Data from: Estimating exotic gene flow into native pine stands: zygotic versus gametic components

Monitoring contemporary gene flow from widespread exotic plantations is
becoming an important problem in forest conservation genetics. In plants,
where both seed and pollen disperse, three components of exotic gene flow
with potentially unequal consequences should be, but have not been,
explicitly distinguished: zygotic, male gametic and female gametic.
Building on a previous model for estimating contemporary rates of zygotic
and male gametic gene flow among plant populations, we present here an
approach that additionally estimates the third (female gametic) gene flow
component, based on a combination of uni- and biparentally inherited
markers. Using this method and a combined set of chloroplast and nuclear
microsatellites, we estimate gene flow rates from exotic plantations into
two Iberian relict stands of maritime pine (Pinus pinaster) and Scots pine
(P. sylvestris). Results show neither zygotic nor female gametic gene flow
but moderate (6–8%) male gametic introgression for both species, implying
significant dispersal of pollen, but not of seeds, from exotic plantations
into native stands shortly after introduced trees reached reproductive
maturity. Numerical simulation results suggest that the model yields
reasonably accurate estimates for our empirical data sets, especially for
larger samples. We discuss conservation management implications of
observed levels of exposure to non-local genes, and identify research
needs to determine potentially associated hazards. Our approach should be
useful for plant ecologists and ecosystem managers interested in the
vectors of contemporary genetic connectivity among discrete plant
populations.