The structural and functional connectivity of the grassland plant Lychnis
flos-cuculi |
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Authors: | T Aavik R Holderegger J Bolliger |
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Institution: | 1.Institute of Ecology and Earth Sciences,
University of Tartu, Tartu, Estonia;2.Institute of Integrative Biology, ETH
Zürich, Zürich, Switzerland;3.WSL Swiss Federal Research Institute, Birmensdorf, Switzerland |
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Abstract: | Understanding the relationship between structural and functional connectivity is
essential for successful restoration and conservation management, particularly in
intensely managed agricultural landscapes. We evaluated the relationship between
structural and functional connectivity of the wetland plant Lychnis flos-cuculi
in a fragmented agricultural landscape using landscape genetic and network approaches.
First, we studied the effect of structural connectivity, such as geographic distance and
various landscape elements (forest, agricultural land, settlements and ditch verges), on
gene flow among populations as a measurement of functional connectivity. Second, we
examined the effect of structural graph-theoretic connectivity measures on gene flow among
populations and on genetic diversity within populations of L. flos-cuculi. Among
landscape elements, forests hindered gene flow in L. flos-cuculi, whereas gene
flow was independent of geographic distance. Among the structural graph-theoretic
connectivity variables, only intrapopulation connectivity, which was based on population
size, had a significant positive effect on gene flow, that is, more gene flow took place
among larger populations. Unexpectedly, interpopulation connectivity of populations, which
takes into account the spatial location and distance among populations, did not influence
gene flow in L. flos-cuculi. However, higher observed heterozygosity and lower
inbreeding was observed in populations characterised by higher structural interpopulation
connectivity. This finding shows that a spatially coherent network of populations is
significant for maintaining the genetic diversity of populations. Nevertheless, lack of
significant relationships between gene flow and most of the structural connectivity
measures suggests that structural connectivity does not necessarily correspond to
functional connectivity. |
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Keywords: | gene flow genetic diversity graph theory inbreeding landscape genetics |
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