Integrating modelling architecture: a declarative framework for multi-paradigm, multi-scale ecological modelling

Multiple modelling paradigms are necessary to formulate crucial modelling problems in modern environmental science. Modelling paradigms help researchers to conceive, formulate and solve problems by providing semantic structures to organise their view of a system or process. An unusually large array of different paradigms is used in Ecology, reflecting the complexity and variety of the natural world. As a result of this, multi-disciplinary problems in particular suffer of representational difficulties that prevent them to be approached efficiently with available software toolkits. In this paper I outline the theoretical aspects of model compatibility in the operational aspects of representation, scale and domain, and I describe the Integrating Modelling Architecture (IMA), a declarative framework and an open-source software toolkit to allow integrated meta-modelling. The IMA allows to specify generic model components using a common markup language, and loads paradigm-specific grammars that can be extended to support multiple paradigms. Among the project's goals are: (1) allow web-based integration of models and state-of-the-art resources distributed across a wide area network; (2) integrate and reuse existing simulation programs and toolkits; (3) allow integration between independently developed models adopting different modelling paradigms, scales, and domains; and (4) provide extendible, efficient and clear abstractions to conceptualise and solve complex, multiple-paradigm modelling problems in environmental science. At the end of the paper I argue that an integrative meta-modelling paradigm allows us to formulate and solve new important problems, and illustrate some of the new modelling scenarios enabled by the availability of these new concepts and tools. (C) 2001 Elsevier Science B.V. All rights reserved.