Two of the most widespread ecological issues are 1) the eutrophication of aquatic ecosystems and 2) the shift in global carbon reservoirs due to accelerated greenhouse gas (GHG) emissions. Excess nitrogen (N) is a growing management concern for many waterbodies in Florida and beyond. Stormwater runoff systems are tasked with the removal of N from runoff prior to discharge into receiving waters. Engineered infiltration medias, such as Biosorption Activated Media (BAM), are considered nutrient remediation technologies aimed at enhancing nutrient removal to meet water quality standards. However, literature suggests some native soils may perform better than BAM. This study examines the properties of native soils that can enhance N removal through denitrification, without contributing additional internal N through soil organic matter (SOM) mineralization. Results suggest that native soils performed better than BAM at removing N. Results suggest optimal N removal efficiency at intermediate SOM content under simulated stormwater conditions. Results suggest that hydrology and soil composition highly impact net N removal rates and BAM lacked N cycling activity even after soils were inoculated with a microbial community. Mineralization of SOM leads to land–atmosphere carbon exchange that can exacerbate climate change by increasing atmospheric GHG concentrations. The presence of mineral-associated organic matter (MAOM) and formation of water stable aggregates (WSA) within soils can slow mineralization by reducing microbial accessibility to SOM. This study experimentally tests if C protection of varying degrees (WSA and MAOM) can be stimulated to form in high organic wetland soils treated with C amendments of varying lability and altered hydrology under laboratory conditions. WSA formation was greater in soils exposed to fluctuating water level and MAOM content was highest in soils amended with labile C substrates. Stimulating the formation of MAOM in vulnerable C rich soils may be a pathway to minimize SOM mineralization in wetlands.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd2020-2789 |
| Date | 15 August 2023 |
| Creators | Nitsch, Chelsea |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations, 2020- |
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