DOI: 10.5061/dryad.n02v6wx1j
title: Data from: Does the reduction of seed dormancy during ex situ cultivation affect the germination and establishment of plants reintroduced into the wild?

description: 1. Plants or seeds produced in botanic gardens or nurseries have become an
 important source of plant material for reintroductions or population
 reinforcements. However, recent research has shown that these living
 collections bear the risk of being genetically impoverished and adapted to
 the artificial habitat. In particular, many studies have reported a
 decline of seed dormancy during ex situ cultivation, which may compromise
 their suitability for reintroduction programs. However, the impact of
 those ex situ-derived changes on the germination and establishment of
 reintroduced plant populations is still unclear. 2. We studied the
 germination behaviour, population establishment and plant fitness over
 three years of reintroduced plants of the short-lived perennial Digitalis
 lutea, comparing plants grown from (1) a 30-year botanic garden
 population, (2) seeds from a seed bank representing the initial starting
 point of the botanic garden culture, and (3) a re-sampled corresponding
 wild population. 3. Under laboratory conditions, wild-collected seeds
 required cold stratification to germinate, whereas seeds from the garden
 population germinated without stratification. This pattern was strongly
 reduced in an outdoor pot experiment, where only a few garden seeds
 germinated before winter, and all seeds remained dormant when seeded in
 the natural area of origin. In a transplant experiment, reintroduced
 plants from the wild population outperformed both, the garden and the seed
 bank plants, in their fitness in the first 3 years after reintroduction
 suggesting adaptation to current climatic conditions. 4. Synthesis and
 Applications: Our study demonstrates that trait changes that occurred
 during ex situ cultivation can negatively impact the establishment of
 reintroduced plants. We conclude that wild plant material collected from
 contemporary populations is best suited for reintroduction and should be
 preferred over ex situ-cultivated and seed bank stored material,
 especially when the cultivation spanned multiple generations. However, our
 study also shows that germination requirements change in complex ways, and
 the loss of dormancy observed under laboratory conditions may not always
 be directly transferable to natural conditions. When established standards
 are respected, ex situ propagated material may thus still be a valuable
 resource, especially when wild material is not available in sufficient
 quantities.
description: The data is divided into 5 datasets: 1:
 germination_lab: is the germination rates of seeds of
 <em>Digitalis</em> <em>lutea</em> germinated in
 Petri dishes. Germination is calculated per Petri dish in
 percentage 2: germination_outdoor: is the germination
 of seeds of <em>Digitalis</em> <em>lutea</em> in
 outdoor pots after outdoor overwintering of the seeds in pots. Germination
 is a ratio (from 0 to 1). 3: germination_field: is the
 germination of seeds of <em>Digitalis</em>
 <em>lutea</em> in the field in iron rings pushed into the
 ground. Germination is a ratio (from 0 to 1).  4:
 performance_transplantation: is the performance of
 <em>Digitalis</em> <em>lutea</em> plants
 transplanted into three different sites and survival and performance (and
 flowering) measured over three consecutive years (2017-2019).
 5: total_fitness_aggregated: is the TotalFit is the cummulative
 flower number as calculated by Leverich & Levin 1979 and as called
 total fitness in these analyses. TotalFit has been calculated from the
 performance_transplantation file and is aggregated on the seed family
 level.