Abstract
We address the question how global change will affect the biodiversity of aquatic ecosystems using three influential theories as guidance: - The intermediate-disturbance hypothesis - The chaos & biodiversity hypothesis - The alternative-stable-state hypothesis Interestingly, these three theories seem to predict different relations between global warming and biodiversity. This is a first indication that relations between global change and aquatic biodiversity are not necessarily simple. To explore the potentially complex relation between global change and aquatic biodiversity in more detail, we propose to use time series analysis and model analysis. The time series analysis will focus on time series of lakes in Northwestern Europe, with the following aims: (i) a characterization of the existing patterns in relevant climatic variables (temperature, hours of sunshine, ice cover) in these lakes, and (ii) detection of anomalies in these climatic variables, (iii) detection of relations between plankton variability and the variability of these climatic variables. The model analyses will be based on simple multispecies versions of (i) competition models, (ii) predator-prey models, and (iii) foodweb models. These analyses will focus on the question how enhanced growth rates (owing to elevated temperatures), physiological and genetic adaptation, and changes in disturbance regimes will affect biodiversity in these three types of models. We will use abstract model formulations to obtain a better qualitative understanding, and we will use the climatic variability observed in the time series analysis as input for the models to obtain a better quantitative understanding. The findings from the model analysis and time series analysis will be compared with experimental results obtained in the companion project of this research program. The anticipated results of this research programme will provide the first essential tools to assess the potential impact of climate change on aquatic biodiversity.
Netherlands