Response of leaf structures of 8 plants to grazing prohibition in degraded grassland of Inner Mongolia
内蒙古退化草原8种植物叶结构对禁牧的响应

Representative communities of Artemisia frigida + Cleistogenes squarrosa which was the succession aberration of Leymus chinensis + Stipa grandis community were fenced in the Inner Mongolia typical steppe in 1983 and 1996 in order to observe the community succession processes.Eight predominant plants were collected from unfenced community(degenerated community),community fenced for 7 years and community fenced for 20 years.Leaf anatomical structures were compared to reveal the responses of plant leaf structures to grazing prohibition.It was showed: after fencing,the cuticle thickness,mesophyll cell density of leaves and leaf thickness of 5 species were lower than those before fencing,upper epidermis cells of Potentilla acaulis in community fenced for 20 years was smaller than those in degenerated community and in community fenced for 7 years,and the xerophytic characters of the leaves weakened.Plant leaves in degraded community did not fully reflect the xerophytic characters,or strengthened xerophytic characters.Based on the changes of leaf structures,it could be seen that tolerance to grazing in Potentilla acaulis was higher than those in the other species.Other indicators of leaf structure did not show the same trends.