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草业学报 ›› 2012, Vol. 21 ›› Issue (5): 23-31.

• 研究论文 • 上一篇    下一篇

封育三年对三种高寒草地群落土壤种子库的影响

邓斌1,任国华1,刘志云1,尚占环1,2*,裴世芳1   

  1. 1.兰州大学青藏高原生态系统管理国际中心 草地农业生态系统国家重点实验室 草地农业科技学院,甘肃 兰州 730020;
    2.中国科学院青藏高原研究所,北京 100101
  • 收稿日期:2011-05-16 出版日期:2012-05-25 发布日期:2012-10-20
  • 通讯作者: E-mail:shangzhh@lzu.edu.cn
  • 作者简介:邓斌(1986-),男,湖南衡阳人,在读硕士。E-mail:dengbin1234567@qq.com
  • 基金资助:
    国家自然基金(No. 41171417; 30600426;30730069)和中央高校基本科研业务费专项资金(lzujbky-2010-8)资助。

Effect of 3-year fencing on soil seed banks of three alpine grassland communities

DENG Bin1, REN Guo-hua1, LIU Zhi-yun1, SHANG Zhang-huan1,2, PEI Shi-fang1   

  1. 1.International Centre for Tibetan Plateau Ecosystem Management, State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China;
    2.Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China
  • Received:2011-05-16 Online:2012-05-25 Published:2012-10-20

摘要: 选择青藏高原黄河源区封育三年的灌丛草地、小嵩草退化草地和黑土滩等3个高寒草地群落为研究对象,利用镜检法,对其土壤种子库的规模、物种组成、空间分布及与地上植被的相关性进行研究。结果表明,1)小嵩草退化草地、黑土滩、灌丛草地围栏内外土壤种子库密度分别为(9 938±1 780)粒/m2和(15 330±1 827)粒/m2、(4 074±459)粒/m2和(3 640±486)粒/m2、(9 879±1 453)粒/m2和(12 899±1 695)粒/m2,且只有小嵩草退化草地围栏内外表现出差异显著。2)3种高寒草地群落围栏内外土壤种子库物种数目差异不显著,但禾本科与莎草科种子在土壤种子库中所占的比例表现为围栏内>围栏外,草地围栏能提高原生植被土壤种子库比例。3)各样地的土壤种子库的Shannon-Wiener多样性指数、Simpson多样性指数和Pielou均匀度指数有着相同的变化规律:黑土滩>灌丛草地>小嵩草退化草地;Margalef丰富度规律为:小嵩草退化草地>黑土滩>灌丛草地。3种高寒草地群落土壤种子库与地上植被的Sorensen相似性指数大小范围为0.32~0.64,变化为:黑土滩>小嵩草退化草地>灌丛草地,围栏内>围栏外。4)土壤种子库主要集中在0~5 cm土层中,平均占土壤种子库的比例为88.56%。黑土滩群落围栏内外5~10 cm层土壤种子库种子数所占的比例要显著大于灌丛草地与小嵩草退化草地。围栏封育能够提高退化高寒草地土壤种子库数量,对退化草地的恢复有重要作用。

Abstract: In the Yellow River source region of the Qinghai-Tibet Plateau, we selected three different alpine grassland communities (shrub grassland, Kobresia pygmaea degraded grassland and black-soil) through three years of enclosure. Microscopic examination was used to research the size of soil seed banks, species composition, spatial distribution and correlation between vegetation and soil seed banks. The results showed that: 1) The density of soil seed banks within and outside the fence of K. pygmaea degraded grassland, black-soil and shrub grassland respectively were (9 938±1 780) and (15 330±1 827) seeds/m2, (4 074±459) and (3 640±486) seeds/m2, and (9 879±1 453) and (12 899±1 695) seeds/m2, respectively but only the K. pygmaea degraded grassland within and outside the fence had significant differences. 2) The number of species in soil seed banks in the three alpine grassland communities within and outside the fence was not significantly different, but the proportion of grass and sedge seeds in the soil seed banks were greater within than outside the grassland fence which increased the proportion of native vegetation in the soil seed bank. 3) The Shannon-Wiener diversity index, Simpson diversity index and Pielou evenness index of the soil seed banks had the same pattern in each community and: black-soil>shrub grassland>K. pygmaea degraded grassland: K. pygmaea degraded grassland>black-soil>shrub grassland by the Margalef richness rules. The range of Sorensen similarity index between soil seed banks and vegetation in the three alpine grassland communities was 0.32-0.64 in the sequence and black-soil>K. pygmaea degraded grassland>shrub grassland, and within>outside. 4) Soil seed banks were mainly in the 0-5 cm soil layer with an average proportion of 88.56% of the total soil seed bank. While the overall differences within and outside the fence of the three grassland communities were not significant, the proportion of black-soil soil seed numbesr in the 5-10 cm layer was significantly greater than those of the shrub grassland and K. ygmaea degraded grassland. Thus grassland enclosure improved grassland soil seed bank status, had a greater significant effect for degraded grassland, and played an important role in grassland maintainance and recovery.

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