Abstract: It is necessary to study on plant community condition and its succession in artificial sand-fixation plants in order to restore grassland productivity and maintain sustained and steady development of artificial vegetation community in Hulunbeir desertification grassland.The method adopted in this paper was to survey the artificial sand-fixing areas of Hulunbeir desertification grasslands with different recovery periods(1,3,4,and 5 years) and the important value,ecological volume,and niche overlap of main plant species were calculated.The results show that Agropyron pectinatum(Bieb.) Beauv.was the dominance species for the improvement of desertification grassland in this area and its average niche volume presented a continually increasing trend along with temporal scale.The niche overlap value was 0.9213 between Triticum aestivum L.and Caragana microphylla Lam.and 0.7512 between A.pectinatum and Hedysarum laeve Maxim indicating they had strong competitive capacities in community succession.But the niche overlap values between the nature resume plants and artificially seeded plants were not high.The gradual appearances of C1eistogenes squarrosa(Trin.) Keng and Stipa grandis P.Smirn.indicate the community of this area was stably developing to a coexisted artificial-natural state.

Key words: Hulunbeir, Artificial sand-fixation plants, Niche

摘要： 采用样方法对呼伦贝尔地区沙化草地不同恢复年限人工播种固沙区进行调查,并计算其主要植物的重要值、生态位体积及生态位重叠值,以研究呼伦贝尔沙化草地人工固沙植物群落特征及演替状况。结果表明:人工固沙植物冰草(Agropyron pectinatum(Bieb.)Beauv.)的平均生态位体积在时间尺度上,呈持续增加趋势,是改良沙化草地的优良草种;小麦(Triticum aestivum L.)与小叶锦鸡儿(Caragana microphylla Lam.)、冰草与羊柴(Hedysa-rum laeveMaxim)生态位重叠值为0.9213和0.7512,在演替过程中具较强的竞争作用。自然恢复植物与人工播种植物间,多数生态位重叠值不高。自然恢复多年生植物大针茅(Stipa grandis P.Smirn.)、糙隐子草(C1eistogenes squarrosa(Trin.)Keng)等逐渐出现,表明该地区植被群落结构向稳定共存的人工-天然植被群落结构方向发展。

关键词: 呼伦贝尔, 人工固沙植物, 生态位