Relationship between the natural abundance of soil nitrogen isotopes and condition in North Dakota wetlands. (January 2016)

• Record Type: Journal Article
• Authors: Meyers, Lindsey M.; Nahlik, Amanda M.; DeKeyser, Edward S.
• Is Part Of: Ecological indicators. Volume 60(2016)
• Page Start: 394
• Page End: 401
• Publication Date: 2016-01
• Subjects: National Wetland Condition Assessment (NWCA) -- N -- Stable isotopes -- Wetland assessment -- δ15N -- Floristic Quality Index (FQI); Environmental monitoring -- Periodicals; Environmental management -- Periodicals; Environmental impact analysis -- Periodicals; Environmental risk assessment -- Periodicals; Sustainable development -- Periodicals; 333.71405
• DOI: 10.1016/j.ecolind.2015.06.042
• Languages: English
• ISSNs: 1470-160X

Abstract

Highlights: The natural abundance of nitrogen isotopes (δ 15 N) in wetland soils was measured. Soil δ 15 N was compared with wetland assessment data. Soil δ 15 N reflected land use and wetland condition. Nitrogen isotopes may be useful for measuring wetland condition and biological processes. Abstract: A statewide condition assessment of North Dakota wetlands in the summer of 2011 was conducted as part of the U.S. Environmental Protection Agency's National Wetland Condition Assessment (NWCA). Two other wetland condition assessments, the Index of Plant Community Integrity (IPCI) and North Dakota Rapid Assessment Method (NDRAM), were also completed at each wetland. Previous studies have identified how the distinct signatures of stable isotopes can be used to determine different land uses, anthropogenic impacts, nutrient cycling, and biological processes. To evaluate if these relationships existed in northern prairie wetlands, the data collected from the wetland assessments were compared with the natural abundance of soil nitrogen (δ 15 N) isotopes. Wetland soil δ 15 N was significantly higher (isotopically heavier) in wetlands surrounded by cropland compared to those surrounded by idle or grazed/hayed grasslands, possibly reflecting anthropogenic impacts and multiple nitrogen sources. Soil δ 15 N was significantly correlated with floristic quality, IPCI scores, NDRAM scores, and average buffer width, indicating that soil δ 15 N values may be representative of wetland condition. Soil δ 15 N exhibited significant differences among wetland types, although limited sample sizes of certain wetland types may have affected this result. Additional studies on the natural abundance of wetland soil isotopes need to be performed in northern prairie wetlands. This study is the first step in exploring the potential applications of wetland soil nitrogen isotopes regarding wetland assessment and surrounding land use and provides important insight for future studies.