Study on the grassland type and productivity of Tanzi pasture in Danchang County

The productivity and carrying capacity of Tanzi pasture in Tanchang County, Gansu Province, was investigated and charted by GIS in July 2008. The total area of grassland was 2 449 ha. The grassland belonged to montane meadow type, and had 3 groups and 8 formations. The forb group included 3 formations, that was Umbelliferae + Anemone rivilaris + Carpesium cernuum, Polygonum viviparum + Kobresia + Saposhnikovia divaricata, Iris ensata+Anemone rivilaris + Cirsium. The sedge group included 2 formations, that was Blysmus + Ligularia, Bysmus + Potentilla + Pedicularis. The shrub group included 3 formations, that was P. fruticosa+Salix + P. viviparum, P. fruticosa + P.viviparum + Potentilla,Daphne giraldii + Saposhnikovia divaricata + Anemone rivilaris. The forage yield was 3 078 t/ha under the grazing intensity of 50%， the carrying capacity was 2 810 sheep units. To improve the grassland productivity, the ways of reseeding,cutting and rotational grazing should be putted into practice.