Biomass and grazing potential of the <em>Stipa</em> loess steppes in Ningxia (northern China) in relation to grazing intensity

Abstract

The mere amount of biomass is not a suitable measuring unit for the economic value of a plant community, because not all species are equally appreciated by cattle and sheep and some are even unpalatable. That is why we summarised palatability and appreciation to a feeding value. Together with the biomass this feeding value was used to calculate the grazing potential of the plant communities investigated.
In the Stipa loess steppes of Ningxia (northern China) the two characteristic feather grasses dominating in ungrazed or slightly grazed areas are estimated as species of very high feeding value. Those species, which show increasing biomass parallel to increasing grazing intensity are of lower feeding value. Except of overgrazed areas, the Stipa grandis steppes have a higher grazing potential than the Stipa bungeana communities. A comparison of biomass and grazing potential shows that the relative differences between the grazing potential of the communities existing at different grazing levels are much higher than the relative differences in biomass.