Groundwater flux and open-channel estimation of stream metabolism: response to Hall and Tank

McCutchan, James H.; Lewis, William M.

doi:10.4319/lom.2006.4.213

Cited by 12 publications

(25 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1: diel mass balance of O 2 -This approach, which does not include d 18 O 2 , has been used in numerous stream studies and is described in detail elsewhere (McCutchan et al 2002;Hall and Tank 2005;McCutchan and Lewis 2006). This approach for estimating P, R, and P : R requires diel O 2 records and an estimate of O 2 gas transfer and can be approximated by (McCutchan et al 2003;Hall and Tank 2005) …”

Section: Discussionmentioning

confidence: 99%

The oxygen‐18 isotope approach for measuring aquatic metabolism in high productivity waters

Tobias

Böhlke

Harvey

2007

Limnology & Oceanography

View full text Add to dashboard Cite

We examined the utility of d 18 O 2 measurements in estimating gross primary production (P), community respiration (R), and net metabolism (P : R) through diel cycles in a productive agricultural stream located in the midwestern U.S.A. Large diel swings in O 2 (6200 mmol L 21 ) were accompanied by large diel variation in d 18 O 2 (610%). Simultaneous gas transfer measurements and laboratory-derived isotopic fractionation factors for O 2 during respiration (a r ) were used in conjunction with the diel monitoring of O 2 and d 18 O 2 to calculate P, R, and P : R using three independent isotope-based methods. These estimates were compared to each other and against the traditional ''open-channel diel O 2 -change'' technique that lacked d 18 O 2 . A principal advantage of the d 18 O 2 measurements was quantification of diel variation in R, which increased by up to 30% during the day, and the diel pattern in R was variable and not necessarily predictable from assumed temperature effects on R. The P, R, and P : R estimates calculated using the isotope-based approaches showed high sensitivity to the assumed system fractionation factor (a r ). The optimum modeled a r values (0.986-0.989) were roughly consistent with the laboratory-derived values, but larger (i.e., less fractionation) than a r values typically reported for enzyme-limited respiration in open water environments. Because of large diel variation in O 2 , P : R could not be estimated by directly applying the typical steady-state solution to the O 2 and 18 O-O 2 mass balance equations in the absence of gas transfer data. Instead, our results indicate that a modified steady-state solution (the daily mean value approach) could be used with time-averaged O 2 and d 18 O 2 measurements to calculate P : R independent of gas transfer. This approach was applicable under specifically defined, net heterotrophic conditions. The diel cycle of increasing daytime R and decreasing nighttime R was only partially explained by temperature variation, but could be consistent with the diel production/consumption of labile dissolved organic carbon from photosynthesis.Gross primary production (P) and community respiration (R) are central regulators of biogeochemical turnover in aquatic environments on local to regional scales (del Giorgio et al. 1997;Duarte and Agusti 1998;Cole et al. 2000). The balance between P and R (i.e., net metabolism) provides an indicator of nutrient enrichment, trophic status, allochthonous organic carbon utilization, and overall water quality (del Giorgio and Peters 1994;Hanson et al. 2003). Accurate estimates of P and R are needed to assess carbon, oxygen, and nutrient processing on watershed scales (Mulholland et al. 1997;Sabater et al. 2000;Hall and Tank 2003).In situ estimates of P and R traditionally have relied upon O 2 budgets that balanced sources and sinks of O 2 (e.g., photosynthesis and respiration) with O 2 exchange (invasion or evasion) between water and the atmosphere. For experimental purposes in the current study, as in most previous ...

show abstract

Section: Discussionmentioning

confidence: 99%

The oxygen‐18 isotope approach for measuring aquatic metabolism in high productivity waters

Tobias

Böhlke

Harvey

2007

Limnology & Oceanography

View full text Add to dashboard Cite

show abstract

“…Essentially, this is a mass balance of oxygen of a thin parcel of water moving downstream along the river channel (see McCutchan & Lewis, 2006). Essentially, this is a mass balance of oxygen of a thin parcel of water moving downstream along the river channel (see McCutchan & Lewis, 2006).…”

