关键词: 内蒙古典型草原, 放牧率, 牧草繁殖特性, 退化机制, 微生物社会学, 公共物质, 种群稳定, 细菌交流, 社会进化

Abstract: The experiment was conducted on the degraded grassland in Inner Mongolia dominated by Artemisia frigida and short grasses with given stocking rates for 6 years, to study the morphological responses of 9 major plant populations to grazing. The results show that the grasses with different life types and vegetative reproduction properties differed in responding strategies to stocking rates, which formed the basis for community succession at different stocking rates. The herbage with vegetative reproduction by stolons or of higher tillering, such as Artemisia frigida and Potentilla acaulis, were suitable for heavy grazing. Leymus chinense and Agropyron cristatum which are vegetative reproduction by rhizomes and tillering and Stipa krylovii were suitable for light grazing. Carex duriuscula with vegetative reproduction by rhizomes and tillering and Cleistogenes squarrosa were suitable for medium grazing. Melissitus ruthenica and Kochia prostata with branching reproduction were suitable for light grazing. The community composition changed with increasing stocking rate, and the proportion of short grasses in community gradually decreased. Consequently, the degraded grassland dominated by Artemisia frigida and short grasses ultimately converged to the degraded grassland dominated by Potentilla acaulis. Light grazing could maintain the existing state of grassland, or make it retrograde by increasing the proportion of grasses, which achieved the goal of utility typed improvement.

Key words: Inner Mongolia steppe, Stocking rate, Reproductive characteristics of forage grass, Degradation mechanism, socio-microbiology, bacterial communication, social evolution, public goods, stabilization of population