Coastal Systems Ecology and Modeling Program

An Introduction to Ecosystem Modeling

"A complex field such as oceanography tends to be subject to two opposite approaches. The first is the descriptive, in which several quantities are measured simultaneously and their interrelationships derived by some sort of statistical method. The other approach is the synthetic one, in which a few resonable although perhaps oversimplified asumptions are laid down, these serving as a basis for mathematical derivation of relationships."

- Gordon A. Riley (1946)

With these words, Gordon Riley began his revolutionary development of the first numerical, dynamic, mechanistic model of a marine ecosystem—in his case, the annual phytoplankton dynamics on Georges Bank. Since that time, the field of marine ecosystem modeling grew with a particular flowering during the 1970s with the development of systems ecology by HT Odum and colleagues, resulting in many still classic models designed to understand system structure and function.The field exploded in the mid-1990s with the development of powerful desktop computers and has come into its own as a widely used tool in both research and management of marine ecosystems.

ASFA plot

Source: Brush & Harris (2010) Ecol. Model. 221:965–968

Modeling is the process of building a mathematical abstraction of an actual system. The purpose in ecological modeling is often systems analysis, an approach that attempts to understand fundamental attributes of ecosystems with the goal of predicting behavior. Or a model can be purely descriptive, a way of discovering the mechanisms that explain the structure or behavior of an ecosystem.

Some advantages include:

Models provide a conceptual framework within which specific studies and experimental designs may be evaluated.
The process of modeling often identifies areas where information or data is inadequate or entirely lacking.
Simulation analysis can determine sensitive or controlling parameters that might otherwise be overlooked, thought unimportant, or completely ignored.
Models provide a tool to aid both current and future research by directing the effort to fill data gaps and providing better understanding of controlling parameters and interactions.
Modeling experiments (often referred to as model scenarios) allow "what-if" analyses of system behavior.
Models serve as an important hypothesis-generation tool.

Questions?

Contact Dr. Mark J. Brush
Coastal Systems Ecology and Modeling Program/ VIMS
PO Box 1346, Gloucester Point, VA 23062-1346, USA
Telephone: 804-684-7402; FAX: 804-684-7293