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Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use |
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| Authors: | Miriam Hurkuck Christian Brümmer Karsten Mohr Oliver Spott Reinhard Well Heinz Flessa Werner L Kutsch |
| Affiliation: | 1. Thünen Institute of Climate‐Smart Agriculture, Federal Research Institute for Rural Areas, Forestry and Fisheries, Braunschweig, Germany;2. Landwirtschaftskammer Niedersachsen, Oldenburg, Germany;3. Department of Soil Physics, Helmholtz Centre for Environmental Research ‐ UFZ, Halle, Germany;4. Integrated Carbon Observation System (ICOS), University of Helsinki, Headoffice, Finland |
| Abstract: | We applied a 15N dilution technique called “Integrated Total Nitrogen Input” (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot?1) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot?1. Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha?1 yr?1. Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5–10 kg N ha?1 yr?1. |
| Keywords: | 15N isotope dilution technique biomonitoring critical load Eriophorum vaginatum integrated total nitrogen input Lolium multiflorum nitrogen deposition ombrotrophic bog |
