SS3.06 Large Scale Change in Prominent Ecosystems
Date: Wednesday, June 12, 2002
Time: 11:15:00 AM
Location: Lecture Theatre
 
AnnevilleO, Universität Konstanz, Konstanz, Germany, Orlane.Anneville@uni-konstanz.de
Gammeter, S, , Zurich Water Supply, Zurich, Switzerland, Sonja.Gammeter@wvz.stzh.ch
Kümmerlin, R, , Institut für Seenforschung, Langenargen, Germany, reiner.kuemmerlin@lfula.lfu.bwl.de
Straile, D, , Universität Konstanz, Konstanz, Germany, Dietmar.Straile@uni-konstanz.de
 
LAKES IN THE LANDSCAPE: LARGE-SCALE METEOROLOGICAL FORCING AND CHANGES IN TROPHIC STATUS INFLUENCE PHYTOPLANKTON TEMPORAL COHERENCE BETWEEN DEEP PREALPINE LAKES
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Extensive data sets of physical, chemical and plankton parameters, each covering more than 20 years, have been gathered for comparative analyses of long-term changes in phytoplankton composition of four neighbouring deep prealpine European lakes (Lakes Geneva, Constance, Zurich and Walen). These lakes share a common history of eutrophication and subsequent oligotrophication during the last century. In addition, all four lakes are close enough to experience rather similar interannual differences in weather patterns associated with interannual variability of the North Atlantic Oscillation (NAO). We show that the impact of the NAO resulted into coherence in water temperatures, but also in chemical and biological variables within the four lakes. Coherence due to the NAO was strongest during spring and decreased after the clear-water phase, while the impact of trophic changes on phytoplankton populations was most important during summer.