A common dilemma in ecosystem modeling is the complexity of biological systems and the lack of sufficient data. Traditional modeling approaches require quantitative data and detailed knowledge of the ecological system. Although such data may be available for small controlled systems such as the laboratory microcosm, in most cases sufficient information is not available for large natural systems. Qualitative modeling is a recent modeling approach developed to alleviate this problems. Qualitative models encapsulate more complex submodels by replacing continuous quantitative variables with descriptive state variables and equations with "if...then" transition rules. This approach follows the recent development in hierarchical ecosystems theory and provides a compromise position between complex models and insufficient data. The use of qualitative models in ecology has been limited up to now and the software tools for the researcher has been constrained to programs implemented for specific case studies. In this study the investigators propose to develop a general qualitative modeling program applicable to wide range of ecological problems. The program will be based on an intuitive graphical interface conferring the benefits of easy access for users without specialized programming knowledge.
