Biogeochemical Hot Spots and Hot Moments at the Interface of Terrestrial and Aquatic Ecosystems

McClain, Michael E.; Boyer, E. W.; Dent, C. Lisa; Gergel, Sarah E.; Grimm, Nancy B.; Groffman, Peter M.; Hart, Stephen C.; Harvey, J. W.; Johnston, Carol A.; Mayorga, Emilio; McDowell, William H.; Pinay, Gilles

doi:10.1007/s10021-003-0161-9

Cited by 1,939 publications

(1,526 citation statements)

References 84 publications

Supporting

Mentioning

1,482

Contrasting

Unclassified

Order By: Relevance

“…In this respect, for a reasonable extrapolation to a larger area, it is important to know to what extent data should be collected at the field scale. Hot spots are recently identified as of major importance in quantifying process rates and gas fluxes in many ecosystems (McClain et al 2003). Therefore, based on numerous studies all over the world, the interface zone of aquatic and terrestrial ecosystems, such as littoral zones or riparian zones, has been regarded as hotspots of N 2 O fluxes (Groffman et al 2000;Hefting et al 2003;Huttunen et al 2003b;Dhondt et al 2004;Hernandez and Mitsch 2006;Ullah and Zinati 2006;Wang et al 2006).…”

Section: Discussionmentioning

confidence: 99%

Nitrous oxide fluxes from the littoral zone of a lake on the Qinghai-Tibetan Plateau

Chen

Wang

et al. 2011

Environ Monit Assess

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Nitrous oxide fluxes from the littoral zone of a lake on the Qinghai-Tibetan Plateau

Chen

Wang

et al. 2011

Environ Monit Assess

View full text Add to dashboard Cite

“…Observed high N retention rates in urban watersheds have led to an effort to identify specific locations within watersheds that support high rates of N retention, so-called "hotspots"(-sensu McClain et al 8 ). Terrestrial ecologists have focused largely on the role of residential landscapesyardsas potential hotspots, 9−11 whereas aquatic ecologists have studied streams and stormwater infrastructure features as sites of N removal.…”

Section: ■ Introductionmentioning

confidence: 99%

Sources and Transport of Nitrogen in Arid Urban Watersheds

Hale

Turnbull

Earl

et al. 2014

Environ. Sci. Technol.

View full text Add to dashboard Cite

Urban watersheds are often sources of nitrogen (N) to downstream systems, contributing to poor water quality. However, it is unknown which components (e.g., land cover and stormwater infrastructure type) of urban watersheds contribute to N export and which may be sites of retention. In this study we investigated which watershed characteristics control N sourcing, biogeochemical processing of nitrate (NO 3 − ) during storms, and the amount of rainfall N that is retained within urban watersheds. We used triple isotopes of NO 3 − (δ 15 N, δ 18 O, and Δ 17 O) to identify sources and transformations of NO 3 − during storms from 10 nested arid urban watersheds that varied in stormwater infrastructure type and drainage area. Stormwater infrastructure and land coverretention basins, pipes, and grass cover dictated the sourcing of NO 3 − in runoff. Urban watersheds were strong sinks or sources of N to stormwater depending on runoff, which in turn was inversely related to retention basin density and positively related to imperviousness and precipitation. Our results suggest that watershed characteristics control the sources and transport of inorganic N in urban stormwater but that retention of inorganic N at the time scale of individual runoff events is controlled by hydrologic, rather than biogeochemical, mechanisms.

show abstract

“…The efficiency of NO 3 --N removal by denitrification in groundwater ranges from 0% to 100% and depends on aquifer hydrology and mineralogy (Hiscock et al, 2003), hydrologic flow paths, dissolved oxygen (DO), microbial community composition, energy sources and redox chemistry (Boyer et al, 2006). A particular challenge to the construction and validation of robust and predictive models of denitrification arises from the fact that controlling factors are highly variable in space and time, giving rise to "hot spots" and "hot moments" of activity that are difficult to predict (McClain et al, 2003). Nitrate is one of the common contaminants of groundwater in Ireland but significant variation in hydrogeological conditions and agricultural practices can create marked variation in NO 3 --N concentrations across the country.…”

Section: Introductionmentioning

confidence: 99%

Denitrification and indirect N2O emissions in groundwater: Hydrologic and biogeochemical influences

Jahangir

Johnston

Barrett

et al. 2013

Journal of Contaminant Hydrology

View full text Add to dashboard Cite

Identification of specific landscape areas with high and low groundwater denitrification potential is critical for improved management of agricultural nitrogen (N) export to ground and surface waters and indirect nitrous oxide (N 2 O) emissions. Denitrification products together with concurrent hydrogeochemical properties were analysed over two years at three depths at two low (L) and two high (H) permeability agricultural sites in Ireland. Mean N 2 O-N at H sites were significantly higher than L sites, and decreased with depth. Conversely, excess N 2 -N were significantly higher at L sites than H sites and did not vary with depth. Denitrifier functional genes were similar at all sites and depths. Data showed that highly favourable conditions prevailed for denitrification to occur -multiple electron donors, low redox potential (Eh <100 mV), low DO (<2 mg L -1 ), low permeability (k s <0.005 m d -1 ) and a shallow unsaturated zone (<2 m). Quantification of excess N 2 -N in groundwater helps to close N balances at the local, regional and global scales.

show abstract

Biogeochemical Hot Spots and Hot Moments at the Interface of Terrestrial and Aquatic Ecosystems

Cited by 1,939 publications

References 84 publications

Nitrous oxide fluxes from the littoral zone of a lake on the Qinghai-Tibetan Plateau

Nitrous oxide fluxes from the littoral zone of a lake on the Qinghai-Tibetan Plateau

Sources and Transport of Nitrogen in Arid Urban Watersheds

Denitrification and indirect N2O emissions in groundwater: Hydrologic and biogeochemical influences

Contact Info

Product

Resources

About