20 DLES: A Component-Based Framework for Ecological Modeling Maria Bezrukova*, Vladimir Shanin*, Alexey Mikhailov*, Natalia Mikhailova y , Yulia Khoraskina*, Pavel Grabarnik*, Alexander Komarov* * INSTITUTE OF PHYSICO-CHEMICAL AND BIOLOGICAL PROBLEMS IN SOIL SCIENCE OF THE RUSSIAN ACADEMY OF SCIENCES, 142290 INSTITUTSKAYA UL., 2, PUSHCHINO, MOSCOW REGION, RUSSIA, y INSTITUTE OF MATHEMATICAL PROBLEMS OF BIOLOGY OF THE RUSSIAN ACADEMY OF SCIENCES, 142290 INSTITUTSKAYA UL., 4, PUSHCHINO, MOSCOW REGION, RUSSIA 20.1 Introduction Evolution of knowledge about the structure and driving forces of ecosystem change has led to great advances in ecological modeling. Progress in computing techniques, software engineering, and mathematical tools has simplified the development of methods of investigation of its specific problems. In the past, models were usually created by small research groups or even individual researchers in an ad hoc manner (Wilson, 2006). In contrast, models are now being developed by large groups from different institutions. These models are based on state-of-the-art findings and data from ecology, plant phys- iology, pedology, earth sciences, climatology, and so on. Moreover, a holistic approach to ecological modeling is necessary, i.e., the researcher should consider the ecological system as a whole instead of simulating its individual parts. The traditional approach to software development assumes that there is a finite set of requirements for a software solution, which can change only insignificantly, in contrast to exploratory scientific programming which can be characterized by a high degree of variability in its requirements. Another distinction is that commercial software has a well- defined life cycle with periodical release of new versions. In contrast, the process of scientific software development is continuous, often with several working solutions or even rollbacks to previous versions. To avoid duplicating work and “reinventing the wheel,” it is necessary to take advantage of code reuse. Code reuse, i.e. including earlier- created components in the system, is one of the basic techniques to reduce labor contribution while developing software (Wenderholm, 2005). As ecosystem processes have a very wide range of spatial and temporal scales, it is possible to develop a large number of models to simulate these processes. The Models of the Ecological Hierarchy. DOI: http://dx.doi.org/10.1016/B978-0-444-59396-2.00020-1 331 ISSN 0167-8892, Copyright Ó 2012 Elsevier B.V. All rights reserved