International Long-Term Ecological Research Network (ILTER) atmospheric deposition and stream nitrogen synthesis

Templer Pamela H. 1, Harrison Jamie L. 1,2, Pilotto Francesca 3, Flores-Díaz Andri 4, Haase Peter 5,6, McDowell William H. 7, Sharif Rahat 8, Shibata Hideaki 9, Blankman David 10, Avila Anna 11, Baatar Undrakh-Od 12, Bogena Heye Reemt 13, Bourgeois Ilann 14, Campbell John 15, Dirnböck Thomas 16, Dodds Walter K. 17, Hauken Marit 18, Kokorite Ilga 19, Lajtha Kate 20, Lai Iling L. 21, Laudon Hjalmar 22, Lin Teng-Chiu 23, Lins Silvia Rafaela M. 24, Meesenburg Henning 25, Pinho Pedro 26, Robison Andrew 7, Rogora Michela 27, Scheler Birte 25, Schleppi Patrick 28, Sommaruga Ruben 29, Staszewski Tomasz 30, Taka Maija 31

1 Department of Biology, 5 Cummington Mall., Boston University, Boston, MA 02215, USA
2 Lamont-Doherty Earth Observatory of Columbia University, 306C Oceanography, 61 Route 9W, 17 Palisades, NY 10964, USA 18
3 Environmental Archaeology Lab, Department of Historical, Philosophical and Religious studies, 19 Umeå University, Umeå, Sweden 20
4 Transdisciplinary Center for Sustainability, Universidad Iberoamericana, Ciudad de México- 21 Tijuana. Prol. Paseo de la Reforma 880, Lomas de Santa Fe, Mexico City 01219, Mex. 22
5 Department of River Ecology and Conservation, Senckenberg Research Institute and Natural 23 History Museum Frankfurt, Gelnhausen, Germany 24
6 Faculty of Biology, University of Duisburg-Essen, Essen, Germany 25
7 Department of Natural Resources and the Environment, University of New Hampshire, Durham, 26 NH, 03824 27
8 Department of Environmental Science and Technology, University of Maryland - College Park, 28 Maryland, USA 29
9 Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan 30
10 ILTER Information Management Committee, Jerusalem, Israel 31
11 CREAF, Campus Universitat Autònoma de Barcelona, E08193, Bellaterra, Spain 32
12 Department of Botany and Biodiversity Research, Division of Conservation Biology, Vegetation 33 Ecology and Landscape Ecology, University of Vienna, Rennweg 14, 1030 Vienna Austria 34
13 Agrosphere Institute (IBG-3), Forschungszentrum Jülich, 52425 Jülich, Germany 35
14 Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, 36 Boulder, CO, USA and NOAA Chemical Science Laboratory, Boulder, CO, USA 37
15 US Forest Service, Northern Research Station, Durham, New Hampshire, USA 38
16 Environment Agency Austria, A-1090 Vienna, Austria 39
17 Division of Biology, Kansas State University, Manhattan, Kansas, USA 40
18 NIBIO, Norwegian Institute of Bioeconomy Research, Ås, Norway 41
19 Institute of Biology, University of Latvia, Jelgavas iela 1, Riga, LV-1004, Latvia and Latvian 42 Environment, Geology and Meteorology Center, Maskavas iela 165, LV-1019, Riga, Latvia 43
20 Department of Crop and Soil Sciences, Oregon State University, Corvallis OR, USA 44
21 Graduate Institute of Bioresources, National Pingtung University of Science and Technology, 1 45 Shuefu Rd, Neipu, Pingtung 912, Taiwan 46
22 Dept. Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 47 Umeå, Sweden 48
23 Department of Life Science, National Taiwan Normal University, Taipei, Taiwan 49
24 Center for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, Brazil. 50
25 Northwest German Forest Research Institute, Grätzelstr. 2, 37079 Göttingen, Germany 51
26 Centre for Ecology, Evolution and Environmental Changes, Universidade de Lisboa, Lisbon, 52 Portugal 53
27 CNR Water Research Institute, L.go Tonolli 50, I 28922 Verbania Pallanza, Italy 54
28 Swiss Federal Institute for Forest, Snow and Landscape Research, Zürcherstr. 111, CH-8903 55 Birmensdorf, Switzerland 56
29 Department of Ecology, University of Innsbruck, 6020 Innsbruck, Austria 57
30 Integrated Monitoring Department, Institute for Ecology of Industrial Area, Katowice, Poland 58
31 Water and Environmental Engineering Research Group, Aalto University, P.O. Box 15200, FI- 59 00076 Aalto, Espoo, Finland

