生物多样性 ›› 2007, Vol. 15 ›› Issue (3): 271-281.DOI: 10.1360/biodiv.060214

• 论文 • 上一篇    下一篇

干旱、半干旱区湖泊周围盐生植物群落的多样性格局及特点

杜泉滢1* ,李智2,3 ,刘书润4,刘鸿雁1   

  1. 1 (北京大学环境学院生态学系, 北京 100871)
    2 (北京大学深圳研究生院, 城市人居环境科学与技术重点实验室, 深圳 518055)
    3 (北京大学环境学院, 北京 100871)
    4 (内蒙古教育学院, 呼和浩特 010010)
  • 出版日期:2007-05-20 发布日期:2007-05-20

Dynamics of species diversity and characteristics of halophytic plant communities around saline lakes in arid and semi-arid regions of Inner Mongolia

Quanying Du1*, Zhi Li2,3, Shurun Liu4, Hongyan Liu1   

  1. 1 Department of Ecology, College of Environmental Sciences, Peking University, Beijing 100871
    2 The Key Laboratory for Environmental and Urban Sciences, Shenzhen Graudate School, Peking University, Shenzhen, Guangdong 518055
    3 College of Environmental Sciences, Peking University, Beijing 100871
    4 Inner Mongolia Education College, Huhhot 010010
  • Online:2007-05-20 Published:2007-05-20

摘要: 干旱、半干旱地区湖泊周围是盐渍化土壤的主要分布区,盐渍化是荒漠化的主要类型之一。目前,关于盐生植被的分布格局及群落多样性随着盐渍化程度加深的动态变化的研究仍很缺乏, 为阐释这种关系,作者在内蒙古干旱、半干旱地区选择吉兰泰(盐池)、乌梁素海、查干诺尔(碱矿)以及额吉诺尔(盐池)等4个湖泊,研究了其周围盐生植物群落的物种组成、分布特征以及群落结构的差异, 讨论了群落多样性沿盐分梯度的变化特点, 并在此基础上探讨了盐生植物群落对土壤盐分环境的指示意义。为建立群落耐盐值与群落多样性的关系,我们计算了群落耐盐值。结果表明, 盐生植物群落沿盐湖呈明显的环带状分布;随着土壤盐渍化程度的增加, 按照芨芨草群落(Comm. Achnatherum splendens)、盐爪爪群落(Comm. Kalidium foliatum)、盐角草群落(Comm. Salicornia europaea)和碱蓬群落(Comm. Suaeda glauca)的顺序演替, 而且物种种类趋向单一化, 群落结构趋向简单化。群落的物种多样性和群落间物种的替代速率都随土壤盐分的增加而减小, 而群落间物种的相似性则增加。区域性气候特点对盐生植物群落的特征也会产生一定的影响, 特别是在低盐渍化的条件下, 这种影响比较显著, 使得盐生植物群落体现出地带性的特点, 而随着土壤盐渍化程度的提高, 盐生植物群落的隐域性特征更为突出。因此, 这一地区的盐生植被又呈现出非常明显的地带性植被向非地带性植被过渡的特点。

AbstractSoil salinization is one of the main types of land desertification, which occurred widely around saline lakes in arid and semi-arid regions. Studies on the impact of salinization on the distribution and diversity of plant communities are still scarce. To explore the changes of halophytic vegetation along saline soil gradients, we collected halophyte samples around the lakes of Jartai, Ulansuhai Nur, Qagan Nur, and Ejin Nur, from desert, steppe-desert, desert-steppe, to typical grassland, representing a gradient of climate condi-tions. These plots also demonstrated a perfect salinity gradient both at a smaller scale (lake level) as well as at a larger scale (regional level). Using methodology of space-for-time substitution of halophytic plant communities as well as the extent of soil salinization, we analyzed the structure and distribution pattern of all communities. Based on 10 salinity gradients, salinity tolerance values of communities were calculated by mul-tiplying importance values and salt-tolerance values of each species. We also considered the significance of halophytic community as indicators of saline environments. The results showed that the halophyte communities are distributed around the lakes, accompanied with enrichment of community types and species number, from dry to wet climate zone. In particular, the communities were distributed following the sequence of Comm. Ach-natherum splendens, Comm. Kalidium foliatum, Comm. Salicornia europaea, Comm. Suaeda glauca, from margins to edges of lake banks and with the increase of salinity. On the other hand, species richness of the community declined from dry to wet climate zone due to appearance of similar species, and community struc-ture became simplified. As community salinity tolerance value increased, the α-diversity of all the communities decreased but at different rates. As for β-diversity, a more complex pattern appeared. We also found that the re-gional climatic conditions could influence halophytic community characteristics. Under conditions of slight salinization, the effects were more pronounced and the vegetation was characterized by a zonal vegetation. With the greater extent of salinization, the azonality character of the vegetation became more significant. These re-sults indicate that the halophytic vegetation in the study area was in a transition from zonal to azonal vegeta-tion.