Bram Vanschoenwinkel: “Our research has shown that it is not the number of species that is present in a specific grassland that determines whether it is a productive grassland or not, it is the number of species available in the region.
Biologists who study biodiversity-ecosystem functioning, or BEF, have been struggling with a problem for some time. BEF is the relationship between biodiversity, or the number of species per surface area, and the proper functioning of an ecosystem, with the major benefits being, for example, biomass production or CO2 sequestration.
Vanschoenwinkel: “You would expect that high biodiversity would lead to a well-functioning ecosystem, but that is not always the case. Sometimes low biodiversity does not have a negative effect on the functioning of the ecosystem. In other words, you can have a grassland that produces a lot of biomass with many or with few species.”
Scale does matter
Vanschoenwinkel and fellow researchers James Hagan and Lars Gamfeldt have now been able to find out why for the first time. In their research, recently published in the leading journal Ecology Letters, they showed that local biodiversity is no guarantee for high functionality of the ecosystem, for example in terms of productivity.
Vanschoenwinkel: “At first sight, this seems to be a worrying result, because it suggests that biodiversity is not that important at all. But the opposite appears to be the case. Biodiversity remains important, but on a larger spatial scale.
The researchers have shown that it is not the biodiversity of the local grassland itself but that of the wider environment that is crucial for productivity.
Vanschoenwinkel: “And this is exactly what our ecosystems need: the largest possible natural reserve of species in our landscapes that can respond to what we will face in the future.”
For their evidence, they used mathematical models and long-term datasets to investigate the link between biodiversity and productivity of grasslands and other ecosystems.
Vanschoenwinkel: “At the moment, the research focuses on the link between biodiversity and productivity, but it will be interesting to look at the exact relationships between biodiversity and other ecosystem services, such as the purifying effects of ecosystems on our environmental quality and positive effects on human psychology.”
James Hagan holds an MSc in biology from VUB and is a PhD student at the University of Gothenburg under the promotership of Lars Gamfeldt and Bram Vanschoenwinkel, senior lecturer in ecology at VUB who leads the Community Ecology Lab.