Environmental Data Initiative edi.1066.1 (2022)

DOI: 10.6073/pasta/a815f37b4aaa7cf56337e6451a2e2444


We identified variables controlling stream nitrogen concentrations and fluxes, and how they have changed over time, by synthesizing 20 time series ranging from 5 to 51 years of data collected from forest and grassland dominated watersheds across Europe, North America, and East Asia and across four climate types (tropical, temperate, Mediterranean, and boreal) using the International Long-Term Ecological Research Network. We found declining trends in bulk ammonium and nitrate deposition, with ammonium contributing significantly more to atmospheric nitrogen deposition over time. Among sites, there were significant positive relationships between (1) precipitation and stream ammonium and nitrate fluxes and (2) atmospheric nitrogen inputs and stream nitrogen concentrations and fluxes. There were no significant relationships between air temperature and stream nitrogen export. Our long-term data shows that although nitrogen deposition is declining over time, atmospheric nitrogen inputs and precipitation remain the main predictors for nitrogen exported from forested and grassland watersheds. Overall, we also demonstrate that long-term monitoring provides understanding of ecosystems and biogeochemical cycling that would not be possible with short-term studies alone. Acknowledgements: We thank the organizers and funders of the ILTER Nitrogen Initiative Training Course and Workshop in Hokkaido, Japan in June 2016, which brought together many of the participants in this project. Templer was supported by a US National Science Foundation LTER grant NSF DEB 1637685. McDowell was supported by US National Science Foundation LTER grant NSF DEB 1831592. We are grateful to the EU Horizon 2020 funded eLTER PLUS project (Grand Agreement No. 871128) for financial support to Haase and Dirnböck. Dirnböck was also funded by the LTER-CWN project (FFG project number 858024). This study was partly supported by the Research Initiative Grants of the ILTER, Grants-in-Aid for Scientific Research (17H03833), and Research Institute for Humanity and Nature (RIHN; a constituent member of NIHU) Project No. 14200156. Sharif was supported by NRT-INFEWS: UMD Global STEWARDS (STEM Training at the Nexus of Energy, WAter Reuse and FooD Systems) that was awarded to the University of Maryland School of Public Health by the National Science Foundation National Research Traineeship Program, Grant number 1828910. The monitoring of the Svartberget site in Sweden was funded by the SITES program from the Swedish Research Council. The monitoring of the Volbu Nyhaga site in Norway was part of JOVA - The Norwegian Agricultural Environmental Monitoring Programme, financed by the Ministry of Agriculture and Food. Lajtha was supported by NSF grants DEB-1257032 and DEB-1440409 to the H. J. Andrews Long Term Ecological Research program. The data collection in the Wüstebach catchment was supported by TERENO (Terrestrial Environmental Observatories) funded by the Helmholtz-Gemeinschaft. We thank the “Hessisches Landesamt für Naturschutz, Umwelt und Geologie” for providing data from the Rhine-Main-Observatory. I.Kokorīte was supported by the University of Latvia grant No. AAp2016/B041//Zd2016/AZ03. We thank the Latvian Environment, Geology and Meteorology Center for providing the monitoring data for Latvian site. Anna Avila was supported by Spanish Ministry of Science projects CGL2017-84687-C2-2-R and CGL2009-13188-C03-01. We thank the Tyrolean Alps Long-Term Sociological Ecological and Research (LTSER, Austria) and R. Psenner and S. Morales for helping with data for Piburger See. Data from Hubbard Brook were supported by the National Science Foundation (DEB-1907683) and US Forest Service, Northern Research Station. A. Robison was supported by US National Science Foundation LTER grant NSF OCE 1637630. W. Dodds was supported by NSF DEB 2025849. Observations at Lange Bramke site were funded by the Ministry of Nutrition, Agriculture and Consumer Protection of Lower Saxony under the Permanent Soil Monitoring Programme. The Krofdorf site was funded by the Hessian Ministry of Environment, Climate Protection, Agriculture and Consumer Protection under the “Waldökosystemstudie Hessen”. SRM Lins was supported by the São Paulo Research Foundation - FAPESP, grant number 2012/20377-9. Long-term monitoring at Lake Maggiore (LTER site EU-IT08-001-A) was funded by the International Commission for the Protection of Swiss-Italian waters (CIPAIS).

Keywords: bulk nitrogen deposition, LTER, atmospheric pollution, throughfall, watershed, water quality