Planktonic interactions: developments and perspectives

摘要

In the 17th century Van Leeuwenhoek discovered the microscope and was the first to use it to observe plankton in water. He was amazed by the staggering diversity of these microscopic organisms. Many years of descriptive studies followed, and only in the middle of the 20th century did Naumann (1932) start to quantify phytoplankton biomass. He introduced the terms eutrophic and oligotrophic for lakes. Other pioneers in limnology and planktonic research were Hutchinson (1967) and his associate Lindeman (1942). They aimed to both describe and quantify food web interactions between aquatic organisms forming a basis for the idea that phytoplankton was not only controlled by nutrients (i.e. by bottom-up control), but also by their predators (i.e. by top-down control, Fig. 1). HrbAcek. (1962) was one of the first to demonstrate top-down control in ponds. Interactions such as predation, grazing and resource competition, together with abiotic features, explain the variations in abundance, biomass, and succession of planktonic organisms within an ecosystem. These processes and models, such as the PEG-model of seasonal succession of freshwater plankton (Sommer et al. 1986), have long been the focus of plankton research.