ECOWIN — an object-oriented ecological model for aquatic ecosystems

This paper presents an object-oriented approach to ecological modelling, and develops the underlying concepts into a structure which relates a set of “ecological” objects by means of a server, or shell, which effectively allows these to interact with each other, and displays the results of their interaction. An ecological model, ECOWIN, has been developed using this methodology, and this work examines the framework of the model, and describes its general layout. The basic structure of each object consists of a public section, which interacts with other objects and with the shell, and a private section, which carries out the activities which are characteristic of the object. The forms in which objects interact, and some of the advantages and difficulties of those interactions are discussed. Some “typical” objects are characterised, with the focus on the possibilities of adaptation and extensibility, using for instance, the concepts of inheritance and polymorphism. Some results obtained during the development and testing of the model in two different estuarine ecosystems are also shown, providing a practical application of the concepts and methodologies discussed herein. The virtues of using an object-oriented approach to ecological modeling appear to be, on the one hand, the ease of development and flexibility associated with the modularity and inheritance properties of the objects themselves, and on the other, the much greater conceptual approximation between natural ecosystems and interacting objects, relative to conventional structured programming methods.