Meteorological forcing of plankton dynamics in a large and deep continental European lake

Abstract

The timing of various plankton successional events in Lake Constance was tightly coupled to a largescale meteorological phenomenon, the North Atlantic Oscillation (NAO). A causal chain of meteorological, hydrological, and ecological processes connected the NAO as well as winter and early spring meteorological conditions to planktonic events in summer leading to a remarkable memory of climatic effects lasting over almost half a year. The response of Daphnia to meteorological forcing was most probably a direct effect of altered water temperatures on daphnid growth and was not mediated by changes in phytoplankton concentrations. High spring water temperatures during "high-NAO years" enabled high population growth rates, resulting in a high daphnid biomass as early as May. Hence, a critical Daphnia biomass to suppress phytoplankton was reached earlier in high-NAO years yielding an early and longerlasting clear-water phase. Finally, an earlier summer decline of Daphnia produced in a negative relationship between Daphnia biomass in July and the NAO. Meteorological forcing of the seasonal plankton dynamics in Lake Constance included simple temporal shifts of processes and successional events, but also complex changes in the relative importance of different mechanisms. Since Daphnia plays an important role in plankton succession, a thorough understanding of the regulation of its population dynamics provides the key for predictions of the response of freshwater planktonic food webs to global climate change.

Asynchrony of spring phytoplankton response to temperature driver within a spatial heterogeneity bay of Three-Gorges Reservoir, China

“…Most previous studies often regarded the development of spring phytoplankton spring as a period cycle of seasonal events and emphasized the importance of large-scale climatic fluctuation on the development of spring bloom (Semetacek, 1990;Yin et al, 1997;Straile, 2000;Iriarte and Purdie, 2004;Miller and Harding, 2007). Some studies have confirmed the expected earlier onset of the spring bloom under warming conditions (Rees et al, 1999;Peeters et al, 2007a), which agree with the frequently reported earlier onset of spring events reported from terrestrial ecosystems (e.g.…”

An indoor mesocosm system to study the effect of climate change on the late winter and spring succession of Baltic Sea phyto- and zooplankton

“…Madhudatrap et al (1996) triggered the germination of six Baltic Sea zooplankton species (four copepods, two cladocerans) by temperature increase in the laboratory. The temperature dependence of zooplankton spring growth must have consequences for the timing and extent of the clear-water phase, as predicted by a recent model for Lake Constance (Scheffer et al 2001) and by an analysis of field data using the present day climate variability (Straile 2000).…”

“…Climate change is already affecting a wide variety of ecosystems (Walther et al 2002), including aquatic ones (Edwards et al 2002;Edwards and Richardson 2004;Fromentin and Planque 1996;Straile 2000;Straile and Adrian 2000), and will increasingly continue to do so if the prevailing predictions of further greenhouse warming are fulfilled. Already, now, the Baltic Sea is characterised by a strong geographic, seasonal, and interannual variability of all relevant hydrographic variables, which are closely connected to the atmospheric forcing in the region (Matthä us and Schinke 1994; Lehmann et al 2002).…”

“…The succession patterns observed in our experiments differ considerably from the freshwater ones dominated by the zooplankton genus Daphnia spp., analysed in a comparative field study (Straile 2000) and in a model study (Scheffer et al 2001). In the Daphnia systems seasonal succession starts with close-to-zero levels of both phyto-and zooplankton.…”

Using the NOAA Advanced Very High Resolution Radiometer to characterise temporal and spatial trends in water temperature of large European lakes

“…For example, European lake ecosystems are influenced by variations in the North Atlantic Oscillation (e.g. Gerten & Adrian, 2000Livingstone & Dokulil, 2001;Straile, 2000;Straile & Adrian, 2000;Weynhenmeyer et al, 1999Weynhenmeyer et al, , 2002. In addition, lakes have the potential to reveal changes and homogeneous trends even at relatively short (i.e.…”