Vegetation restoration by seasonal exclosure in the Kerqin Sandy Land, Inner Mongolia

Grazing control has been reported to be effective for the control of desert ification in semi-arid regions. However, economic reasons often make comple te inhibition of grazing (complete exclosure) difficult to carry out. Grazi ng control has been applied to the Kerqin Sandy Lands, Inner Mongolia, Chin a, by means of seasonal exclosure, whereby grazing is allowed from November to Apt-ii. The harvesting of hay is also allowed once during September - O ctober. The aim of the reported study was to evaluate the effectiveness of this seasonal exclosure on vegetation restoration. Species compositional da ta were obtained from 356 quadrats and ordinated by Detrended Correspondenc e Analysis (DCA). Ordination indicated that landform was the most important factor influencing the species composition of the vegetation. Regardless o f landform and type of grazing control, however, vegetation coverage, veget ation height and species richness were higher at sites where grazing had be en controlled, than at sites lacking any control. Perennial species were do minant at the former while annual species were dominant at the latter. Both shrub and toe species were quits rare at the sites where seasonal exclosur e had been carried out. It is concluded that seasonal exclosure is sufficie nt to restore and maintain grassland vegetation in and around the study are a. When shrubby or tree vegetation is needed for reasons such as fixing san ds or preventing sand dune remobilization, complete exclosure is recommende d.