植物生态学报 ›› 2012, Vol. 36 ›› Issue (12): 1248-1255.DOI: 10.3724/SP.J.1258.2012.01248

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

取样尺度对亚高寒草甸物种多样性与生产力关系的影响

袁自强, 魏盼盼, 高本强, 张荣*()   

  1. 兰州大学生命科学学院干旱农业生态研究所, 兰州 730000
  • 收稿日期:2012-08-09 接受日期:2012-10-07 出版日期:2012-08-09 发布日期:2012-11-28
  • 通讯作者: 张荣
  • 作者简介:(E-mail: rongz@lzu.edu.cn)

Effect of sampling scale on the relationship between species diversity and productivity in subalpine meadows

YUAN Zi-Qiang, WEI Pan-Pan, GAO Ben-Qiang, ZHANG Rong*()   

  1. Institute of Arid and Agro-ecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
  • Received:2012-08-09 Accepted:2012-10-07 Online:2012-08-09 Published:2012-11-28
  • Contact: ZHANG Rong

摘要:

植物物种多样性与生产力之间的关系是群落生态学的一个热点问题, 目前仍存在着很多争议。为探究自然群落中二者之间的关系, 对青藏高原亚高寒草甸3个样地的自然植物群落分别进行了不同取样面积的抽样调查。结果显示, 取样样地和取样尺度均对物种丰富度有显著影响, 取样样地而非取样尺度对群落地上生物量有显著性影响。在某一时刻对某一样地进行取样, 其单位面积生产力并不因取样面积的增加而提高, 而是保持恒定的, 尽管物种数随取样面积的增加而有明显增多。物种多样性与生产力之间的回归关系因样地与取样尺度不同而不同, 有U型、单峰型、正线性相关和无相关性, 其中无相关性出现的最多。据此推测, 亚高寒草甸群落物种多样性与生产力之间不存在某种确定性关系, 或者说, 亚高寒草甸物种多样性和生产力之间不存在必然的因果联系。

关键词: 群落生产力, 生态系统功能, 取样尺度, 物种多样性, 亚高寒草甸

Abstract:

Aims The relationship between species diversity and productivity has been a central issue in the face of increasing species extinctions; however, this issue has resulted in many disagreements. Our objectives were to determine (1) forms of the relationships between plant species diversity and productivity in natural communities in subalpine meadow and (2) effect of the sample area on the relationship between plant diversity and productivity. Methods We evaluated the relationships between species diversity and productivity by sampling three different study sites in subalpine meadow in the Hezuo region of Gansu Province, China in 2010. These three sites have different land use histories and altered vegetation traits. Sampling areas in each site were 0.01, 0.04, 0.16 and 0.64 m 2. The number of samples was 30 for each site. Sampling at each site was conducted randomly. In August 2010, we determined the aboveground, oven-dried biomass and the number of plant species in each sample quadrat. The relationship between species diversity and productivity was constructed by linearly and quadratically regressing both number of species and aboveground biomass. Important findings We found no significant relationship between number of species and aboveground biomass in two of the three sites, even though sampling areas were varied, and the relationship changed with sampling area in another experimental site that had been overgrazed. Both sampling area and study site had significant effects on number of species, while number of species in each sample increased with sampling area and aboveground biomass per unit area was constant, i.e., sampling areas had no effect on productivity. Variation of experimental site had a significant effect on aboveground biomass, and productivity of each site was not closely dependent on number of species but the site. Results suggest that there may be no fixed relationship between species diversity and productivity in natural communities of subalpine meadow.

Key words: community productivity, ecosystem functioning, sampling scale, species diversity, subalpine meadow