Abstract: In the Loess hilly regions,different vegetation deployment modes were fixed along the slopes in order to close the hillsides for restoring vegetation and afforestation.Prunus davidiana or Caragana korshinskii + Stipa bungeana+ Achanatcherum splendens were planted in the upper slopes; Caragana korshinskii or Hippophae rhamnoides + Stipa bungeana+ Achanatcherum splendens in the mid-slopes;and Hippophae rhamnoides or Caragana korshinskii+ Achanatcherum splendens in the down-slopes.Through more than 20 years'observation and research,it is revealed that significant differences appeared in the community structure and population type between the cultivated shrubbery and grasslands,and the natural grasslands.The cultivated shrubbery and grasslands thrived,and the community took on clockwise succession with Stipa bungeana population dominating by seed and root turions germination.The process of succession could be divided into 4 stages: the initial bleak,scanty grassland(1 year)→weedy and stubbly grassland(2-3 years)→Stipa bungeana population luxuriating,while weeds and poisonous plants reducing and exterminated(4-5 years)→stable development of Stipa bungeana population(6-8 years).

Key words: Loess hilly regions, Vegetation restoration, Succession process, Population dynamics

摘要： 在黄土丘陵区,采用封育与重建相结合的方法,按不同坡位建立植被类型配置模式,即坡上部为山桃(Prunus davidiana)或柠条(Caragana korshinskii)+本氏针茅(Stipa bungeana)+芨芨草(Achanatcherum splendens);坡中部为柠条或沙棘(Hippophae rhamnoides)+本氏针茅+芨芨草;坡下部为沙棘或柠条+芨芨草。20多年的定位观测研究表明:人工灌木林、人工草地和天然草地的植物群落结构及种群类型变化差异显著;封育天然草地本氏针茅种群通过种子和根蘖繁殖已占据优势,其演替过程一般分为4个阶段,即荒山荒坡草地(1年)→杂草群聚生长(2-3年)→本氏针茅种群大量出现,杂草和有毒有害植物大幅度消减,(4-5年)→本氏针茅种群稳定阶段(6-8年)。

关键词: 黄土丘陵区, 植被恢复, 植被演替, 种群动态