Study on Ecological Restoration Technique of Degraded Grassland by Enclosing Experiment in the Ecotone between Agriculture and Pasture in Northern China

The ecotone between agriculture and pasture in Keshiketeng,by taking the different degree of degraded grassland(mild degraded grassland,moderate degraded grassland,specific weight degraded grassland) as the place of samples,and by the comparison of non-enclosed grassland,the restored condition of the structure of grass group composition,the vegetation height and output for each kind of degraded grassland are discussed.The result indicats that after enclosing the vegetation of the mild degraded grassland the restoration may be obtained in a shorter time;the restoration for moderate degraded grassland needs longer time,generally 5 years;and the specific weight degraded grassland have reduced in backlash degree in enclosing five years.