Petit Manan Lighthouse, off the Maine coast

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Computational Ecology

Modeling ecosystems. Ecosystems are extraordinarily complex assemblages of plants and animals interacting with each other, with the physical environment, and, increasingly, with humans. Ecology is the scientific field that seeks to understand ecosystems. Ecologists are turning to computer models to help them make their models of ecosystem processes concrete and to provide predictions about the future of the ecosystem. Computer models allow rapid testing of ecology ideas by simulation and provide the means to run "what-if" scenarios that would be difficult or impossible otherwise.

The Computer Science Department has ongoing computational ecology research in its MaineSAIL laboratory under the direction of Roy Turner. The work focuses on both small-scale interactions between ecosystem components as well as larger, ecosystem-wide simulation.

Predator-prey interactions. In marine ecosystems, surfaces that become cleared, for example by wave action or physical scraping, are colonized by organisms that interact and develop over time into so-called "fouling communities". Predicting where the succession of species will lead the community (e.g., mussel-dominated, barnacle-dominated, etc.) is difficult, as there are many factors affecting succession. Since ships' hulls, as well as new pilings and other underwater structures, fall into the category of cleared surfaces, studying these ecological systems is of more than academic interest.


Hydroid

Cordylophora lacustris, a hydroid.
(Photo courtesy David Belzard, UNH)

One potential determinant of the climax fouling community is predation of early settlers on other early settlers. In some estuarine communities, nudibranchs (sea slugs) prey on hydroids (colonial cnidarians similar to freshwater hydra). Hydroids, in turn, prey on other larvae settling on the substrate, but they prey on different kinds of larvae preferentially. Thus the degree of predation by nudibranchs on hydroids will likely affect the sucession of the system.

We have developed a predator-prey model for the nudibranch-hydroid system. By running simulations of the model under various conditions of assumed growth, etc., of the species, biologists can make predictions about the likely outcome of the predation events as well as the resulting impact on community succession.

Ecosystem-scale models. Work is currently ongoing to extend our computational ecology work to the level of an entire ecosystem. MEME (Maine ecosystem model of estuaries) of create a simplified model of community succession in an estuary.