Chin J Plan Ecolo ›› 1996, Vol. 20 ›› Issue (5): 460-471.

• Research Articles • Previous Articles     Next Articles

Research on the Restoring Succession of the Degenerated Grassland in Inner Mongolia II. Analysis of the Restoring Processes

Wang Wei, Liu Zhong-ling, Hao Dun-yuan, Liang Cun-zhu   

  • Published:1996-05-10
  • Contact: Wang Ren-zhong

Abstract: The restoration dynamics of the Artemisia frigida community, one of the grazing-induced degenerated community of the zonal vegetation dominated by Leymus chinensis+Stipa grandis, was monitored after the fence during 1983 to 1995. The temporal data set were analysed. The results were as follows:1. Based on the replacement of dominant species and the result of principle component analysis, the process of restoring succession can be relatively divided into 4 stages, that is, the stage of degenerated community, the initial stage of restoration, the Agropyronmichnoi dominating stage, and the Leymus chinensis dominating stage.2. A feature of staircase transitions alternating with sub-atable treads is shown by change of community productivity during the restoring succession. The first transition started as soon as the grassland was fenced (in 1984), and the productivity level climbed to the first tread; the second transition was taken place in 1990, the productivity jumped second tread that approached the productivity of primary community.3. The relationship between community productivity and water resource were dependent on the stage of restoring succession. The standing crops of the community maintained the a standing crop of 166g·m-2 A precipitation favorable year with a rainfall of 176 mm during plant growth season had no significant effect to the raise of community productivity in the first sub-stable state stage. While the relationship between community biomass and precipitation was significant in the second sub-stable state stage. The water requirement for producing dry material were between 1.1~1.6mm·g-1,that is, the maximum water resource utilization ratio of community was 1.1mm·g-1,and the maximum production can be reached when the ratio was 1.6mm·g-14. The dots number of the studied community density is around 271.5 plants·m-2. The density became high and low alternatively and rhythmically, being the instinct mechanism of community restoration. The restoring succession speed could be measured by the half-change of communities. A 1.78 half-change. happened during the 10 years restoration.5. The restoration could be accelerated by adjusting grazing intensities and other techniques in accordance with the rhythmic regularity of the restoring succession.