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

Multiple modelling paradigms are necessary to formulate crucial modelling p roblems in modern environmental science. Modelling paradigms help researche rs to conceive, formulate and solve problems by providing semantic structur es to organise their view of a system or process. An unusually large array of different paradigms is used in Ecology, reflecting the complexity and va riety of the natural world. As a result of this, multi-disciplinary problem s in particular suffer of representational difficulties that prevent them t o be approached efficiently with available software toolkits. In this paper I outline the theoretical aspects of model compatibility in the operationa l aspects of representation, scale and domain, and I describe the Integrati ng Modelling Architecture (IMA), a declarative framework and an open-source software toolkit to allow integrated meta-modelling. The IMA allows to spe cify generic model components using a common markup language, and loads par adigm-specific grammars that can be extended to support multiple paradigms. Among the project's goals are: (1) allow web-based integration of models a nd state-of-the-art resources distributed across a wide area network; (2) i ntegrate and reuse existing simulation programs and toolkits; (3) allow int egration between independently developed models adopting different modellin g paradigms, scales, and domains; and (4) provide extendible, efficient and clear abstractions to conceptualise and solve complex, multiple-paradigm m odelling problems in environmental science. At the end of the paper I argue that an integrative meta-modelling paradigm allows us to formulate and sol ve new important problems, and illustrate some of the new modelling scenari os enabled by the availability of these new concepts and tools. (C) 2001 El sevier Science B.V. All rights reserved.