Evol Ecol Res 8: 629-642 (2006)     Full PDF if your library subscribes.

The role of rare species in the community stability of a model ecosystem

Jin Yoshimura,1,2,3* Kei-ichi Tainaka,1 Takanori Suzuki,1 Yukio Sakisaka,2 Nariyuki Nakagiri,1,4 Tatsuya Togashi2 and Tatsuo Miyazaki2

1Department of Systems Engineering, Faculty of Engineering, Shizuoka University, Hamamatsu 432-8561, Japan,  2Marine Biosystems Research Center, Chiba University, Uchiura, Kamogawa, Chiba 299-5502, Japan,  3Department of Environmental and Forest Biology, State University of New York, Syracuse, NY 13210, USA and  4School of Human Science and Environment, University of Hyogo, Himeji 670-0092, Japan

Author to whom all correspondence should be addressed.
e-mail: jin@sys.eng.shizuoka.ac.jp

ABSTRACT

Question: Is a rare or low-density species important for the balance of an ecosystem?

Features of the model: Perturbation experiments on a model lattice with two common species and one low-density species.

Key variables: The low-density species is preyed upon by one of the common species, but it eats the other common species. Meanwhile, the latter common species is eaten by the first common species. Thus the relationship between the three species is cyclic, corresponding to the ‘rock–paper–scissors’ game. Control experiments include only two common species. Perturbation is introduced by decreasing the rate of reproduction of one of the common species.

Simulation results: The outcome of perturbations depends strongly on both the low-density species and the perturbation strengths. The responses to perturbation are often paradoxical and different from those expected from the mean-field or global version of the lattice model.

Conclusions: The presence of a low-density species can alter the balance of an ecosystem. The conservation biology and management practice of natural ecosystems may be hindered if less common, unattractive species are ignored.

Keywords: community structure, lattice ecosystems, low-density species, perturbation.

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        © 2006 Jin Yoshimura. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

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