| Title | Atmospheric deposition and precipitation are important predictors of inorganic nitrogen export to streams from forest and grassland watersheds: a large-scale data synthesis |
| Abstract | Previous studies have evaluated how changes in atmospheric nitrogen (N) inputs and climate affect stream N concentrations and fluxes, but none have synthesized data from sites around the globe. We identified variables controlling stream inorganic N concentrations and fluxes, and how they have changed, 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 hypothesized that sites with greater atmospheric N deposition have greater stream N export rates, but that climate has taken a stronger role as atmospheric deposition declines in many regions of the globe. We found declining trends in bulk ammonium and nitrate deposition, especially in the longest time-series, with ammonium contributing relatively more to atmospheric N deposition over time. Among sites, there were statistically significant positive relationships between (1) annual rates of precipitation and stream ammonium and nitrate fluxes and (2) annual rates of atmospheric N inputs and stream nitrate concentrations and fluxes. There were no significant relationships between air temperature and stream N export. Our long-term data shows that although N deposition is declining over time, atmospheric N inputs and precipitation remain important predictors for inorganic N 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. |
| Source | Biogeochemistry (Dordrecht) 160 (2), pp. 219–241 |
| Keywords | Bulk nitrogen depositionLTERAtmospheric pollutionThroughfallWatershedWater quality |
| Journal | Biogeochemistry (Dordrecht) |
| Editor | Nijhoff/Junk, Boston, Paesi Bassi |
| Year | 2022 |
| Type | Articolo in rivista |
| DOI | 10.1007/s10533-022-00951-7 |
| Authors | Templer, P. H.; Harrison, J. L.; Pilotto, F.; Flores-Diaz, A.; Haase, P.; McDowell, W. H.; Sharif, R.; Shibata, H.; Blankman, D.; Avila, A.; Baatar, U.; Bogena, H. R.; Bourgeois, I; Campbell, J.; Dirnboeck, T.; Dodds, W. K.; Hauken, M.; Kokorite, I; Lajtha, K.; Lai, I-L; Laudon, H.; Lin, T. C.; Lins, S. R. M.; Meesenburg, H.; Pinho, P.; Robison, A.; Rogora, M.; Scheler, B.; Schleppi, P.; Sommaruga, R.; Staszewski, T.; Taka, M. |
| Text | 477474 2022 10.1007/s10533 022 00951 7 ISI Web of Science WOS 000827380500001 Bulk nitrogen deposition LTER Atmospheric pollution Throughfall Watershed Water quality Atmospheric deposition and precipitation are important predictors of inorganic nitrogen export to streams from forest and grassland watersheds a large scale data synthesis Templer, P. H.; Harrison, J. L.; Pilotto, F.; Flores Diaz, A.; Haase, P.; McDowell, W. H.; Sharif, R.; Shibata, H.; Blankman, D.; Avila, A.; Baatar, U.; Bogena, H. R.; Bourgeois, I; Campbell, J.; Dirnboeck, T.; Dodds, W. K.; Hauken, M.; Kokorite, I; Lajtha, K.; Lai, I L; Laudon, H.; Lin, T. C.; Lins, S. R. M.; Meesenburg, H.; Pinho, P.; Robison, A.; Rogora, M.; Scheler, B.; Schleppi, P.; Sommaruga, R.; Staszewski, T.; Taka, M. Boston Univ; Columbia Univ; Norwegian Inst Nat Res NINA; Univ Iberoamer; Senckenberg Res Inst; Nat Hist Museum Frankfurt; Univ Duisburg Essen; Univ New Hampshire; Univ Maryland; Hokkaido Univ; ILTER Informat Management Comm; Campus Univ Autonoma Barcelona; Univ Vienna; Forschungszentrum Julich; Univ Colorado; NOAA; US Forest Serv; Environm Agcy Austria; Kansas State Univ; Norwegian Inst Bioecon Res; Univ Latvia; Latvian Environm Geol Meteorol Ctr; Oregon State Univ; Natl Pingtung Univ Sci Technol; Swedish Univ Agr Sci; Natl Taiwan Normal Univ; Univ Sao Paulo; Northwest German Forest Res Inst; Univ Lisbon; CNR; Swiss Fed Inst Forest Snow Landscape Res; Univ Innsbruck; Inst Ecol Ind Area; Aalto Univ Previous studies have evaluated how changes in atmospheric nitrogen N inputs and climate affect stream N concentrations and fluxes, but none have synthesized data from sites around the globe. We identified variables controlling stream inorganic N concentrations and fluxes, and how they have changed, 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 hypothesized that sites with greater atmospheric N deposition have greater stream N export rates, but that climate has taken a stronger role as atmospheric deposition declines in many regions of the globe. We found declining trends in bulk ammonium and nitrate deposition, especially in the longest time series, with ammonium contributing relatively more to atmospheric N deposition over time. Among sites, there were statistically significant positive relationships between 1 annual rates of precipitation and stream ammonium and nitrate fluxes and 2 annual rates of atmospheric N inputs and stream nitrate concentrations and fluxes. There were no significant relationships between air temperature and stream N export. Our long term data shows that although N deposition is declining over time, atmospheric N inputs and precipitation remain important predictors for inorganic N 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. 160 Published version Articolo in rivista Nijhoff/Junk 0168 2563 Biogeochemistry Dordrecht Biogeochemistry Dordrecht Biogeochemistry Dordrecht Biogeochemistry. Dordrecht michela.rogora ROGORA MICHELA TA.P02.014.002 Impatto dei cambiamenti globali sugli ecosistemi acquatici |
