A large body of research shows that biodiversity loss can reduce ecosystem functioning. However, much of the evidence for this relationship is drawn from biodiversity–ecosystem functioning experiments in which biodiversity loss is simulated by randomly assembling communities of varying species diversity, and ecosystem functions are measured. This random assembly has led some ecologists to question the relevance of biodiversity experiments to real-world ecosystems, where community assembly or disassembly may be non-random and influenced by external drivers, such as climate, soil conditions or land use. Here, we compare data from real-world grassland plant communities with data from two of the largest and longest-running grassland biodiversity experiments (the Jena Experiment in Germany and BioDIV in the United States) in terms of their taxonomic, functional and phylogenetic diversity and functional-trait composition. We found that plant communities of biodiversity experiments cover almost all of the multivariate variation of the real-world communities, while also containing community types that are not currently observed in the real world. Moreover, they have greater variance in their compositional features than their real-world counterparts. We then re-analysed a subset of experimental data that included only ecologically realistic communities (that is, those comparable to real-world communities). For 10 out of 12 biodiversity–ecosystem functioning relationships, biodiversity effects did not differ significantly between the full dataset of biodiversity experiments and the ecologically realistic subset of experimental communities. Although we do not provide direct evidence for strong or consistent biodiversity–ecosystem functioning relationships in real-world communities, our results demonstrate that the results of biodiversity experiments are largely insensitive to the exclusion of unrealistic communities and that the conclusions drawn from biodiversity experiments are generally robust.
Bibliographical noteFunding Information:
We thank the establishers, maintainers, coordinators, technical and research staff, and data owners of all involved projects, as well as the TRY initiative. We thank S. Soliveres and E. Allan for discussion; S. Thiel, G. Luo, D. Bahauddin and F. Schneider for help with data extraction and handling; and R. Junker and B. Blonder for assistance with the calculation of multidimensional hypervolumes. This study was funded through Jena Experiment SP 7 (Swiss National Science Foundation grant no. 310030E-166017/1). Further support came from the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, funded by the German Research Foundation (grant no. FZT 118). The Jena Experiment was funded by the Deutsche Forschungsgemeinschaft (grant nos FOR 456 and FOR 1451) with additional support from Friedrich Schiller University Jena, the Max Planck Institute for Biogeochemistry in Jena and the Swiss National Science Foundation. All Cedar Creek studies are funded by the US National Science Foundation’s Long-Term Ecological Research (LTER) programme (grant no. DEB-1234162). F.I. acknowledges funding from the LTER Network Communications Office (grant no. DEB-1545288). We thank the iDiv Data Repository for hosting our R code and aggregated datasets and for performing the related quality checks.
© 2020, The Author(s), under exclusive licence to Springer Nature Limited.
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.