Copepods play a crucial role in the food webs and biogeochemical fluxes in marine and freshwater environments. Copepods have been shown to respond to climate variability in a variety of studies and do have a complex life cycle including diapause, several developmental stages, and a major metamorphosis from the nauplii to the copepod stage. The timing of these life cycles events is adapted to a seasonal environment of abiotic and biotic environmental factors. Climate change is likely to alter abiotic and also indirectly biotic environmental parameters and hence may influence its match/mismatch will copepod life cycle decisions. We propose to analyse a long-term time series of copepod abundances in Lake Constance of four copepod species with a high temporal and ontogenetic resolution in respect to the influence of climate variability on copepod population dynamics, demography, and the match/mismatch of copepod life history decisions with their environment. The four copepod species differ in important aspects of ther life history, i.e. occurrence and timing of diapause, and hence are ideally suited for such a comparative analysis. We will use matrix population models and relates methods to infer vital rates (mortality rates) from stage-structured data. Subsequently, mortality rates, abundance data, as well as data on the timing of life cycle events will be analysed by different time series analysis methods, e.g., by using time series decomposition techniques, transfer functions and dynamic linear models. This will allow us to investigate the direct and indirect effects of climate variability on the population dynamics of copepods in Lake Constance. Due to the exceptional quality of the data set these investigations will give us insights into the regulation of copepod dynamics in general.
