Submitted By: Klara Scharnagl
We are living in the Anthropocene. Every habitat on earth, no matter how remote, has been impacted by human activity. Human impacts include disturbance, development, or alteration of habitats; fluxes and deposition of nutrients and pollutants; overexploitation of resources; noise pollution; light pollution; introduction of invasive species; and climate change. Whether we are deep in the Amazon rainforest, high on the alpine tundra, or in the middle of an urban park, we must now consider our botanical research through the lens of the anthropocene.
To do so, we must become detectives, solving mysteries and looking for clues. What symbioses or species interactions once existed here that now no longer do? What community cohorts once existed that have now, in whole or in part, shifted? How large was this population in the past, and are its numbers dwindling? What is the resilience of each species to change? What are the direct and cascading effects of human impacts on the environment? How has the baseline shifted, and how will it continue to shift as the climate continues to change and the planet continues to warm?
To this colloquium we invite stories of plant and fungal responses to human impacts, including species adaptation and resilience to impact, and development of frameworks to assess shifting baselines. Any habitat type is welcome, but we are particularly excited to highlight any urban studies.
Submitted By: James Watkins
The field of neotropical pteridology has expanded significantly over the last two decades. Our knowledge of the systematic relationships of tropical taxa combined with an intentional focus on taxonomy, floristics, ecology, anatomy, and evolutionary development is developing new paradigms and ways of thinking about ferns. The intensification of pteridological research in the neotropics is not a random event: much of the interest has been driven by the mentoring efforts of Robbin Moran. Dr. Moran has been at the forefront of tropical fern education for over 30 years. He has taught several renditions of the Organization for Tropical Studies “Tropical Ferns and Lycophytes” course, and fern courses in Bolivia, Ecuador, and Venezuela. He has inspired decades of young investigators to consider ferns in their research and has collaborated directly with dozens of scientists from nearly every Latin American country on an incredible array of research topics. The goal of this symposium is to bring together a cohort of scientists to speak about their work on ferns and lycophytes across the neotropics with special emphasis on multidisciplinary topics that reflect the very spirit of Robbin Moran. The session will include speakers focusing on systematics, floristics, ecology, anatomy, and evolutionary development.
Submitted By: Scott Schuette
Although from different kingdoms, bryophytes and lichens share the coveted station of being among the oldest extant lineages of terrestrial organisms on the planet. These amazing denizens of our world evolved strategies of coping with, and sometimes thriving under the multitude of stressors from a plethora of habitats in this world. With but a few exceptions, bryophytes and lichens are mere components of larger plant communities and geological formations, depending on other plants for substrates and the associated microhabitats, yet provide a number of services within a larger matrix of ecosystems and biomes. The diversity of bryophytes and lichens that our planet offers has captured the attention of scientists and enthusiasts for centuries. Now in the 21<sup>st</sup> century we have the technology to detect taxonomic diversity at the genetic level even when morphological distinction is lacking. As a result, we are discovering new species of bryophytes and lichens further advancing our understanding of the biodiversity of these groups. However, this diversity is finite and under duress in a rapidly changing climate. The extreme changes to the climate will impact habitats and associated niches harboring bryophytes and lichens shifting conditions that may lead to species extinctions before we have the opportunity discover and/or work to protect them. This colloquium brings together early career scientists from different backgrounds and levels of education working to identify bryophyte and lichen diversity in our world, those exploring the roles of species in an ecosystem, and those working to conserve this biodiversity in our one and only world.
Submitted By: Jessie Pelosi
All plants undergo an alternation of generations between diploid sporophyte and haploid gametophyte life phases. The gametophyte life stage exhibits remarkable variation between different lineages of land plants, ranging from the dominant life stage in bryophytes to just a few cells in angiosperms. Changes to the gametophyte phase have likely influenced the evolution and differentiation of the major lineages of land plants, yet it is one of the most understudied aspects of plant biology. The gametophyte is perhaps best studied when both generations are free-living, a unique aspect to the pteridophytes (ferns and lycophytes). However, a comparative approach across clades is imperative to furthering our understanding of this enigmatic life phase. Across the plant tree of life, gametophytes occupy a range of growth habits (free-living vs. parasitic, subterranean vs. terrestrial, short vs. long-lived) and, contrary to traditional thought, can occupy physiological and ecological niche space larger than their respective sporophytes. Furthermore, the gametophyte is the site for sexual reproduction and is therefore a crucial aspect in coservation biology of plants. Although a handful of renowned botanists have been studying gametophytes for decades, many young scientists are starting to study the evolution, genomics, ecology, and conservation of this life stage. Despite a recent resurgence in the study of gametophyte biology, particularly amongst pteridologists, key questions in the field remain to be explored. In genomics/genetics: What genetic drivers separate the gametophyte and sporophyte phases? How does a single genome generate both gametophyte and sporophyte life stages? How does the genetic structure of gametophyte and sporophyte populations compare? In ecology and physiology: What are the relative stress responses of the gametophyte compared to the sporophyte? How does the niche of the gametophyte differ from that of the sporophyte? In systematics: What morphological characters aid in the identification and taxonomic treatment of gametophytes? Are gametophytic traits phylogenetically constrained and how do these traits impact the evolution of the organism? In conservation: What role does the gametophyte play in conserving genetic and species diversity? These and many more questions have yet to be investigated in this burgeoning field. This topic welcomes speakers who study diverse taxa across the entire phylogeny of land plants to explore questions in gametophyte biology.
Submitted By: Erika Hersch-Green
Angiosperms (flowering plants) show the widest variance in genome sizes (the total amount of DNA contained within a single somatic cell) amongst all eukaryote organisms, spanning more than a 2400-fold range. Several genome and chromosome processes such as polyploidization, transposon, retrotransposon and tandem repeat activity, streamlining, repair, and rearrangement processes have been proposed to contribute to the shrinking and/or expansion of plant genome size variation. While we know that polyploidy has a big impact on genome size variation within and among closely related species, recent evidence suggests that other processes (such as retrotransposon activity) might contribute more significantly to the genome size variation across the angiosperm phylogeny and amongst more distantly related lineages. Genome size might be an extremely important functional trait to consider when predicting the impacts that global changes (such as environmental alterations and/or invasive species introductions) could have on populations, communities, and ecosystems. For instance, both polyploidy and genome size variation (independently of polyploidy) have been shown to alter organismal cytological, chemical, morphological, and physiological traits and affect growth and fitness responses, competitive dynamics, preferences and tolerances, and species interactions – all of which can occur dependent upon environmental context. However, much of this research has been done on allopolyploids in which differences between cytotypes are confounded by hybridization and furthermore it is not known whether genome size variation from polyploidy versus other processes has similar or different effects on organismal traits and responses to global changes. This colloquium will examine how genome size variation independently of hybridization in plants and/or ferns influences organismal traits and/or ecological dynamics dependent upon environmental context.
Submitted By: Katelin Pearson
Herbaria and the wealth of specimens they contain are increasingly being used for research, education, and outreach, especially as millions of specimen records are digitized and made available through public data portals. This session provides a forum for sharing impactful and innovative uses of herbaria and specimen data, including novel research using digitized specimen data, new educational modules or approaches using herbarium specimens, efforts to augment existing data by leveraging new data sources or measurement techniques, and collaborative projects that bring institutions together around a collections-focused goal.