Das Projekt "Die Rolle von Simulationsmodellen bei der integrierten Auswertung" wird vom Umweltbundesamt gefördert und von Eidgenössische Anstalt für Wasserversorgung, Abwasserreinigung und Gewässerschutz, Abteilung für Umweltphysik durchgeführt. Uncertainties in scientific knowledge are often identified with ignorance. In complex systems, however, irreducible uncertainties are essential elements of system dynamics. The project aims at developing modeling tools that express essential elements of the dynamics of climate and ecosystems leaading to uncertainties. Such modelling tools are required to convey the importance and meaning of irreducible uncertainties. Model versions tuned to the specific requirements of an interactive use by laypersons will be developed. Such models will be simple in structure and comprise only the essential elements that are required to reproduce certain dynamic phenomena. Correspondingly, thes models will contrast with the rather elaborate models that are developed within the various projects of CLEAR. The model construction will proceed from the identification of keq phenomena in close collaboration with other projects, via the development of appropriate mathematical models that give a qualitative aggreement with the more sophisticated models and emirical data, to the establishment of appropriate user interfaces. Special emphasis will be put on the transparent representation of uncertainties inherent in the modelling process thus allowing an informed judgement by the user. The experience gained will lead to an improved understanding for irreducible uncertainties inherent in the behaviour of complex dynamic systems. This is an essential requirement for an appropriate integration and valuation of scientific knowledge in a process of integrated assessment in the field of climate change in particular and in the field of environmental research in general. Due to its being located at the interface between natural and social sciences the project will make an important contribution to improve the collaboration across disciplinary boundaries. Leading Questions: What are important sources of uncertainty in assessing impacts of regional climate change? Can simulation models serve as communication tools as the interface between science and society to convey implications of complexity?
Das Projekt "Modellierung von Oekosystemen" wird vom Umweltbundesamt gefördert und von Eidgenössische Anstalt für Wasserversorgung, Abwasserreinigung und Gewässerschutz, Abteilung für Umweltphysik durchgeführt. An ecosystem's stability has far too often been associated with the idea of a static equilibrium point generated by a rigid control. However, it is the trade-off between global and local variability arising from the interplay between the levels of the components and the system as a whole that results in functional integrity combined with a high potential for change. In the current project an approach is developed which takes into account different levels of organization. It is based on a general ecosystem framework depicting the structure of ecological networks along the dimensions of time, space and function. Model simulations are used to investigate the importance of spatio-temporal and functional diversity for an ecosystem's dynamics and organization and to seek for regularities in the relationship between ecosystem structure and function. A major result of the research will be descriptors which allow to assess an 'ecosystem's state of health'. A perspective of ecosystems as self-organizing systems operating far from their equilibrium state has major implications for research and management in general and for the role of mathematical models in particular. Models of complex systems may serve as tools to increase and communicate our understanding about the dynamic nature of complex systems and the necessity to admit a pluralism of complementary perspectives. They can highlight a kind of macroscopic uncertainty principle which enables and constrains researchers of complex systems to practice new forms of valuing and disseminating scientific knowledge. Leading Questions: How can we characterize the spatio-temporal organization of the energy and matter network of an ecosystem? What are the characteristics of pelagic systems? How is the organization of a system related to its physical environment - comparison between aquatic and terrestrial systems? What are characteristics of complex ecological (economic) networks? Can we derive quantitative descriptors for ecosystem health?