Browsing by Author "Wilson, Jonathan"
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- Item"A River Filled With Ghosts:" The Massacre River in Diasporic Memory(2024) Rodriguez-Gomez, Alex; Wilson, JonathanThis paper revisits the memory of the 1937 Massacre of Haitians, Afro-Dominicans, and rayanos in the Dominican borderlands in light of recent increased border militarization by reading for representations of the Massacre River in Freddy Prestol Castillo’s El Masacre se pasa a pie, Edwidge Dantica’s “Nineteen Thirty Seven” and Roxane Gay’s “In the Manner of Water or Light.” I argue that the Massacre River represents multiple contradictory meanings – both a border/boundary and a threshold, a place that generates both life and death – but ultimately in diasporic memory exists as a place for necessary reckoning with the legacies of colonialism. I also argue for the continued study of river-borders in the context of Black diasporic studies and border studies, as an expansion of theories related to the Black Atlantic.
- ItemAcclimation of Ginkgo biloba Photosynthetic Biochemistry Under Elevated Carbon Dioxide: Paleo-proxy and Conservation Consequences(2021) Dougherty, James Fitzmyer; Wilson, JonathanClimate change poses an enormous threat to the world's ecosystems (Shukla et. al 2019). As a result, it is important to evaluate the ecological consequences of other climates in Earth's history. A valuable way to approximate paleo-CO2 concentrations is by using plant proxies, such as the Ginkgo biloba stomatal index - paleo-CO2 model (Barlcay and Wing 2016). To determine the reliability of G. biloba as a paleo-CO2 proxy, it is necessary to understand whether G. biloba photosynthetic biochemistry acclimates to elevated CO2. If the biochemistry is significantly different than it is under ambient conditions, researchers will need to reassess the model. We planted three ages of G. biloba in open-top chambers with different CO2 concentrations, measured photosynthetic data using a Li-cor 6400XT, and calculated biochemical parameters utilizing the Plantecophys package in R. These results suggest that the G. biloba paleo-CO2 proxy should not need major modification, since a change in Jmax is less disruptive than a change in Vcmax.
- ItemForest Restoration: How History and Culture Shape Restoration in the Wissahickon Area(2024) Argueta-Roman, Adelma; Wilson, JonathanThis capstone project discusses the history of the Wissahickon Valley, and the restoration efforts that maintain the natural splendor of the area. From the settlement of the Lenni-Lenape to today, the Wissahickon forests have undergone many changes and anthropogenic stresses. Today, the forest is recovering with the help of non-profit groups, volunteers, and funds from governmental institutions. The overall goal has been to increase native biodiversity, decrease invasive exotic plants, and maintain a functional space for Philadelphia residents. I will discuss how life history alongside the current culture of biking, deer culling opposition, and lack of funding for parks have impacted how restoration works in the Wissahickon Valley. Having grown up in the Wissahickon Valley, I have a deep appreciation for the area. As a biology-environmental studies double major, I have also been interested in the conservation and restoration of natural spaces that have been negatively affected by anthropogenic actions. When the opportunity to intern with the Wissahickon Restoration Volunteer (WRV) non-profit group came, I was able to take my experience from my classes and supplement it with hands-on learning. While WRV taught me about logistical matters concerning restoration under high disturbance, I was able to grow my skills in measuring trees to determine growth rates in one of the sites, which are essential in understanding how restored areas are progressing. This capstone project gave me the opportunity to learn more about restoration in a way that tied theory with practice. Urban forest restoration has the responsibility of upholding ecosystems and public health, making it an extremely important effort.
