Biodiversity loss decreases ecosystem functioning at the local scales at which species interact, but it remains unclear how biodiversity loss affects ecosystem functioning at the larger scales of space and time that are most relevant to biodiversity conservation and policy. Theory predicts that additional insurance effects of biodiversity on ecosystem functioning could emerge across time and space if species respond asynchronously to environmental variation and if species become increasingly dominant when and where they are most productive. Even if only a few dominant species maintain ecosystem functioning within a particular time and place, ecosystem functioning may be enhanced by many different species across many times and places (β-diversity). Here, we develop and apply a new approach to estimate these previously unquantified insurance effects of biodiversity on ecosystem functioning that arise due to species turnover across times and places. In a long-term (18-year) grassland plant diversity experiment, we find that total insurance effects are positive in sign and substantial in magnitude, amounting to 19% of the net biodiversity effect, mostly due to temporal insurance effects. Species loss can therefore reduce ecosystem functioning both locally and by eliminating species that would otherwise enhance ecosystem functioning across temporally fluctuating and spatially heterogeneous environments.
Bibliographical noteFunding Information:
We acknowledge funding support from the US National Science Foundation’s Long-Term Ecological Research (LTER)(DEB-1234162), Long-Term Research in Environmental Biology (DEB-1242531) and Ecosystem Sciences (NSF DEB-1120064) Programs, as well as the LTER Network Communications Office (DEB-1545288). ML was supported by the TULIP Laboratory of Excellence (ANR-10-LABX-41) and by the BIOSTASES Advanced Grant, funded by the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 666971). AG is supported by the Liber Ero Chair in Conservation Biology.
© 2018 John Wiley & Sons Ltd/CNRS
- complementarity effect
- ecosystem functioning
- insurance effect
- selection effect