Effects of a half a millennium winter on a deep lake – a shape of things to come?
Article first published online: 19 AUG 2010
© 2010 Blackwell Publishing Ltd
Global Change Biology
Volume 16, Issue 10, pages 2844–2856, October 2010
How to Cite
STRAILE, D., KERIMOGLU, O., PEETERS, F., JOCHIMSEN, M. C., KÜMMERLIN, R., RINKE, K. and ROTHHAUPT, K.-O. (2010), Effects of a half a millennium winter on a deep lake – a shape of things to come?. Global Change Biology, 16: 2844–2856. doi: 10.1111/j.1365-2486.2009.02158.x
- Issue published online: 1 SEP 2010
- Article first published online: 19 AUG 2010
- Received 18 August 2009; revised version received 23 November 2009 and accepted 25 November 2009
- climate change;
- Lake Constance;
- phytoplankton bloom;
- plankton succession;
- winter sequence
Analyses of the effects of extreme climate periods have been used as a tool to predict ecosystem functioning and processes in a warmer world. The winter half-year 2006/2007 (w06/07) has been extremely warm and was estimated to be a half-a-millennium event in central Europe. Here we analyse the consequences of w06/07 for the temperatures, mixing dynamics, phenologies and population developments of algae and daphnids (thereafter w06/07 limnology) in a deep central European lake and investigate to what extent analysis of w06/07 limnology can really be used as a predictive tool regarding future warming. Different approaches were used to put the observations during w06/07 into context: (1) a comparison of w06/07 limnology with long-term data, (2) a comparison of w06/07 limnology with that of the preceding year, and (3) modelling of temperature and mixing dynamics using numerical experiments. These analyses revealed that w06/07 limnology in Lake Constance was indeed very special as the lake did not mix below 60 m depth throughout winter. Because of this, anomalies of variables associated strongly with mixing behaviour, e.g., Schmidt stability and a measure for phosphorus upward mixing during winter exceeded several standard deviations the long-term mean of these variables. However, our modelling results suggest that this extreme hydrodynamical behaviour was only partially due to w06/07 meteorology per se, but depended also strongly on the large difference in air temperature to the previous cold winter which resulted in complete mixing and considerable cooling of the water column. Furthermore, modelling results demonstrated that with respect to absolute water temperatures, the model ‘w06/07’ most likely underestimates the increase in water temperature in a warmer world as one warm winter is not sufficient to rise water temperatures in a deep lake up to those expected under a future climate.