Abstract
How will global change affect the biodiversity of aquatic ecosystems? To tackle this question, we base our work on three influential theories: - 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. To explore the potentially complex relation between global change and aquatic biodiversity in more detail, we propose to test specific hypothesis generated from these theories experimentally in microcosms and do additional analysis using 'electronic cosms'. The microcosm experiments will consist of a bitrophic system, phytoplankton and zooplankton, under controlled nutrient, light and temperature conditions. In different experiments we will manipulate the composition of the phytoplankton or the zooplankton community and additionally impose different temperature and light regimes to study climatic effects on biotic interactions and biodiversity in this planktonic system. The initial conditions and the "climatic regimes" during the experiments will be tuned to the results of the time series analysis and the model analysis obtained in the companion project. Since climatic effects on more complex food webs and on organisms with long generation times cannot be studied experimentally, we will make use of an existing general lake model. We will use this full-scale ecosystem model as an 'electronic cosm', focusing on the same questions as we do in the experimental microcosms. The findings from the microcosm experiments and the additional analysis with the 'electronic cosms' will be compared with the results obtained by time series and model analysis 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