EFFECT OF GRAZING INTENSITY ON CHARACTERISTICS OF VEGETATIVE PROPAGATION OF THREE PLANTS IN THE STIPA BREVIFLORA STEPPE

The vegetative propagation characteristics of three main plants under different grazing intensities in the Stipa breviflora desert-steppe were studied.The results showed that the quantity change of modules of plants was affected by different grazing intensities.Light-grazing treatment was more benefit to vegetative propagation of three species,and CK took the second place.The Artemisia frigida had a strong vegetative propagation capability.It could produce plentiful branches and adventitious roots in grazing treatment that occupied largest creeping areas in light-grazing treatment.Rhizomes length of Leymus chinensis decreased by increasing the grazing intensity,and the number of node of the rhizome was largest in heavy-grazing,least in light-grazing,middle position in CK and in moderate-grazing.The number of germination branches of L.chinensis was highest in light-grazing,second in CK and lowest in heavy-grazing,but no significant difference each other.The tiller numbers and coverage of S.breviflora in light-grazing were higher than that in other treatments.The big bunches of S.breviflora were broken into many small bunches in heavy-grazing that increased the density of bunches.