IAS-SIGMOID

Will plants flower earlier and earlier with increasing temperature?

Detection of nonlinearities in temperature responses in phenology using European time series

Phenology has attracted increasing interest in recent years. Air temperature is the most important factor influencing plant phenology; thus, recent warming has considerable effects on onset dates of recurring natural events such as flowering or leaf unfolding.

One nearly linear relationship seems to have been stable for long: The higher the temperature, the earlier the phenological onset date. However, new questions emerge when extrapolating this obviously robust statistical relationship outside the present temperature range: Will plants flower earlier and earlier with increasing temperatures? Or is there a specific limit, an absolute minimum onset date, even with still higher temperatures? If yes, only temperature based linear models cannot adequately predict phenological onset dates in a warmer climate.

To describe future impacts on phenology, it is crucial to determine those nonlinearities in temperature responses. Thus, we analyse long-term European data records (PEP725) within the project IAS-SIGMOID in detail. Nonlinearities might be especially encountered at the southern extreme of a plant’s natural distribution.

Contact person:

Dr. Susanne Jochner

Duration:

01.02.2013-31.05.2013