- ItemHold The Salt: Effects Of Road Salt On Freshwater Systems In The Delaware River Basin(2024) Korgen, Jessica; Wilson, JonathanRoad salt has been effectively used to combat icy roads in the United States for nearly 100 years, causing an 85% reduction in vehicular accidents (Godwin, Hafner, and Buff 2003; Hintz, Fay, and Relyea 2022; Kuemmel and Hanbali 1992; Mullaney et al. 2009; Usman, Fu, and Miranda-Moreno 2010). As urbanization has increased, road salt use has skyrocketed, with application tripling in just the last half century (Dugan 2017; Hintz et al. 2022; Kaushal et al. 2005). The environmental consequences of NaCl on freshwater ecosystems has become increasingly apparent in recent years. Elevated salinity levels have been found to have an enormous impact on organisms that rely on freshwater bodies, especially those of lower trophic levels, which has a ripple effect across the whole ecosystem (Arnott et al. 2020; Hintz and Relyea 2017). Several species integral to the food web living in environments impacted by road salt face higher mortality rates, lower reproduction rates, reduced growth, and behavioral and physical abnormalities (Collins and Russel 2009; Hintz and Relyea 2017; Arnott et al. 2020). Four streams in the Delaware River Watershed were studied to determine the effects of road salt on their ecosystems. The chloride levels of each stream were monitored over the months of January and February 2024. Spikes in chloride concentrations were correlated with winter storms and road salt runoff. Baseflow conditions for many of the streams hovered around or above US EPA chronic chloride toxicity levels. First flushes following winter storms rose above acute toxicity levels, raising concern for the organisms that live in and rely on the streams. The possible effects of these elevated salinity levels are analyzed, and road salt alternatives and mitigation strategies are discussed.
- 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.
- 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.
- ItemLife in the Carboniferous Coal Swamp Forests: Reconstructing the Paleoecophysiology of the Extinct Horsetail Sphenophyllum(2024) Wagner, Sophia; Wilson, JonathanDuring the Carboniferous Period, there was a radiation of diversity in early plants that were well preserved for study due to the conditions of the Carboniferous coal swamp forests. Studying the coal balls gives scientists insight into the ecosystems of the past. Collaborations with paleoclimate scientists have allowed paleobotanists to line up flora abundances with climatic trends. During the Middle and Late Pennsylvanian period, there were five major intervals of climatic shifts from wet to dry ecosystems and, by the second dry interval at the Late Westphalian D early Stephanian, major plant extinctions took place as the swamp biomes became drier. This paper aims to give context into the species that inhabited the coal swamps and how the ecosystem shifted throughout the period. On a plant scale level, this paper also aims to examine the morphological properties of these Carboniferous plants that particularly make them vulnerable or resistant to the reductions in water availability. This targeted morphological research focuses on a specific understory horsetail genus Sphenophyllum. Sphenophyllum is a particularly unique plant due to its large, wide tracheids and density of bordered pits throughout the xylem making the plant extremely hydraulically conductive while also prone to cavitation. In understanding these plants on a community scale and also an individual morphological scale, we can begin to better understand the past ecosystems and predict how certain plants will respond to climate change in the present and future.
- ItemLive Fast, Die Young: Examining Hydraulic Conductivity Of The Extinct Lepidophloios And Extant Wollemia Nobilis(2024) Korgen, Jessica; Wilson, JonathanThe climate is changing at a scale never before seen by humans, and it is impossible to anticipate with certainty how these changes will affect the planet. The best way to attempt to predict how species and ecosystems will respond to our ever-evolving climate is to look to the past. Paleobotany—the study of plant fossils—can inform us about the environment in deep time and how plants previously interacted with, responded to, and influenced a changing climate. The Carboniferous period is the most recent climate parallel we have to today. Although the world looked very different 300 million years ago, with the supercontinent Pangea and so-called “primitive” plants dominating the Earth, there were several similarities to the modern climate. Carboniferous CO 2 fluctuations were within the range anticipated for the twenty-first century and, like we are seeing today, these variations in atmospheric CO 2 were associated with large decreases in sea ice volume, rising sea levels, and the cyclical restructuring of the planet's most extensive tropical forests (Montañez et al., 2016). This was also the last time the planet had complete deglaciation, a phase that we are currently on the trajectory for, so Carboniferous floral transitions during its glacial-interglacial periods could provide insight for what is to come. Several Carboniferous plants are reviewed in relation to their hydraulic efficiency and safety, providing insight to their plant function and the environments they inhabited. An important factor in the hydraulic capacities of plant fossils is the size, shape, and porosity of their pit membranes: the permeable barrier separating xylem cells which water passes through. A larger, more porous pit membrane allows water to pass through the plant quickly while a smaller pit membrane better protects the plant from the entrance of gas and possible embolism. Arborescent lycophytes (lycopsids)—which dominated the first 20 million years of the Carboniferous—are analyzed in particular. Hydraulic elements from lycopsid fossils are measured and considered in the context of the biomes they occupied. The extant Wollemi pine is also measured to contrast with the extinct lycopsid. Consequences for plants with low hydraulic safety when the Carboniferous climate changed and implications for modern plants are discussed.
