Abstract

Wetlands are essential environments for the regulation of the nitrogen cycle by the rapid conversion of different forms of nitrogen at the border of land and water. This study examines the biogeochemical processes that describe nitrogen cycling by nitrification, denitrification and ammonification processes, and also the role of wetlands in nutrient retention, water quality improvement, and greenhouse gas (GHG) emissions mitigation. This study examines the role of wetlands in the regulation of nitrogen, and the conversion of nitrogen by removal of excess nitrogen that can lead to eutrophication. For the study, a mixture of field sampling, hydrological monitoring, and microbial monitoring were utilized to study wetland nitrogen cycling across different hydrological and seasonal conditions. The study reveals that the nitrogen cycles change in a seasonal pattern and are driven by hydrological conditions including water-level, ground water flow, and tidal cycles. Sites were also monitored and sampled for nitrate and those that had higher nitrates were considered at risk for eutrophication. Some of the statistical analyses emphasized the role of microbes on the control of nitrogen cycling and the ways in which hydrological conditions modulate microbial processes on nitrogen cycling. Ammonium concentrations were measured at 0.45 mg N/L while the corresponding standard deviation was 0.15. For nitrate, the measured average was 1.15 mg N/L and had a higher standard deviation (0.30) meaning the nitrate was higher in its fluctuating external conditions. The study identifies the interactions between hydrological conditions, microbial growth, and nitrogen cycling in wetlands describing its resilience to the changed environmental conditions. The results can improve the management of wetlands, especially for restoration that aims towards the elevation of nitrogen removal and enhancement of the environmental conditions.

Keywords: Nitrogen cycling, Wetland ecosystems, Land-Water interface, Nitrification, Denitrification, Nutrient dynamics, Biogeochemical processes