Costs of persistence and the spread of competing seeders and sprouters

Authors

  • Steven I. Higgins,

    Corresponding author
    1. Institut für Physische Geographie, Johann Wolfgang Goethe-Universität Frankfurt am Main, Altenhoeferallee 1, 60438 Frankfurt a.m., Germany;
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  • Olivier Flores,

    1. CNRS, Centre d’Ecologie Fonctionnelle et Evolutive UMR 5175, 1919, route de Mende, 34293 Montpellier, Cedex 5, France; and
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  • Frank M. Schurr

    1. Plant Ecology and Nature Conservation, Institute of Biochemistry and Biology, University of Potsdam, Maulbeerallee 2, 14469 Potsdam, Germany
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*Correspondence author. E-mail: higgins@em.uni-frankfurt.de

Summary

  • 1Trade-offs between reproduction and persistence are thought to regulate life-history evolution and competitive interactions between plants. We examined how seeder (non-persistent semelparous) and sprouter (persistent iteroparous) life-history strategies compete in fire prone shrublands.
  • 2Our hypothesis was that a trade-off between persistence and colonization ability implies that seeders would be better colonizers than sprouters and would therefore stand to benefit from periods of rapid climate change, whereas sprouters are candidates for extinction in periods of shifting climates because of their relatively poor ability to colonize.
  • 3We developed an individual based simulation model that simulates lottery plant competition in a homogeneous spatial arena. We used an indirect method to estimate the fecundity and dispersal parameters needed by the model. Dispersal was described by a lognormal dispersal kernel.
  • 4We found that coexistence was possible in the system only for a restricted range of conditions. Moreover, the model when parameterized using our empirical estimates of demographic and dispersal rates, suggested that the sprouting strategies have a competitive advantage in the system we studied.
  • 5The migration capacities of the sprouter species were substantially lower than those of the seeder species. Our simulations suggested that, even though sprouters had a competitive advantage over seeders, interspecific competitive interactions did not slow the spread of seeder species, but did substantially hamper the spread of the slower spreading sprouter species.
  • 6Synthesis. We conclude that, in fire driven systems characterized by lottery recruitment, existing theories of colonization – persistence trade-offs do not completely describe interactions between persistent and non-persistent strategies. Moreover, our investigation of seeder – sprouter interactions suggests that sprouters, even though they might be competitively superior, will be more threatened by periods of rapid climate change because of their limited colonization ability.

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