Species-specific effects of production practices on genetic diversity in plant reintroduction programs.

Plant production practices can influence the genetic diversity of cultivated plant materials and, ultimately, their potential to adapt to a reintroduction site. A common step in the plant production process is the application of seed pretreatment to alleviate physiological seed dormancy and successfully germinate seeds. In production settings, the seeds that germinate more rapidly may be favored in order to fill plant quotas.

Adaptation to pollination by fungus gnats underlies the evolution of pollination syndrome in the genus Euonymus.

Background And Aims: Dipteran insects are known pollinators of many angiosperms, but knowledge on how flies affect floral evolution is relatively scarce. Some plants pollinated by fungus gnats share a unique set of floral characters (dark red display, flat shape and short stamens), which differs from any known pollination syndromes. We tested whether this set of floral characters is a pollination syndrome associated with pollination by fungus gnats, using the genus Euonymus as a model.

Supporting long-term sustainability of ex situ collections using a pedigree-based population management approach.

Premise: Living collections maintained for generations are at risk of diversity loss, inbreeding, and adaptation to cultivation. To address these concerns, the zoo community uses pedigrees to track individuals and implement crosses that maximize founder contributions and minimize inbreeding. Using a pedigree management approach, we demonstrate how conducting strategic crosses can minimize genetic issues that have arisen under current practices.

Drivers of seedling establishment success in dryland restoration efforts.

Restoration of degraded drylands is urgently needed to mitigate climate change, reverse desertification and secure livelihoods for the two billion people who live in these areas. Bold global targets have been set for dryland restoration to restore millions of hectares of degraded land. These targets have been questioned as overly ambitious, but without a global evaluation of successes and failures it is impossible to gauge feasibility.

Taxonomic similarity does not predict necessary sample size for conservation: a comparison among five genera.

Effectively conserving biodiversity with limited resources requires scientifically informed and efficient strategies. Guidance is particularly needed on how many living plants are necessary to conserve a threshold level of genetic diversity in collections. We investigated this question for 11 taxa across five genera.

Applying the zoo model to conservation of threatened exceptional plant species.

Maintaining a living plant collection is the most common method of ex situ conservation for plant species that cannot be seed banked (i.e., exceptional species).

The right trait in the right place at the right time: Matching traits to environment improves restoration outcomes.

The challenges of restoration in dryland ecosystems are growing due to a rise in anthropogenic disturbance and increasing aridity. Plant functional traits are often used to predict plant performance and can offer a window into potential outcomes of restoration efforts across environmental gradients. We analyzed a database including 15 yr of seeding outcomes across 150 sites on the Colorado Plateau, a cold desert ecoregion in the western United States, and analyzed the independent and interactive effects of functional traits (seed mass, height, and specific leaf area) and local biologically relevant climate variables on seeding success.

Cracking the case: Seed traits and phylogeny predict time to germination in prairie restoration species.

Traits are important for understanding how plant communities assemble and function, providing a common currency for studying ecological processes across species, locations, and habitat types. However, the majority of studies relating species traits to community assembly rely upon vegetative traits of mature plants. Seed traits, which are understudied relative to whole-plant traits, are key to understanding assembly of plant communities.

Phylogeny and source climate impact seed dormancy and germination of restoration-relevant forb species.

For many species and seed sources used in restoration activities, specific seed germination requirements are often unknown. Because seed dormancy and germination traits can be constrained by phylogenetic history, related species are often assumed to have similar traits. However, significant variation in these traits is also present within species as a result of adaptation to local climatic conditions.

Keeping All the PIECES: Phylogenetically Informed Ex Situ Conservation of Endangered Species.

Ex situ conservation in germplasm and living collections is a major focus of global plant conservation strategies. Prioritizing species for ex situ collection is a necessary component of this effort for which sound strategies are needed. Phylogenetic considerations can play an important role in prioritization.

Influences of landscape and pollinators on population genetic structure: examples from three Penstemon (Plantaginaceae) species in the Great Basin.

Premise Of The Study: Despite rapid growth in the field of landscape genetics, our understanding of how landscape features interact with life history traits to influence population genetic structure in plant species remains limited. Here, we identify population genetic divergence in three species of Penstemon (Plantaginaceae) similarly distributed throughout the Great Basin region of the western United States but with different pollination syndromes (bee and hummingbird). The Great Basin's mountainous landscape provides an ideal setting to compare the interaction of landscape and dispersal ability in isolating populations of different species.

High variation in clonal vs. sexual reproduction in populations of the wild strawberry, Fragaria virginiana (Rosaceae).

Background And Aims: Many plants reproduce both clonally and sexually, and the balance between the two modes of reproduction will vary among populations. Clonal reproduction was characterized in three populations of the wild strawberry, Fragaria virginiana, to determine the extent that reproductive mode varied locally between sites. The study sites were fragmented woodlands in Cook County, Illinois, USA.

Plant conservation genetics in a changing world.

Plant conservation genetics provides tools to guide conservation and restoration efforts, measure and monitor success, and ultimately minimize extinction risk by conserving species as dynamic entities capable of evolving in the face of changing conditions. We consider the application of these tools to rare and common species alike, as ongoing threats that increasingly limit their resilience, evolutionary potential and survival. Whereas neutral marker studies have contributed much to conservation genetics, we argue for a renewed focus on quantitative genetic studies to determine how, or if, species will adapt to changing conditions.

The paradox of forest fragmentation genetics.

Theory predicts widespread loss of genetic diversity from drift and inbreeding in trees subjected to habitat fragmentation, yet empirical support of this theory is scarce. We argue that population genetics theory may be misapplied in light of ecological realities that, when recognized, require scrutiny of underlying evolutionary assumptions. One ecological reality is that fragment boundaries often do not represent boundaries for mating populations of trees that benefit from long-distance pollination, sometimes abetted by long-distance seed dispersal.