Phosphorus decrease and climate variability : mediators of synchrony in phytoplankton changes among European peri-alpine lakes

摘要: SUMMARY 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 monitoring programmes since the beginning of 1970s. Local management measures led synchronous declines phosphorus concentrations by more than 50% all four lakes. Their trophic state now ranges mesotrophic oligotrophic. 2. No coherence biomass was observed among lakes, or any significant decrease response (P)-reduction (oligotrophication), except Lakes Constance and Walen. 3. Multivariate analyses identified changes composition, which occurred coherently lakes despite differing absolute concentrations. 4. species benefiting oligotrophication mixotrophic and/or indicative oligo-mesotrophic conditions. 5. A major change at end 1980s. During this period there also a shift climatic conditions during winter early spring, suggesting impact factors. 6. Our results provide evidence geographically separated communities may occur even when overall are not synchronous.