Copepods are among the most abundant multicellular organisms in the world. Despite their central role in all aquatic habitats ranging from the deep ocean to the glaciers, surprisingly little is known about their population dynamics under environmental changes. This thesis provides novel insights in the response of freshwater copepods to declining nutrient concentrations and climate variability with a primary focus on the role of seasonality, life cycle strategy, and stage-structured interactions. The first and second chapter analysed in detail the responses of two single copepod species with...