A substantial body of evidence has demonstrated that biodiversity stabilizes ecosystem functioning over time in grassland ecosystems. However, the relative importance of different facets of biodiversity underlying the diversity–stability relationship remains unclear. Here we use data from 39 grassland biodiversity experiments and structural equation modelling to investigate the roles of species richness, phylogenetic diversity and both the diversity and community-weighted mean of functional traits representing the ‘fast–slow’ leaf economics spectrum in driving the diversity–stability relationship. We found that high species richness and phylogenetic diversity stabilize biomass production via enhanced asynchrony in the performance of co-occurring species. Contrary to expectations, low phylogenetic diversity enhances ecosystem stability directly, albeit weakly. While the diversity of fast–slow functional traits has a weak effect on ecosystem stability, communities dominated by slow species enhance ecosystem stability by increasing mean biomass production relative to the standard deviation of biomass over time. Our in-depth, integrative assessment of factors influencing the diversity–stability relationship demonstrates a more multicausal relationship than has been previously acknowledged.
Bibliographical noteFunding Information:
This paper is a product of the sTability group funded by sDiv (www.idiv.de/stability), the Synthesis Centre of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig (DFG FZT 118). The Jena Experiment is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation; FOR 1451) and the Swiss National Science Foundation. The Cedar Creek biodiversity experiments were supported by awards from the Andrew Mellon Foundation, the US National Science Foundation (NSF) Long-Term Ecological Research (grant numbers DEB-9411972, DEB-0080382, DEB-0620652 and DEB-1234162), Biocomplexity Coupled Biogeochemical Cycles (DEB-0322057), Long-Term Research in Environmental Biology (DEB-0716587, DEB-1242531) and Ecosystem Sciences (NSF DEB-1120064) Programs, as well as the US Department of Energy Programs for Ecosystem Research (DE-FG02-96ER62291) and National Institute for Climatic Change Research (DE-FC02-06ER64158). The Texas MEND study was funded by US-NSF DEB-0639417 and USDA-NIFA-2014-67003-22067. The study has been supported by the TRY initiative on plant traits (http://www.try-db. org). TRY is currently supported by DIVERSITAS/Future Earth and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig. V.O. received financial support from the Russian Science Foundation (14-50-00029). The authors would also like to thank J. Lefcheck for his help in revising the structural equation models.
© 2018, The Author(s).