An island biogeographical view of the successional pathway in wet dune slacks

Authors

  • Beatrijs Bossuyt,

    Corresponding author
    1. Laboratory for Forest, Nature and Landscape Research, University of Leuven, Vital Decosterstraat 102, B-3000 Leuven, Belgium
      Corresponding author; Fax +3216329760; E-mail beatrijs.bossuyt@agr.kuleuven.ac.be
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  • Olivier Honnay,

    1. Laboratory for Forest, Nature and Landscape Research, University of Leuven, Vital Decosterstraat 102, B-3000 Leuven, Belgium
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  • Martin Hermy

    1. Laboratory for Forest, Nature and Landscape Research, University of Leuven, Vital Decosterstraat 102, B-3000 Leuven, Belgium
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Corresponding author; Fax +3216329760; E-mail beatrijs.bossuyt@agr.kuleuven.ac.be

Abstract

Abstract. Wet dune slacks occur as small, naturally fragmented systems in the dune landscape, isolated from other slacks. We studied the effects of slack isolation and area on the rate and direction of primary succession in a chronosequence of dune slacks. The results indicate that important changes occur in community characteristics over a period of 50 yr. Total cover and number of species increase as a result of the endogenous succession process, during which organic matter and nutrients accumulate. Consequently, competitive interactions shift from competition for nutrients to competition for light. Local factors thus determine, at least partially, the community composition in the slack. However, differences in community composition with increasing age are smaller when the slack is more isolated or smaller, suggesting a slower succession rate and biomass accumulation. Together with a lower contribution of slow dispersing species in more isolated slacks, this indicates that species accumulation is dispersal limited and thus influenced by regional factors. The stochastic variation resulting from this dispersal limited species accumulation causes a divergent successional pathway.

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