The formation of species pools: historical habitat abundance affects current local diversity

Authors

  • Martin Zobel,

    Corresponding author
    1. Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu 51005, Estonia
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  • Rüdiger Otto,

    1. Island Ecology and Biogeography Research Group, Department of Ecology, University La Laguna, La Laguna 38207, Canary Islands, Spain
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  • Lauri Laanisto,

    1. Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu 51005, Estonia
    2. Department of Biodiversity and Evolutionary Biology, National Museum of Natural Science, CSIC, C/Gutierrez Abascal, 2, ES–28006, Madrid, Spain
    3. Laboratorio Internacional en Cambio Global, UC-CSIC, Departamento de Ecología, Facultad de Ciencias Biológicas, PUC, Alameda 340, PC 6513677, Santiago de Chile, Chile
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  • Agustín Naranjo-Cigala,

    1. Department of Geography, University of Las Palmas de Gran Canaria, C/Pérez del Toro 1, CP: 35003, Las Palmas de Gran Canaria, Spain
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  • Meelis Pärtel,

    1. Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu 51005, Estonia
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  • José María Fernández-Palacios

    1. Island Ecology and Biogeography Research Group, Department of Ecology, University La Laguna, La Laguna 38207, Canary Islands, Spain
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Martin Zobel, Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu 51005, Estonia. E-mail: martin.zobel@ut.ee

ABSTRACT

Aim  Explanations of biogeographic diversity patterns have emphasized the role of large-scale processes that determine species pools, whereas explanations of local patterns have not. We address the hypothesis that local diversity patterns are also primarily dependent on the size of the available species pools, which are expected to be large when the particular habitat type has been evolutionary more abundant, or in unproductive habitats due to shorter generation time and hence higher diversification rates.

Location  The Canary Islands.

Methods  We determined the geographic distribution and habitat requirements of all native vascular plant species in the Canary Islands. Species pools for each habitat type on particular islands were further split into two categories according to origin: either originating due to local diversification or due to natural immigration. The dependence of historical diversification and diversification rate on habitat type, area, age, altitude and distance to the mainland was tested with general linear mixed models weighed according to the Akaike information criterion.

Results  The largest portion of the local variation in plant species diversity was attributed to the historic (pre-human) habitat area, although island age was also important. The diversification rate was higher in unproductive habitats of coastal scrub and summit vegetation.

Main conclusion  Our study supports the species pool hypothesis, demonstrating that natural local patterns of species diversity in different habitats mirror the abundance of those particular habitats in evolutionary history. It also supports the community-level birth rate hypothesis, claiming that stressful conditions result in higher diversification rates. We conclude that much of the observed local variation in plant diversity can be attributed to the differing sizes of species pools evolved under particular habitat conditions, and that historic parameters are far more important determinants of local diversity than suggested by ecological theory.

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