Abstract
We develop from basic principles a two-species differential equations model which exhibits mutualistic population interactions. The model is similar in spirit to a commonly cited model [Dean, A.M., Am. Nat. 121(3), 409–417 (1983)], but corrects problems due to singularities in that model. In addition, we investigate our model in more depth by varying the intrinsic growth rate for each of the species and analyzing the resulting bifurcations in system behavior. We are especially interested in transitions between facultative and obligate mutualism. The model reduces to the familiar Lotka–Volterra model locally, but is more realistic for large populations in the case where mutualist interaction is strong. In particular, our model supports population thresholds necessary for survival in certain cases, but does this without allowing unbounded population growth. Experimental implications are discussed for a lichen population.
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References
Ahmadjian, V., 1967. The Lichen Symbiosis. Blaisdell Publishing Co., Waltham, MA.
Büdel, B., 1992. Taxonomy of lichenized procaryotic blue-green algae. In: Reisser, W. (Ed.), Algae and Symbioses: Plants, Animals, Fungi, Viruses. Interactions Explored. Biopress Limited, Bristol, pp. 301–324.
Dean, A.M., 1983. A simple model of mutualism. Am. Nat. 121(3), 409–417.
Goh, B.S., 1979. Stability in models of mutualism. Am. Nat. 113(2), 261–275.
Graves, W.G. 2003. A comparison of some simple models of mutualism. Master's Project, University of Minnesota Duluth, available from the authors by request.
Graves, W.G., Peckham, B.B., Pastor, J., 2005. A 2D differential equations model for mutualism. Department of Mathematics and Statistics, University of Minnesota Duluth, Technical Report TR 2006-2.
Guckenheimer, J., Holmes, P., 1983. Nonlinear Oscillations, Dynamical Systems and Bifurcations Vector Fields. Springer, New York.
Hernandez, M.J., 1998. Dynamics of transitions between population interactions: A nonlinear interaction alpha-function defined. Pro. R. Soc. Lond. B 265(1404), 1433–1440.
Hirsch, M.W., Smale, S., Devaney, R.L., 2004. Differential Equations, Dynamical Systems and an Introduction to Chaos, 2nd edition. Elsevier/Academic Press, Amsterdam.
Kot, M., 2001. Elements of Mathematical Ecology. Cambridge University Press, Cambridge UK.
Miadlikowska, J., Lutzoni, F., 2004. Phylogenetic classification of peltigeralean fungi (Peltigerales, Ascomycota) based on ribosomal RNA small and large subunits. Am. J. Bot. 91(3), 449–464.
Miadlikowska, J., Lutzoni, F., Goward, T., Zoller, S., Posada, D., 2003. New approach to an old problem: Incorporating signal from gap-rich regions of ITS and rDNA large subunit into phylogenetic analyses to resolve the Peltigera canina species complex. Mycologia 95(6), 1181–1203.
Nutman, P.S. (Ed.), 1976. Symbiotic Nitrogen Fixation in Plants. Cambridge University Press, Cambridge, UK.
Pandey, K.D., Kashyap, A.K., Gupta, R.K., 2000. Nitrogen-fixation by non-heterocystous cyanobacteria in an Antarctic ecosystem. Isr. J. Plant Sci. 48(4), 267–270.
Peckham, B.B., 1986–2004. To Be Continued... (Continuation Software for Discrete Dynamical Systems), http://www.d.umn.edu/~bpeckham//tbc_home.html (continually under development).
Rai, A.N., 1988. Nitrogen metabolism. In: Galun, M. (Ed.), CRC Handbook of Lichenology, Vol. 1. CRC Press, Boca Raton, Florida. pp. 201–237.
Robinson, C., 2004. An Introduction to Dynamical Systems, Continuous and Discrete. Pearson/Prentice-Hall, Englewood Cliffs, NJ.
Sterner, R.W., Elser, J.J., 2002. Ecological Stoichiometry. Princeton University Press, Princeton, NJ.
Stewart, W.D.P., 1980. Some aspects of structure and function on N2-fixing cyanobacteria. Annu. Rev. Microbiol. 34, 497–536.
Strogatz, S.H., 1994. Nonlinear Dynamics and Chaos, Perseus Books, NY.
Vandermeer, J.H., Boucher, D.H., 1978. Varieties of mutualistic interaction in population models. J. Theor. Biol. 74, 549–558.
Wolin, C.L., 1985. The population dynamics of mutualistic systems. In: Boucher, D.H. (Ed.), The Biology of Mutualism. Oxford University Press, New York, pp. 248–269.
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Graves, W.G., Peckham, B. & Pastor, J. A Bifurcation Analysis of a Differential Equations Model for Mutualism. Bull. Math. Biol. 68, 1851–1872 (2006). https://doi.org/10.1007/s11538-006-9070-3
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DOI: https://doi.org/10.1007/s11538-006-9070-3