Nutrient dynamics and eutrophication in U.S. wetlands: investigating the role of total phosphorus, nitrogen, and other water quality parameters

Assel Mukhamedyarova

Bakalářská práce

Abstract:

Eutrophication impacts wetland ecosystems through nutrient enrichment mainly from excessive phosphorus and nitrogen, which affects biodiversity and ecosystem services as well as water quality. This research focuses on nutrient dynamics by analyzing total phosphorus (TP), total nitrogen (TN), along with associated water quality parameters in multiple wetland systems across the United States. The research relies on data from the 2021 National Wetland Condition Assessment and uses statistical analysis and spatial interpolation methods (kriging) and regression modeling to study wetland nutrient patterns and environmental controls. The research shows wide variations in nutrient amounts, with TP concentrations ranging from 0.01 to 0.32 mg/L and TN from 0.4 to 3.8 mg/L, while revealing important relationships between TP and TN with chlorophyll-a (r = 0.72), as well as dissolved oxygen and turbidity and dissolved organic carbon and additional ecological indicators. The geospatial examination reveals major eutrophication hotspots, particularly in the Midwestern and Southeastern regions, where TP levels frequently exceeded 0.10 mg/L. The research implements trophic state indices modified for wetlands, which shows that phosphorus-based nutrient loading does not match chlorophyll-a responses: 36% of wetlands were classified as eutrophic based on TP, compared to only 22% based on chlorophyll-a, reflecting complex nutrient limitation scenarios. Analysis of seasonal and yearly variations in nutrient retention showed that hydroperiod changes, together with severe weather conditions such as heavy rainfall and drought periods, create essential fluctuations. The regression model analysis demonstrates how environmental factors including water temperature, conductivity, and landscape composition play a major role in predicting nutrient behavior, explaining 48% of TP and 42% of TN variability (adjusted R²). The predictive knowledge gained enables researchers to create specific strategies for reducing nutrients. The results demonstrate that effective eutrophication mitigation requires management strategies which account for wetland-specific conditions, including spatial patterns, nutrient ratios, and hydrological processes. The study brings fresh understanding to wetland nutrient cycling mechanisms and ecological relationships, which enables improved predictive nutrient management models and directs specific ecological restoration approaches to preserve wetland ecosystem functionality and resilience in the context of growing human activities and climate change.

Keywords

eutrophication, wetlands, U.S., total phosphorus, total nitrogen

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 31. 3. 2026

Obhajoba závěrečné práce

• Vedoucí: Mgr. Pavla Kovaláková, Ph.D.
• Oponent: Miroslav Jonáš, externi

Česká zemědělská univerzita v Praze

Fakulta životního prostředí

Bakalářský studijní program:
Environmental Data Science