Plant Science & Landscape Architecture Theses and Dissertations

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The kinetics and quantum yield of photophosphorylation in Anacystis nidulans (Richt.) Drouet
(1972) Owens, Olga v. H.; Krauss, Robert W.; Plant Physiology; Digital Repository at the University of Maryland; University of Maryland (College Park, MD)
The active metabolite, ATP, serves not only as a high energy intermediate but also as a controller of some enzymatic reactions. In plant cells, the larger part of the ATP is formed by photophosphorylation. In this paper the rates, the quantum yields, and the wavelength dependencies of photophosphorylation in the blue-green alga Anacystis nidulans are reported. A fluorometric method for determination of enzymatically produced NADPH from ATP was adapted for use on cell extracts. In the light, the ATP level was 0.15 to 0.25 µmoles/mg chl. In the dark, the ATP level was 70% of that in light. In both darkness and anaerobosis, the level was 20%. A return to the light restored the ATP level from both conditions. Dark, anaerobic cells were exposed to measured irradiancies of 710 nm and 620 nm. The rate of ATP formation was measured within the first few seconds and found to be directly proportional to absorbed intensity. Saturation of the rates occurred at an intensity one-tenth the optimum for oxygen production. Quantum requirements of 6-8 were similar for each of the two wavelengths. The system II inhibitor DCMU, had a greater effect at 620 nm that at 710 nm indicating an involvement of system II in photophosphorylation only at 620 nm. At low intensities and over long time periods white light failed to produce a saturating steady-state level of ATP indicating a simultaneous consumption of ATP. Measurements in short dark periods following marginal illumination showed consumption of ATP to be 2 to 4 times greater that production in weak light. Thus, the quantum requirement can be calculated to be 2. ATP formation, therefore, is not the limit ing factor in co2 fixation. The evidence is the high quantum yield of photophosphorylation and the unsaturation of co2 fixation at intensities at which ATP synthesis is saturated.
CREATING SPACE FOR NATURE RX AT HISTORICALLY BLACK COLLEGES AND UNIVERSITIES
(2023) Smith, Marci-Ann; Sachs, Naomi A; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
With the rising trend of mental health issues among young adults, many colleges are trying to establish an approach to combat those issues for the well-being of their students. One such approach is Nature Rx. Nature Rx is a program that encourages people, sometimes with an actual prescription, to spend time in nature in order to relieve stress and improve overall health. Nature Rx is a holistic way of addressing mental issues such as stress, anxiety, and depression that are prevalent among college students. The evidence is strong that time spent in and engaging with nature can improve mental and physical health. Colleges like Cornell University and University of Maryland College Park are taking advantage of their existing beautiful landscape as part of their Nature Rx program to help their students. Other schools are implementing this program and providing spaces for their students to find reprieve from the stresses of studies. However, there is a gap in the presence of Nature Rx programs at Historically Black Colleges and Universities (HBCUs). To date, no HBCU has a nature Rx program. This project seeks to fill that gap by using the University of Maryland Eastern Shore, an HBCU, as a case study to answer the following thesis question: “How could a Nature Rx design at the University of Maryland Eastern Shore, a Historically Black College and University, benefit the health and well-being of its students?”
ILLUMINATING PUBLIC SPACES THROUGH ARTFUL LIGHTING DESIGN: A RESPONSE TO THE PROPOSED ELEVATED SEAWALL ON STATEN ISLAND
(2023) Shteinberg, Debra; Sullivan, Jack; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This thesis explores the ways in which lighting can be used to create a memorable nocturnal experience that engages users and strengthens connections to their landscapes. Far more than functional, lighting is an art form that can be used to transform the very way we understand and experience our public spaces. Through the lens of lighting design, a redesign of the FDR Beach and Boardwalk is proposed in response to the building of the East Shore Seawall, a large-scale infrastructure project that will threaten the community’s ability to engage with this vital open space. Lighting is used to create spaces that allow for entertainment, education, and reflection, which will activate the site, providing legibility, enhance the nighttime experience, and create a sense of identity.
FROM HARM TO HOPE: REIMAGINING AN ABANDONED ASYLUM AS A SPACE OF REFLECTION, REJUVENATION, AND REJOICE
(2023) Reise, Matthew; Sullivan, Jack; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The Crownsville State Hospital opened in 1913 as the first and only mental institution in the state of Maryland to serve the Black community. After 91 years of operation rife with neglect, abuse, exploitation, and other acts of inhumanity, the hospital closed and has laid virtually abandoned since. In this thesis, I will propose ways of reactivating Crownsville’s historic campus through acknowledging the property’s horrific past, by providing support and amenities to the region’s most vulnerable individuals, and by creating space to celebrate the identity of communities who were historically persecuted on the grounds. I will explore the Crownsville campus through the lens of a cultural landscape, and attempt to balance the preservation of existing assets with the development of new community features.
GROWING STEWARDS – REIMAGINING A HISTORIC LANDSCAPE AS A VENUE FOR CLIMATE CHANGE AWARENESS THROUGH EDUCATION, ADAPTATION, AND PLAY
(2023) Callahan, Erin O'Dell; Sullivan, Jack; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Historic landscapes are an important part of our collective heritage. They provide a window to the past, offering narratives of our origins and how our relationships with nature have changed over time. Such landscapes receive historic treatments, including preservation, to ensure they are suspended in their period of significance. However, this static approach is no longer effective in protecting and communicating the heritage historic landscapes were intended to share: new approaches must be considered to contend with the dynamism of both nature and culture and ensure the health of these landscapes for generations to come. As climate change is the biggest threat to such landscapes, this thesis aims to explore how climate adaptive strategies can be responsive to both the historic and contemporary context of Meridian Hill Park: a cultural landscape that has been on the National Historic Register since 1994. It will focus specifically on providing meaningful experiences for children in the landscape, as a changing climate and environment is what they will inherit.

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