植物生态学报 ›› 2016, Vol. 40 ›› Issue (8): 735-747.DOI: 10.17521/cjpe.2015.0457

所属专题: 全球变化与生态系统

• 研究论文 •    下一篇

刈割、围封、放牧三种利用方式下草原生态系统的多功能性与植物物种多样性之间的关系

李静鹏, 郑志荣, 赵念席, 高玉葆*()   

  1. 南开大学生命科学学院, 天津 300071
  • 出版日期:2016-08-10 发布日期:2016-08-23
  • 通讯作者: 高玉葆
  • 基金资助:
    国家自然科学基金(31570427)

Relationship between ecosystem multifuntionality and species diversity in grassland ecosystems under land-use types of clipping, enclosure and grazing

Jing-Peng LI, Zhi-Rong ZHENG, Nian-Xi ZHAO, Yu-Bao GAO*()   

  1. College of Life Sciences, Nankai University, Tianjin 300071, China
  • Online:2016-08-10 Published:2016-08-23
  • Contact: Yu-Bao GAO

摘要:

随着全球变化对生物多样性的影响不断加剧, 生物多样性与生态系统功能之间相互关系(BEF)的研究显得极为重要。过去的20多年, BEF的研究大多集中在对物种多样性与单一或少数生态系统功能之间关系的探讨, 但生态系统最为重要的价值是同时维持多种服务和功能的能力, 基于此, 该文首次在国内引入近年来不断完善的生态系统多功能性(multifunctionality)的概念, 并对目前主流的评价方法进行了改进, 从而对内蒙古三种利用方式(刈割、围封、放牧)下的草地群落进行了多功能性评价, 并探讨了多功能性与物种多样性之间的关系。结果显示本研究改进的方法和目前主流方法评价得出的多功能性指数在样方和样地尺度上都有很高的相关性(R2 = 0.6956, p < 0.0001; R2 = 0.9231, p < 0.0001), 表明该文作者改进后的方法是可靠的。重度放牧的草地群落物种多样性水平最低, 绝大多数土壤功能指标较差, 表现出退化特征; 7年的围封和刈割群落均有较高的物种多样性水平和改善的土壤功能指标; 三者的多功能性指数为刈割(0.2178) >围封(0.0704) >放牧(-0.8031)。植被样方主要沿水肥梯度分布; 多样性指数中, 均匀度指数(Pielou index)和丰富度指数(Margelf index)对多功能性的影响作用最大, 均为样方尺度(R2 = 0.1871, p < 0.0001; R2 = 0.1601, p < 0.0001)小于样地尺度(R2 = 0.5921, p = 0.0093; R2 = 0.7499, p = 0.0007), 有尺度依赖性; 多功能性在样方和样地尺度上均与物种均匀度呈线性正相关关系, 而与物种丰富度呈单峰曲线关系。该文研究结果表明, 相对于重度放牧和围封, 刈割更有利于维持该地区生态系统的多功能性; 物种丰富度适中且物种分布均匀的生态系统可能有更好的多功能性。

关键词: 生物多样性与生态系统功能, 冗余分析, 多功能性, 物种多样性, 生态系统功能, 土地利用方式

Abstract:

Aims Over the past twenty years, most biodiversity and ecosystem functioning (BEF) research has focused on the effects of species diversity on single or just a few ecosystem functions. However, ecosystems are primarily valued for their ability to maintain multiple functions and services simultaneously (i.e. multifunctionality here- after). This paper first introduced the constantly perfected concept of “multifunctionality”, and then tried to make some modifications to the current mainstream quantitative method in order to evaluate the multifunctionality of grassland communities with the management of clipping, enclosure and grazing in Inner Mongolia, investigating the relationship between the multifunctionality and species diversity. Methods In free grazing grassland, four sites were set and each site was divided into two parts to conduct enclosure and clipping management respectively. After seven years, 15 quadrats (1 m × 1 m) were established for each type of management in each site (total 60 quadrats for each type) using the regular arrangement method; as a control, we also established 20 quadrats (two sites) in grazing grassland. For each quadrat, we carried out plants census and collected soil mixture sample, measuring 16 soil variables, and then calculated the biodiversity indices and multifunctionality index (M-index) by means of factor analysis. Important findings The results showed that M-indexes by the two evaluation methods were strongly correlated at both quadrat and site scale, suggesting that our modified method was reliable. Over-grazed communities had the lowest biodiversity indices and their most soil indicators were also low, showing obvious degradation features. Enclosure and clipping communities (seven years) had higher biodiversity and better soil indicators. The rank of M-indexes was clipping community (0.2178) > enclosure community (0.0704) > grazing community (-0.8031). The vegetation was distributed mainly along the gradients of water and fertility. Among the biodiversity indices, evenness (Pielou) index and richness (Margelf) index were most strongly correlated with multifunctionality, and their explanatory power (R2) for M-index were higher at site scale (R2 = 0.5921, p = 0.0093; R2 = 0.7499, p = 0.0007) than at quadrat scale (R2 = 0.1871, p < 0.0001; R2 = 0.1601, p < 0.0001), indicating study scale played an important role in the determinants of multifunctionality. At both quadrat and site scales, M-indexes is a linear positive function with species evenness and a hump-shaped function of species richness. Therefore, in contrast to enclosure, clipping was more conducive to maintain the ecosystem multifunctionality in this region, and the ecosystem with moderate specie richness, where these species are evenly distributed might have better multifunctionality.

Key words: biodiversity and ecosystem functioning (BEF), redundance analysis, multifunctionality, species diversity, ecosystem function, land-use types