Climatic extremes are expected to increase in magnitude and frequency. Especially, perennial plant communities of spatial and economic importance have to adapt to these changes. In Central Europe managed grasslands cover a large surface and contribute substantially to agricultural production. Here, we investigate four key grass species (Arrhenatherum elatius, Alopecurus pratensis Holcus lanatus , and Festuca pratensis).

Climatic envelopes are based on average climatic conditions and do not consider extremes. In order to evaluate future performance of grassland ecosystems, it is crucial to understand thresholds for population survival of key species. Furthermore, the climate envelope approach ignores the genetic variability within species.

We selected defined provenances of our target species across their European distribution and exposed these plants experimentally to extreme weather conditions (drought and heavy rain) in combination with and without warming.

Results/Conclusions

Our results show that there is a species specific response to climatic extremes. In addition, the variability of response differs between species indicating species-specific differences in phenotypic plasticity. Provenance effects confirm that southern and continental provenances cope better with drought.

We conclude that in order to maintain ecosystem functioning and stability in European grasslands the search for populations and provenances that are best adapted to the expected extremes is a very promising approach. The assisted migration and integration of genotypes within species, however, may mix local gene pools. Seeing important ecosystems at risk in face of climatic extremes, this disadvantage may be accepted if regime shifts and ecosystem breakdown can be avoided.