DOI: 10.5061/dryad.2280gb5pd
title: Data from: Hurricanes overcome migration lag and shape intraspecific genetic variation beyond a poleward mangrove range limit

description: Expansion of many tree species lags behind climate-change projections.
 Extreme storms can rapidly overcome this lag, especially for coastal
 species, but how will storm-driven expansion shape intraspecific genetic
 variation? Do storms provide recruits only from the nearest sources, or
 from more distant sources? Answers to these questions have ecological and
 evolutionary implications, but empirical evidence is absent from the
 literature. Hurricane Irma provided an opportunity to address this
 knowledge gap at the northern range limit of the neotropical black
 mangrove (Avicennia germinans) on the Atlantic coast of Florida, USA. We
 observed massive post-hurricane increases in beach-stranded A. germinans
 propagules at, and past, this species’ present-day range margin when
 compared to a previously-surveyed, non-hurricane year. Yet, propagule
 dispersal does not guarantee subsequent establishment and reproductive
 success (i.e., effective dispersal). We also evaluated prior effective
 dispersal along this coastline with isolated A. germinans trees identified
 beyond the most northern established population. We used 12 nuclear
 microsatellite loci to genotype hurricane-driven drift propagules from
 nine sites (n = 896 propagules) and isolated trees from four sites (n = 10
 trees), determined their sources of origin, and estimated dispersal
 distances. Almost all drift propagules and all isolated trees came from
 the nearest sources. This research suggests that hurricanes are a
 prerequisite for poleward range expansion of a coastal tree species and
 that storms can shape the expanding gene pool by providing almost
 exclusively range-margin genotypes. These insights and empirical estimates
 of hurricane-driven dispersal distances should improve our ability to
 forecast distributional shifts of coastal species.
description: Genotype data (drift propagules) – 896 <em>Avicennia
 germinans</em> (black mangrove) drift propagules collected at nine
 beach survey sites along the Atlantic coast of Florida, USA on 14-16
 October, 2017 (five weeks after Hurricane Irma made landfall in
 Florida). Genotype data (vagrant trees) - 10 isolated
 <em>A. germinans</em> trees from four locations beyond the
 most northern established population of this species along the Atlantic
 coast of Florida. Samples were collected between July 2016 and June
 2017. Genotype data (reference source populations) -
 Reference data set of 12 <em>A. germinans</em> source
 populations that encompass the entire Florida distribution of this
 species. This data set used inter-population FST = 0.1 to reduce the 32
 Florida collection sites in the Kennedy et al (2020) data set:
 https://doi.org/10.5061/dryad.69p8cz8xh
description: Genotype data (drift propagules) – column 1: site (identification
 code for collection site); column 2: ID (identification code for sampled
 propagule); column 3: lat (latitude at central point for each survey
 site); column 4-27: multi-locus microsatellite genotype (12-loci). *NOTE:
 blank cells are missing data Genotype data (vagrant
 trees) – column 1: site (identification code for collection site); column
 2: ID (identification code for sampled tree); column 3: lat (latitude for
 sampled tree); column 4-27: multi-locus microsatellite genotype
 (12-loci) Genotype data (reference source populations)
 – column 1: site (identification code for collection site); column 2: ID
 (identification code for sampled tree); column 3-26: multi-locus
 microsatellite genotype (12-loci). *NOTE: blank cells are missing
 data