Earlier onset of the spring phytoplankton bloom in lakes of the temperate zone in a warmer climate
The decoupling of trophic interactions is potentially one of the most severe consequences of climate warming. In lakes and oceans the timing of phytoplankton blooms affects competition within the plankton community as well as food–web interactions with zooplankton and fish. Using Upper Lake Constance as an example, we present a model-based analysis that predicts that in a future warmer climate, the onset of the spring phytoplankton bloom will occur earlier in the year than it does at present. This is a result of the earlier occurrence of the transition from strong to weak vertical mixing in spring, and of the associated earlier onset of stratification. According to our simulations a shift in the timing of phytoplankton growth resulting from a consistently warmer climate will exceed that resulting from a single unusually warm year. The numerical simulations are complemented by a statistical analysis of long-term data from Upper Lake Constance which demonstrates that oligotrophication has a negligible effect on the timing of phytoplankton growth in spring and that an early onset of the spring phytoplankton bloom is associated with high air temperatures and low wind speeds.
Document Type: Research Article
Affiliations: 1: Limnological Institute, University of Konstanz, Mainaustrasse 252, D-78464 Konstanz, Germany, 2: Water Resources Department, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Überlandstrasse 133, CH-8600 Dübendorf, Switzerland
Publication date: 2007-09-01