Abstract

Using ecosystems as examples, this chapter engages with the emergence of understanding life by producing and assembling modules of knowledge, and finally linking them to create a holistic picture of the entire system. Ecosystems as theoretical units of arbitrary size are understood to consist of abiotic and biotic components on the one hand and of the interactions of the components on the other. The latter is extraordinarily complex but generates functionality in the system as a basis of its properties and services. Functionality can be further partitioned into processes, such as flow of energy and matter, resulting from food chains or webs. Functional diversity is considered as a composite variable that includes all significant physiological information as processes and/or traits, weighted by their abundances in a community whose composition has been filtered by environmental conditions. Two types of ecological experiments can be used to unravel the significance of the interactions of species in a functional community: The analytical approach by intentional disturbance, i.e., a change of an external condition, or the synthetic approach by using artificial species compositions in an otherwise natural environment. Both approaches allow the characterization of functional modules in an ecosystem. Due to the complexity of even simple appearing modules like biomass production, models are required for a comprehensive insight. The more so linking modules to achieve a higher level of integration is unthinkable without comprehensive synthesis models. Examples are presented for each step in the emerging knowledge about, and understanding of ecosystems.