Characterization of denitrification activity in zones of groundwater exfiltration within a riparian wetland ecosystem

McCarty, Gregory W.; Mookherji, S.; Angier, J. T.

doi:10.1007/s00374-006-0151-0

Cited by 32 publications

(24 citation statements)

References 33 publications

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“…Thus, the application of molecular techniques would be useful to further characterize the abundance and composition of denitrifiers and investigate possible deposition-related effects. We compared our results to those determined with similar methods and found that the abundances of lake sediment denitrifiers were within the ranges reported for desert, riparian, and prairie ecosystems, but less than that for grazed and agricultural soils (Sotomayor and Rice 1996;Cannavo et al 2004;Johnson et al 2007;McCarty et al 2007). The MPN's may not be directly comparable because of differences in incubation conditions.…”

Section: Factors Influencing Denitrifier Abundancesupporting

confidence: 54%

Denitrification kinetics and denitrifier abundances in sediments of lakes receiving atmospheric nitrogen deposition (Colorado, USA)

McCrackin

Elser

2011

Biogeochemistry

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The transport and deposition of anthropogenic nitrogen (N) to downwind ecosystems is significant and can be a dominant source of new N to many watersheds. Bacterially mediated denitrification in lake sediments may ameliorate the effects of N loading by permanently removing such inputs. We measured denitrification in sediments collected from lakes in the Colorado Rocky Mountains (USA) receiving elevated (5-8 kg N ha -1 y -1 ) or low (\2 kg N ha -1 y -1 ) inputs of atmospheric N deposition. The nitrate (NO 3 -) concentration was significantly greater in high-deposition lakes (11.3 lmol l -1 ) compared to low-deposition lakes (3.3 lmol l -1 ). Background denitrification was positively related to NO 3 -concentrations and we estimate that the sampled lakes are capable of removing a significant portion of N inputs via sediment denitrification. We also conducted a dose-response experiment to determine whether chronic N loading has altered sediment denitrification capacity. Under Michaelis-Menten kinetics, the maximum denitrification rate and half-saturation NO 3 -concentration did not differ between deposition regions and were 765 lmol N m -2 h -1 and 293 lmol l -1 NO 3 -, respectively, for all lakes. We enumerated the abundances of nitrate-and nitrite-reducing bacteria and found no difference between high-and low-deposition lakes. The abundance of these bacteria was related to available light and bulk sediment resources. Our findings support a growing body of evidence that lakes play an important role in N removal and, furthermore, suggest that current levels of N deposition have not altered the abundance of denitrifying bacteria or saturated the capacity for sediment denitrification.

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Section: Factors Influencing Denitrifier Abundancesupporting

confidence: 54%

Denitrification kinetics and denitrifier abundances in sediments of lakes receiving atmospheric nitrogen deposition (Colorado, USA)

McCrackin

Elser

2011

Biogeochemistry

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“…However, the highest level of functional group richness, such as the treatment planted with 4 functional groups, significantly increased the BSR, implying that plant functional group level might have a threshold point in affecting the BSR in the CW substrate. Substrate induced respiration rate (SIR) is often used as an indicator of response of soil microorganisms to input of external organic matter into environments and is more reliable than basal respiration measurement in reflecting microbial activity (Jones and Ananyeva, 2001;Mccarty et al, 2007). Unlike the BSR, the SIR, despite of no significant difference across four planted treatments, was significantly higher in all planted treatments than in the unplanted treatments, indicating that the SIR strongly depended on the presence of plants in CW substrate.…”

Section: Discussionmentioning

confidence: 90%

Responses of microbial activity and community metabolic profiles to plant functional group diversity in a full-scale constructed wetland

Zhang¹,

Shi-sheng²,

Wang³

et al. 2011

Geoderma

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“…(laurel). Hollows have wetland plant assemblages dominated by Symplocarpus foetidus (skunk cabbage) which emerges in spring before canopy leaf out, has a very high foliar N content [McCarty et al, 2007], and quickly decays in midsummer. Logging in the area began in 1776 [Wolman, 1987] and large portions of this land were likely farmed in the eighteenth and [Bettez and Groffman, 2013].…”

Section: 1002/2015wr016937mentioning

confidence: 99%

Mechanisms driving the seasonality of catchment scale nitrate export: Evidence for riparian ecohydrologic controls

Duncan

Band

Groffman

et al. 2015

Water Resources Research

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Considerable variability in the seasonal patterns of stream water nitrate (NO 2 3 ) has been observed in forested watersheds throughout the world. While many forested headwater catchments exhibit winter and early spring peaks in NO 2 3 concentrations, several watersheds have peak concentrations during the summer months. Pond Branch, a headwater catchment in Maryland monitored for over 10 years, exhibits recurrent and broad summer peaks in both NO export from June to September is particularly surprising, given that these summer months typically have the year's lowest discharge. A key challenge is identifying the source(s) of NO 2 3 and the mechanism(s) by which it is transported to the watershed outlet during the summer. In this study, we assessed multiple hypotheses (not mutually exclusive) that could account for the seasonal trend including proximal controls of groundwater-surface water interactions, instream processes, and riparian groundwater-N cycling interactions, as well as two distal controls: geochemical weathering and senescence of riparian vegetation. A combination of long-term weekly and limited duration high-frequency sensor data reveals the importance of riparian ecohydrologic processes during base flow. In this watershed, patterns of seasonal stream water NO 2 3 concentrations and fluxes depend fundamentally on interactions between groundwater dynamics and nitrogen (N) cycling in the riparian zone. Groundwater tables control nitrification-denitrification dynamics as well as hydrologic transport. Our results suggest that in many watersheds, a more sophisticated exploration of NO 2 3 production and NO 2 3 transport mechanisms is required to identify critical points in the landscape and over time that disproportionately drive patterns of watershed NO 2 3 export.

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Characterization of denitrification activity in zones of groundwater exfiltration within a riparian wetland ecosystem

Cited by 32 publications

References 33 publications

Denitrification kinetics and denitrifier abundances in sediments of lakes receiving atmospheric nitrogen deposition (Colorado, USA)

Denitrification kinetics and denitrifier abundances in sediments of lakes receiving atmospheric nitrogen deposition (Colorado, USA)

Responses of microbial activity and community metabolic profiles to plant functional group diversity in a full-scale constructed wetland

Mechanisms driving the seasonality of catchment scale nitrate export: Evidence for riparian ecohydrologic controls

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