- ItemImaging Calamites: Methodologies of Investigating Carboniferous Period Plant Hydraulics(2023) Mamlin, Charles B.; Wilson, JonathanAnthropogenic climate change poses an imminent threat to humanity, and understanding how plants contribute to global climate homeostasis is paramount to mediating the effects of such change both today and for the future. Paleobotanical study, although largely undiscussed in modern discourse surrounding climate change, can provide key insights into how plants have uniquely acted as an interface between the biosphere and planetary environments throughout history. Extinct plants’ anatomical structures supply a window into the evolution of plant-level morphological traits, and environmental and climatic feedbacks through time. Measuring the dimensions of water transport cells (xylem) in extinct plants allows for the study of past hydraulic strategies, and yields insights into the history of how plant communities have responded to past episodes of climate change. During this project, we delve into the methodologies behind investigating the critical role that plant physiology has played in different planetary feedbacks throughout time. A subperiod of the Carboniferous Period — the Pennsylvanian SubPeriod (323–299 million years ago) — is of particular interest because this time period featured low concentrations of atmospheric carbon dioxide that resulted from atypical rates of organic carbon sequestration. Using light microscopy and scanning electron microscopy (SEM), we image the water transport cells of an extinct genus of Carboniferous land plant that was characteristic to swamp ecosystems and closely related to modern horsetails: Calamites. Comparing the anatomy of Calamites and other extinct taxa to modern structures can provide important context for the examination of how terrestrial plants adapt to environmental stress. These high-resolution images further illustrate the water transport morphology of Calamites at a cellular level, revealing details about its subcellular composition that can advance understanding of their ecological roles during a time of extreme climate change.
- ItemReturning the People to the land: An Exploration of Black Americans’ relation to the natural world in the past and present(2023) Graham, Ebony; Young, TaliaThis paper explores the relationship of Black Americans toward natural outdoor spaces, what histories and dynamics have informed this relationship, and exploring ways in which this relationship influences our foodways and culinary cultures. In this paper, I explore Black folks’ relationship with land before colonization and enslavement, examples of the systematic disenfranchisement of Black people from the natural world by white people, and Black resilience to this systematic disenfranchisement by returning to the land and embracing creativity in the cultivation and cooking of homegrown diasporic ingredients.
- Item“It’s the Pits!”: Imaging of Lepidophloios and Lepidodendron, Arborescent Lycopsid Tracheids(2023) Culton, Ella; Wilson, JonathanThe arborescent lycopsids Lepidophloios and Lepidodendron dominated the Middle-Pennsylvanian period, emblematic of the adaptations and vascular structure which allowed the tree lycopsids to thrive until the climatic shift of the Westphalian, bringing rise to the tree ferns. This study analyzed Lepidophloios specimen (West Mineral, KS) and an Unknown specimen (United Kingdom) using acid maceration, light microscopy, and scanning electron microscopy (SEM). Unexpectedly, the Lepidophloios specimen yielded many tracheid segments with circular border pits, rather than the anticipated scalariform pits. The Unknown specimen, which remains unidentified, yielded several promising fragments of scalariform pits. Under the scanning electron microscope only one scalariform pit was successfully identified and photographed. The tutorial and imagery developed from this study will contribute to future research of Lepidophloios and modelling the hydraulic conductance of arborescent lycopsids from the Carboniferous period.
- ItemClosed-Loop Composting at Haverford College: Proposal and Implementation Plan(2022) Edwards, Alexandra; Douglas, JoanneProposal for a Closed-Loop Composting System on Haverford's Campus
- ItemAnthropogenic Contamination in US Nearshore Waters: Analysis of Coastal Flooding Concerns and Nonpoint Pollution Risk Factors(2022) Kerns, Ellie; White, Helen K.Runoff from land introduces anthropogenic contaminants to nearshore marine environments impacting water quality and ecosystem health. The expansion of urban land area and associated urban population growth, without efforts to reduce urban runoff, threatens the health of nearshore waters. Due to sea level rise there will be a greater frequency of general coastal flooding and major flood events that can amplify this problem. This study explores 185 coastal counties within the 18 states of the United States that have coastal land area and the Atlantic and Gulf coasts. We looked at the occurrences of coastal flooding, storm surge, and tropical storms and hurricanes within each county. To identify areas of particular concern for increased runoff of anthropogenic contaminants, we cross-referenced each county's city structure, population growth, superfund sites, farmland percentage, and copper and coal mines. Overall, we found 33 counties with high flood concern and within that 6 counties that have high risk for increased anthropogenic contamination. Looking into the future, as the US continues to coastally urbanize and climate change continues to impact coastal waters, we will need to continue to monitor anthropogenic contamination of nearshore waters.