Climate change shifts grass phenology

The flowering time of grass species can be adjusted according to climate, but will it be enough to cope with warmer climates of the future?

GBIF-mediated data resources used : 5,719 species occurrences
Iodine bush (Allenrolfea occidentalis)

Iodine bush (Allenrolfea occidentalis) by James Bailey. Licensed under CC BY-NC 4.0.

In this study, researchers used herbarium records from GBIF and other sources to investigate how well grasses of the western United States cope with environmental variability.

Deriving flowering date of each grass species from the specimen collection date and relating this to climate data, the researchers found that increasing temperature variables affected flowering time differently according to photosynthetic pathway, as flowering was accelerated in C3 plants, but delayed in C4. For precipitation, increasing variable values generally delayed flowering. In both cases, however, the behaviour also depended on the ecoregion of the grass species, most likely attributable to species adaptation to local climates.

The results confirm that grass flowering time is largely controlled by climate change, and that grass phenology can cope with moderate changes in temperature and precipitation. This resilience, however, is most relevant if species can migrate to new locations, which is unlikely to happen at the same velocity of climate change.

Munson SM and Long AL (2016) Climate drives shifts in grass reproductive phenology across the western USA. New Phytologist. Wiley-Blackwell 213(4): 1945–1955. Available at: