植物生态学报 ›› 2008, Vol. 32 ›› Issue (5): 1157-1165.DOI: 10.3773/j.issn.1005-264x.2008.05.020

所属专题: 青藏高原植物生态学:群落生态学

• 研究论文 • 上一篇    下一篇

青藏高原“黑土滩”次生毒杂草群落成体植株与幼苗空间异质性及相似性分析

尚占环1, 龙瑞军1,*(), 马玉寿2, 丁路明3   

  1. 1 兰州大学青藏高原生态系统管理国际中心, 草地农业科技学院,兰州 730020
    2 青海省畜牧兽医科学院草原研究所,西宁 800016
    3 干旱与草地生态教育部重点实验室, 兰州大学,兰州 730000
  • 收稿日期:2007-06-18 接受日期:2008-04-15 出版日期:2008-06-18 发布日期:2008-09-30
  • 通讯作者: 龙瑞军
  • 作者简介:*(longrj@lzu.edu.cn)
  • 基金资助:
    国家自然科学基金(30600426);国家自然科学基金(30370069)

SPATIAL HETEROGENEITY AND SIMILARITY OF ADULT PLANTS AND SEEDLINGS IN ‘BLACK SOIL LAND’ SECONDARY WEED COMMUNITY, QINGHAI-TIBETAN PLATEAU

SHANG Zhan-Huan1, LONG Rui-Jun1,*(), MA Yu-Shou2, DING Lu-Ming3   

  1. 1International Centre for Tibetan Plateau Ecosystem Management, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
    2Institute of Grassland Science, Qinghai Academy of Animal and Veterinary Science, Xining 810016, China
    3Key Laboratory of Arid and Grassland Agroecology of Education Ministry, Lanzhou University, Lanzhou 730000, China
  • Received:2007-06-18 Accepted:2008-04-15 Online:2008-06-18 Published:2008-09-30
  • Contact: LONG Rui-Jun

摘要:

在样线调查基础上, 用半方差函数、分形维数、空间自相关等方法对青藏高原“黑土滩”次生毒杂草群落地上成体植株、幼苗空间的异质性, 二者物种构成的相似性及其尺度特征进行分析。结果表明, “黑土滩”次生毒杂草群落在较大尺度上地上成体植株物种数的空间依赖性强, 异质性高, 而个体密度则较均匀; 幼苗物种数在小尺度上空间异质性高, 幼苗密度在大尺度上空间异质性较高, 幼苗密度独立于其物种分布, 高密度的幼苗分布在微地形下和群落间隙中, “黑土滩”毒杂草植物幼苗充分利用空余生态位进行群落补充; “黑土滩”群落在不同尺度上地上成体植株与幼苗物种构成相似性变化的规律性不大; “黑土滩”群落幼苗靠其高密度特征完成群落更新, 植物群落幼苗更新力强, 导致“黑土滩”毒杂草群落趋于稳定。因此, 建议加强干扰以减弱“黑土滩”次生毒杂草群落稳定趋势, 这对恢复“黑土滩”具有重要指导意义。

关键词: 青藏高原, “黑土滩”退化草地, 毒杂草, 幼苗, 空间异质性, 群落更新

Abstract:

Aims ‘Black soil land’ grassland on the Tibetan Plateau results from degradation of Kobresia alpine meadow and has many weeds and poisonous plants. This disturbed grassland forms in small bottomland patches. There are no studies of community spatial patterns, relationships and scale patterns of adult plants and seedlings are important to explaining the formation of this secondary weed community.

Methods We selected a typical ‘black soil land’ community of about 30 m × 50 m in the headwaters of the Yellow River and used 100 sample plots (50 cm × 50 cm) to investigate number and density of adults and seedlings (determined by pulling) by species. Spatial heterogeneity of the community and the similarity between adult plants and seedlings were analyzed by semi-variance, fractal dimension, spatial correlation spatial autocorrelation, etc.

Important findings Species number of adult plants is highly spatially heterogeneous and plant density homogeneous at large scales. Species number of seedlings is highly spatially heterogeneous at small scales, and its density is highly spatially heterogeneous at large scales. Seedlings have high density in areas of micro-topography and gaps of adult plants, where seedlings grow and establish in empty ecological niches. The ‘black soil land’ community regenerates and recruits in vegetation gaps. The generation of ‘black soil land’ community depends on high density of seedlings of weeds and poisonous plants, and its generation capability is strong. According to our results, the ‘black soil land’ secondary community becomes more stable without interference. We suggest that human management be used to decrease the stability of the ‘black soil land’ weed community and restore alpine meadow.

Key words: Qinghai-Tibetan Plateau, ‘black soil land’ degraded grassland, weed and poisonous plant, seedling, spatial heterogeneity, community regeneration