Grassland containing a wide variety of plant types is more resistant to problems caused by climate change. Biomass production and ecosystem services can survive in conditions of average and even extreme draught or rainfall. Proof of this comes from a comparative study by an international team including researchers from Wageningen University, which has been published online by Nature on 14 October.
Up to now, proof that biodiversity can restrict the negative effects of climate change has not been convincing. Individual experiments carried out in grassland failed to produce unequivocal results, probably due to the degree and duration of the disruption to the climate. However, by linking the annual variations in biomass production from 46 multi-year experiments to all disruptions in the weather (wet, dry, average and extreme), a clear picture has emerged.
The study reveals that the positive effect of biodiversity lies in the resistance of a system, and not in its resilience. Resistance is the capacity to keep change through disruption to the minimum possible, whereas resilience refers to the speed with which an ecosystem returns to its previous level after disruption. “During climate disruption, production in grassland with more types of plant changes much less; for example, the grass yield suffers much less in periods of draught,” explains Jasper van Ruijven of Wageningen University. “However, the recovery of production one year after the disruption is not influenced by the extent of biodiversity.”
The conclusions reached by the study mean that the effects of climate change and the decline in biodiversity can reinforce each other, according to Van Ruijven. “One of the threats to biodiversity is climate change. At the same time, biodiversity serves to limit the effect of climate change. This means that climate change makes it additionally important to preserve biodiversity in order to maintain the productivity of an ecosystem and the ecosystem services that depend on this.”