Species coexistence by permanent spatial heterogeneity in a lottery model.

We studied the effect of permanent spatial heterogeneity in promoting species coexistence in a lottery model. The system consisted of multiple habitats, each composed of a number of sites occupied by adults of two species. Larvae produced from different habitats were mixed in a common pool. When an adult died, the vacant site became occupied by an individual randomly chosen from the larval pool. If there were n habitats, there could be up to n-1 internal equilibria with both species in addition to two single-species equilibria. These equilibria and their local stability can be calculated from a single function, indicating the difference among species in their average lifetime reproductive success. Our main result is that between-habitat variation in the ratio of mortalities of two species promotes coexistence, while that of reproductive rates does not. This conclusion is the opposite of the role of temporal variation in the standard lottery model, in which between-year variation in the reproductive rate, but not that in the mortalities, promotes coexistence.

[1]  C. Strobeck,et al.  Necessary and Sufficient Conditions for Multiple-Niche Polymorphism in Haploids , 1975, The American Naturalist.

[2]  F. B. Christiansen.  Hard and Soft Selection in a Subdivided Population , 1975, The American Naturalist.

[3]  Yoh Iwasa,et al.  Dynamics of a metapopulation with space-limited subpopulations , 1986 .

[4]  D. S. Stoner.  Vertical Distribution of a Colonial Ascidian on a Coral Reef: The Roles of Larval Dispersal and Life-History Variation , 1992, The American Naturalist.

[5]  P. Chesson,et al.  The Roles of Harsh and Fluctuating Conditions in the Dynamics of Ecological Communities , 1997, The American Naturalist.

[6]  P. Chesson,et al.  Environmental Variability Promotes Coexistence in Lottery Competitive Systems , 1981, The American Naturalist.

[7]  A. Hastings.  Disturbance, coexistence, history, and competition for space , 1980 .

[8]  Yoh Iwasa,et al.  Interspecific competition among metapopulations with space-limited subpopulations , 1986 .

[9]  Yoh Iwasa,et al.  Phenological Pattern of Tree Regeneration in a Model for Forest Species Diversity , 1996 .

[10]  S. Levin.  Population Dynamic Models in Heterogeneous Environments , 1976 .

[11]  P. Chambers,et al.  Habitat partitioning in riverine macrophyte communities , 1996 .

[12]  J. Roughgarden,et al.  Larval settlement rate: A leading determinant of structure in an ecological community of the marine intertidal zone. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[13]  I. Noble,et al.  Dispersal, Variability, and Transient Niches: Species Coexistence in a Uniformly Variable Environment , 1985, The American Naturalist.

[14]  E. Dempster.  Maintenance of genetic heterogeneity. , 1955, Cold Spring Harbor symposia on quantitative biology.

[15]  P. Yodzis,et al.  Competition for Space and the Structure of Ecological Communities , 1978 .

[16]  R. Scheibling,et al.  Effects of whelk (Nucella lapillus (L.)) predation on mussel (Mytilus trossulus (Gould), M. edulis (L.)) assemblages in tidepools and on emergent rock on a wave-exposed rocky shore in Nova Scotia, Canada , 1998 .

[17]  Peter Chesson,et al.  Coexistence of Competitors in Spatially and Temporally Varying Environments: A Look at the Combined Effects of Different Sorts of Variability , 1985 .

[18]  Stephen P. Ellner,et al.  Coexistence of plant species with similar niches , 1984, Vegetatio.

[19]  H. Levene,et al.  Genetic Equilibrium When More Than One Ecological Niche is Available , 1953, The American Naturalist.

[20]  R. Cowling,et al.  A shared niche ? The case of the species pair Protea obtusifolia-Leucadendron meridianum , 1997 .

[21]  P. Sale.  Maintenance of High Diversity in Coral Reef Fish Communities , 1977, The American Naturalist.

[22]  David Tilman,et al.  Limiting Similarity in Mechanistic and Spatial Models of Plant Competition in Heterogeneous Environments , 1994, The American Naturalist.

[23]  Peter Chesson,et al.  The Storage Effect in Stochastic Population Models , 1984 .

[24]  Simon A. Levin,et al.  A Spatial Patch Dynamic Modeling Approach to Pattern and Process in an Annual Grassland , 1994 .

[25]  F. Chapin,et al.  SOIL HETEROGENEITY AND PLANT COMPETITION IN ANANNUAL GRASSLAND , 1997 .

[26]  Jonathan Roughgarden,et al.  THEORY OF MARINE COMMUNITIES: THE INTERMEDIATE DISTURBANCE HYPOTHESIS , 1998 .

[27]  S. Levin.  Lectu re Notes in Biomathematics , 1983 .

[28]  C. Strobeck.  Haploid Selection with n Alleles in m Niches , 1979, American Naturalist.

[29]  P. Chesson,et al.  Diffusion analysis and stationary distribution of the two-species lottery competition model , 1989 .