Journal of Plant Ecology ›› 2017, Vol. 10 ›› Issue (1): 190-200.DOI: 10.1093/jpe/rtw109

所属专题: 生物多样性与生态系统功能

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Limited tree richness effects on herb layer composition, richness and productivity in experimental forest stands

Markus S. Germany1-3,*, Helge Bruelheide2,3 and Alexandra Erfmeier1,3   

  1. 1 Institute for Ecosystem Research, Geobotany, Kiel University, Olshausenstr. 75, 24118 Kiel, Germany; 2 Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06120 Halle, Germany; 3 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
  • 收稿日期:2015-09-30 接受日期:2016-10-08 出版日期:2017-02-04 发布日期:2017-01-30

Limited tree richness effects on herb layer composition, richness and productivity in experimental forest stands

Markus S. Germany1-3,*, Helge Bruelheide2,3 and Alexandra Erfmeier1,3   

  1. 1 Institute for Ecosystem Research, Geobotany, Kiel University, Olshausenstr. 75, 24118 Kiel, Germany; 2 Institute of Biology/Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06120 Halle, Germany; 3 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
  • Received:2015-09-30 Accepted:2016-10-08 Online:2017-02-04 Published:2017-01-30
  • Contact: Germany, Markus

摘要: Aims In forests, the herbaceous understory vegetation plays an important role for ecosystem functioning as it represents a significant component of total aboveground productivity. In addition, the herb layer contributes to overall forest species richness and controls tree species regeneration. Vice versa, trees in the overstory control understory herb and shrub growth through competition for resources. Using an experimental forest plantation with manipulated tree richness, we asked to which degree tree species richness and identity affect herb layer composition, richness and productivity and how these relationships across strata change with abiotic environmental conditions and competition intensity.
Methods In the context of the Biodiversity-Ecosystem Functioning project in subtropical China (BEF-China), we made use of the integrated BEFmod experiment arranged along a tree species richness gradient at two sites, with additional subplot treatments of phosphorus addition, herb layer weeding and no weeding. We recorded the understory vegetation and determined herb layer biomass production on a total of 201 subplots.
Important findings We found only minor effects of tree layer richness on herb layer species composition and no significant effect on herb layer richness or productivity yet. However, there were strong tree layer identity effects on all response variables, which were partly explained by differences in leaf area index and by a high share of woody species both in total herb layer species richness and biomass. There were strong treatment effects, which were largest in the 'no weeding' treatment but we did not find any treatment × tree layer richness interaction in herb layer responses. Thus, these effects are mainly explained by increased competition intensity within the herb layer in the absence of weeding. Despite the young age of the experiment, the interactions between tree species identity, tree richness and the herb layer did already emerge and can be expected to become stronger with ongoing runtime of the experiment.

Abstract: Aims In forests, the herbaceous understory vegetation plays an important role for ecosystem functioning as it represents a significant component of total aboveground productivity. In addition, the herb layer contributes to overall forest species richness and controls tree species regeneration. Vice versa, trees in the overstory control understory herb and shrub growth through competition for resources. Using an experimental forest plantation with manipulated tree richness, we asked to which degree tree species richness and identity affect herb layer composition, richness and productivity and how these relationships across strata change with abiotic environmental conditions and competition intensity.
Methods In the context of the Biodiversity-Ecosystem Functioning project in subtropical China (BEF-China), we made use of the integrated BEFmod experiment arranged along a tree species richness gradient at two sites, with additional subplot treatments of phosphorus addition, herb layer weeding and no weeding. We recorded the understory vegetation and determined herb layer biomass production on a total of 201 subplots.
Important findings We found only minor effects of tree layer richness on herb layer species composition and no significant effect on herb layer richness or productivity yet. However, there were strong tree layer identity effects on all response variables, which were partly explained by differences in leaf area index and by a high share of woody species both in total herb layer species richness and biomass. There were strong treatment effects, which were largest in the 'no weeding' treatment but we did not find any treatment × tree layer richness interaction in herb layer responses. Thus, these effects are mainly explained by increased competition intensity within the herb layer in the absence of weeding. Despite the young age of the experiment, the interactions between tree species identity, tree richness and the herb layer did already emerge and can be expected to become stronger with ongoing runtime of the experiment.

Key words: experimental research platform of BEF-China, functional biodiversity research, forest understory, biomass, Jiangxi Province