title: Dispersal responses override density effects on genetic diversity during post-disturbance succession.
abstract: Dispersal fundamentally influences spatial population dynamics but little is known about dispersal variation in landscapes where spatial heterogeneity is generated predominantly by disturbance and succession. We tested the hypothesis that habitat succession following fire inhibits dispersal, leading to declines over time in genetic diversity in the early successional gecko Nephrurus stellatus We combined a landscape genetics field study with a spatially explicit simulation experiment to determine whether successional patterns in genetic diversity were driven by habitat-mediated dispersal or demographic effects (declines in population density leading to genetic drift). Initial increases in genetic structure following fire were likely driven by direct mortality and rapid population expansion. Subsequent habitat succession increased resistance to gene flow and decreased dispersal and genetic diversity inN. stellatus Simulated changes in population density alone did not reproduce these results. Habitat-mediated reductions in dispersal, combined with changes in population density, were essential to drive the field-observed patterns. Our study provides a framework for combining demographic, movement and genetic data with simulations to discover the relative influence of demography and dispersal on patterns of landscape genetic structure. Our results suggest that succession can inhibit connectivity among individuals, opening new avenues for understanding how disturbance regimes influence spatial population dynamics.
authors.affiliation: Fenner School of Environment and Society, Australian National University, Fenner Building 141, Linnaeus Way, Canberra, Australian Capital Territory 2601, Australia annabel@smithecology.org.
authors.forename: Annabel L
authors.identifier: http://orcid.org/0000-0002-1201-8713
authors.initials: AL
authors.lastname: Smith
authors.affiliation: Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA.
authors.forename: Erin L
authors.initials: EL
authors.lastname: Landguth
authors.affiliation: School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Bull
authors.affiliation: Fenner School of Environment and Society, Australian National University, Fenner Building 141, Linnaeus Way, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Sam C
authors.initials: SC
authors.lastname: Banks
authors.affiliation: School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia Evolutionary Biology Unit, South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Gardner
authors.affiliation: Fenner School of Environment and Society, Australian National University, Fenner Building 141, Linnaeus Way, Canberra, Australian Capital Territory 2601, Australia School of Life and Environmental Sciences, Deakin University Geelong, 221 Burwood Highway, Burwood, Victoria 3125, Australia.
authors.forename: Don A
authors.initials: DA
authors.lastname: Driscoll
mesh_terms: D063147:Animal Distribution; D000818:Animals; D017753:Ecosystem; D005260:Female; D005390:Fires; D014644:Genetic Variation; D008116:Lizards / Q000235:genetics / Q000502:physiology*; D008297:Male; D008954:Models, Biological; D011157:Population Dynamics; D013021:South Australia
keywords: demographic population model; density dependence; fire; habitat fragmentation; landscape genetics; movement ecology