Present address: Sonja Gammeter, PO Box 1279, Midland WA 6936, Australia.
Phosphorus decrease and climate variability: mediators of synchrony in phytoplankton changes among European peri-alpine lakes
Article first published online: 1 SEP 2005
Volume 50, Issue 10, pages 1731–1746, October 2005
How to Cite
ANNEVILLE, O., GAMMETER, S. and STRAILE, D. (2005), Phosphorus decrease and climate variability: mediators of synchrony in phytoplankton changes among European peri-alpine lakes. Freshwater Biology, 50: 1731–1746. doi: 10.1111/j.1365-2427.2005.01429.x
- Issue published online: 1 SEP 2005
- Article first published online: 1 SEP 2005
- (Manuscript accepted 20 March 2005)
- long-term changes;
- multivariate analyses;
- phytoplankton community;
- temporal coherence
1. In an attempt to discern long-term regional patterns in phytoplankton community composition we analysed data from five deep peri-alpine lake basins that have been included in long-term monitoring programmes since the beginning of the 1970s. Local management measures have led to synchronous declines in phosphorus concentrations by more than 50% in all four lakes. Their trophic state now ranges from mesotrophic to oligotrophic.
2. No coherence in phytoplankton biomass was observed among lakes, or any significant decrease in response to phosphorus (P)-reduction (oligotrophication), except in Lakes Constance and Walen.
3. Multivariate analyses identified long-term changes in phytoplankton composition, which occurred coherently in all lakes despite the differing absolute phosphorus concentrations.
4. In all lakes, the phytoplankton species benefiting from oligotrophication included mixotrophic species and/or species indicative of oligo-mesotrophic conditions.
5. A major change in community composition occurred in all lakes at the end of the 1980s. During this period there was also a major shift in climatic conditions during winter and early spring, suggesting an impact of climatic factors.
6. Our results provide evidence that synchronous long-term changes in geographically separated phytoplankton communities may occur even when overall biomass changes are not synchronous.