Biology Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2749
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Item The Role of Urban Agriculture in Baltimore Food Systems(2024) Mathews, Meghna Anjali; Zhang, Xin; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The United States is one of the most agriculturally productive countries; and yet, food insecurityremains a significant issue. Urban agriculture in Baltimore, Maryland should be studied further because of its potential to address food insecurity while overcoming systemic barriers created and embedded within food systems. While numerous previous studies have explored food insecurity, knowledge gaps still exist regarding how urban agriculture has influenced food accessibility, and how availability, cultural values of foods, etc. can be improved through increased production and distribution practices of fresher fruits and vegetables in Healthy Food Priority Areas. To address these knowledge gaps, we queried food insecure community members and urban farmers in Baltimore, Maryland to better understand the underlying factors that influence low fruit and vegetable consumption and how they can be mitigated through the establishment of urban agriculture. Urban farmers were interviewed in detail about their production and distribution patterns, and factors influencing the low consumption of fresh fruits and vegetables by community members in Baltimore. Food insecure individuals were asked about their food consumption habits and the accessibility of fruit and vegetables, their food purchasing behavior and related challenges, and community needs. Results indicate that while accessibility and availability are two main factors in fresh produce consumption, there are other important factors that might have received limited attention in existing literature. Our interviews revealed that income, cultural value, and a lack of knowledge in food preparation are key factors in low consumption and purchase of fresh fruits and vegetables. To address the underlying factors and improve the accessibility and availability of fresh produce to low-income communities, it is important to assess community needs and provide policy recommendations that can potentially enhance their nutrition. Ensuring access to individuals with limited resources is a critical component of advancing social justice.Item Nitrogen Uptake and Denitrification in Restored and Degraded-Urban Streams: Impacts of Organic Carbon and Integrated Stormwater Management(2015) Newcomer Johnson, Tamara Ann; Kaushal, Sujay S.; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Managing the N cycle and restoring urban infrastructure are major challenges especially in urban ecosystems. Organic carbon is important in regulating ecosystem function and its source and abundance may be altered by urbanization. My research focused on urban-degraded, restored, and forested watersheds at the Baltimore LTER in the Chesapeake Bay watershed. In Chapter 2, I investigated shifts in organic carbon quantity and quality associated with urbanization and ecosystem restoration, and its potential effects on denitrification at the riparian-stream interface. Denitrification enzyme assay experiments showed carbon was limiting in hyporheic sediments and variable carbon sources (grass clippings, decomposing leaves, and periphyton) stimulated denitrification differently. Evidence from stable isotopes, molar C:N ratios, and lipid biomarkers suggested that urbanization can influence organic carbon sources and quality in streams, which may have substantial downstream impacts on ecosystem services such as denitrification. In Chapter 3, I investigated whether stormwater best management practices (BMPs) integrated into restored and degraded urban stream networks can influence watershed N loads. I hypothesized that hydrologically connected floodplains and stormwater BMPs are “hot spots” for N retention through denitrification because they have ample organic carbon, low dissolved oxygen levels, and high residence time. I used reach-scale nitrogen mass balances, in-stream tracer injection studies, and 15N in situ denitrification to measure N retention in stormwater BMPs and their larger stream networks. There were high rates of in situ denitrification in both stormwater BMPs and floodplain features. Hydrologically connected floodplains can be important “hot spots” for N retention at a watershed and stream network scale because these areas likely receive perennial flow through the groundwater-surface water interface during both baseflow and storm events, while BMPs only receive intermittent flow associated with storm events. In Chapter 4, I conducted a literature review of N retention within hydrologically reconnected streams and floodplains. I reviewed 79 stream and floodplain restoration empirical studies from North America, Europe, and Asia and found that methods for measuring N retention varied considerably. I found many diverse strategies for promoting the ecosystem function of N retention in urban and agricultural watersheds.