentage of germination. The germination of E. dahuricus was higher (max. 87%) in darkness than in light (max. 58%). Intact seeds of L. chinensis showed considerable germination (47%) only under a widely fluctuating temperature (30/10°C). Additionally, the dehusking of L. chinensis seeds improved the germinability at a constant temperature. These results are suggestive of a different regeneration niche among the four species, which should be taken into account when selecting the species and method for grassland restoration.

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