- ItemQuilting Ecologies: Pennsylvania Tree Memorial Quilt Project(2024) Wagner, Sophia; Wilson, JonathanClimate change is altering entire communities, ecosystems, and entire biomes in a variety of devastating ways and the question still remains–how do we get people to care? Scientists are notoriously bad at communicating their findings and ideas and discussions about climate change have a tendency to end in apathy or anxiety that is not conducive to action. For this project, I propose that art can and should be utilized as a means to shift the conversations about climate change to allow people to feel, think, and act in ways that science alone cannot. I have created a memorial quilt of Pennsylvania tree species that are specifically vulnerable to climate change to highlight some of the culturally, historically, and ecologically important species that may not be on this land in fifty to one hundred years due to the drastic shifts in climate and all the byproducts of such effects. Yet the purpose of this project is not just to grieve the potential loss we will face, but to kindle reflection, discussion, and action towards protecting the biodiversity that defines our landscapes. In this supplementary paper, I expound on the ideas of communicating climate change and the advantages to utilizing art as the platform for social change. Additionally, I look specifically at how quilts have been used in the past as a means towards social justice and the history and meaning that quilts hold. I also delve into my specific quilt piece, examining climate change’s effect on native Pennsylvania tree species and each individual tree.
- ItemUnderstanding Traditional Chinese Herbal Medicine in the 21st Century: Case-study of Longdan Xiegan Tang(2024) Chen, XingZhi; Wilson, JonathanTraditional medicine (TM) is a fluid system of understanding the relationship of the human body, disease, and materia medica which has changed throughout centuries with the rise and fall of dynasties, empires, social reformation, and cultural revolutions. This project aims to develop a better understanding of one branch of TM, traditional Chinese herbal medicine (TCHM) in the 21st century. As the popularity of TCHM and herbal supplements are rising in more wealthy, developed countries in the West, it is important to understand the history and origins behind the development and accumulation of this knowledge. The introduction and background section explore the Orientalist and essentialist implications of official language about TM from organizations like the World Health Organization (WHO). To contextualize TM and TCHM in the 21st century, the background also describes the inability of current legal frameworks to protect traditional knowledge and medicine from exploitative practices in the post-colonial era. The second section, titled “Historical Context,” identifies some of the historical literature and classical Chinese Pharmacopeia, with a focus on Bencao Gangmu, Compendium of Materia Medica, or Great Pharmacopoeia by Li Shizhen, and discusses the process of compiling herbology and natural history. This section also describes the significant change in TCM during the Chinese Cultural Revolution of the late 1900s. The methods section describes the process of interviewing TCM practitioners, visiting and contacting local apothecaries, collecting literature, and documenting and translating interviews for this project. Lastly, the discussion section reflects on the interviews, conversations, and archival work done to acknowledge the complexity of how TCM is perceived in the 21st century due to the ongoing impacts of orientalism, essentialism, and empiricism. Additionally, Longdan Xiegan Tang (LDXGT) is used as a case-study to understand the usage of plants and plant material in TCHM, the paper describes the ethnobotany, morphology, and pharmacology of each specific component in the prescription.