2021 journal article
Characterizing ambient nutrient concentrations and potential warning levels for surface water in natural forested wetlands in the Piedmont and Coastal Plain of North Carolina, USA
ECOLOGICAL ENGINEERING, 172.
author keywords: Wetlands; wetland water quality; nutrients; ambient water quality
UN Sustainable Development Goal Categories
6. Clean Water and Sanitation
(OpenAlex)
15. Life on Land
(Web of Science)
Source: Web Of Science
Added: October 4, 2021
Nearly thirty years ago the U.S. EPA directed states to begin developing water quality standards specific to wetlands; however, progress has been limited. This study presents an overview of ambient wetland water quality and the first step towards the development of numeric nutrient standards for forested wetlands in North Carolina. Water quality samples were collected in 16 natural wetlands across the state for three years. The sites span a range of anthropogenic disturbance. The data was combined with historical data collected at these and other sites from 2005 to 2013. Concentration levels in wetlands without significant anthropogenic disturbance are likely higher than streams for TN, TP, similar for NH 4 + , and likely lower than streams for NO 3 – -N. A method developed by the U.S. EPA to establish reference levels was modified to define draft nutrient warning levels that may indicate anthropogenic impacts. These warning levels were calculated as 0.06 mg/L, 0.14 mg/L, 0.34 mg/L and 2.8 mg/L for NO 3 – -N, NH 4 + -N, TP and TN, respectively. NO 3 – -N and NH 4 + -N concentrations were the best indicators of disturbance. Overall, despite the limitations imposed by the sampling frequency and inherent variability in wetland ecosystems, this research methodology presents a reasonable first attempt at defining nutrient warning levels for undisturbed natural forested wetlands in N.C., and may serve as a starting point in developing numeric nutrient criteria for wetlands. • A first step towards the development of nutrient concentration standards for natural wetlands. • Wetland standard concentration levels are likely higher than streams for TN, TP, similar for NH 4 + -N, and lower for NO 3 N. • Proposed warning levels for NO 3 – N and NH 4 + -N were the best indicators of disturbance. TN, ON, and TP were not robust indicators. • Results could help identify disturbance in natural forested wetlands in North Carolina.