Section: Stream Metabolism Method: a Reappraisalmentioning

confidence: 99%

Temperature and the metabolic balance of streams

et al. 2011

View full text Add to dashboard Cite

Summary 1. It is becoming increasingly clear that fresh waters play a major role in the global C cycle. Stream ecosystem respiration (ER) and gross primary productivity (GPP) exert a significant control on organic carbon fluxes in fluvial networks. However, little is known about how climate change will influence these fluxes. 2. Here, we used a ‘natural experiment’ to demonstrate the role of temperature and nutrient cycling in whole‐system metabolism (ER, GPP and net ecosystem production – NEP), in naturally heated geothermal (5–25 °C) Icelandic streams. 3. We calculated ER and GPP with a new, more accurate method, which enabled us to take into account the additional uncertainties owing to stream spatial heterogeneity in oxygen concentrations within a reach. ER ranged 1–25 g C m−2 day−1 and GPP 1–10 g C m−2 day−1. The median uncertainties (based on 1 SD) in ER and GPP were 50% and 20%, respectively. 4. Despite extremely low water nutrient concentrations, high metabolic rates in the warm streams were supported by fast cycling rates of nutrients, as revealed from inorganic nutrient (N, P) addition experiments. 5. ER exceeded GPP in all streams (with average GPP/ER = 0.6) and was more strongly related to temperature than GPP, resulting in elevated negative NEP with warming. We show that, as a first approximation based on summer investigations, global stream carbon emission to the atmosphere would nearly double from 0.12 Pg C year−1 at 13 °C to 0.21 (0.15–0.33) Pg C year−1 with a 5 °C warming. 6. Compared to previous studies from natural systems (including terrestrial ecosystems), the temperature dependence of stream metabolism was not confounded by latitude or altitude, seasonality, light and nutrient availability, water chemistry, space availability (water transient storage), and water availability. 7. Consequently, stream nutrient processing is likely to increase with warming, protecting downstream ecosystems (rivers, estuaries, coastal marine systems) during the summer low flows from nutrient enrichment, but at the cost of increased CO2 flux back to the atmosphere.

show abstract

“…The term @ C/@ t| x = fixed is evaluated from the DO measurements at a fixed downstream location in the stream. Hornberger and Kelly, 1975;McCutchan and Lewis, 2006) which allows this method to account for the total rate of change of DO along x-distance of the stream defined as dC dt ¼ @C @t þ U @C @x . The method is also based on Equation (2), the same starting point as the one-station method; however, the change in DO concentration is referenced with respect to a moving reference frame (e.g.…”

Section: Dissolved Oxygen Balancementioning

confidence: 99%

“…A diurnal change in DO concentration is determined by photosynthetic primary production, respiration, and gas exchange with the atmosphere (Bott, 2006). Open-system single-station and two-station methods have been used to estimate the whole-ecosystem rate of GPP and R in flowing waters (Odum, 1956;Hall, 1972;Erdman, 1979;Bott, 2006;McCutchan and Lewis, 2006;Reichert et al, 2009). Open-system single-station and two-station methods have been used to estimate the whole-ecosystem rate of GPP and R in flowing waters (Odum, 1956;Hall, 1972;Erdman, 1979;Bott, 2006;McCutchan and Lewis, 2006;Reichert et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Estimating and scaling stream ecosystem metabolism along channels with heterogeneous substrate

et al. 2013

View full text Add to dashboard Cite

Measured diurnal curves of dissolved oxygen (DO) concentration have been used to estimate the gross primary production (GPP), ecosystem respiration (R), and net ecosystem production (NP) of aquatic communities. Open-system one-station and twostation methods have been employed to estimate the rate of NP, R, and GPP. We conducted field measurements in Minnehaha Creek, MN (44 o 56'N, 93 o 28'W), to quantify the spatial and temporal variabilities of DO concentrations and, consequently, evaluated the estimates of NP. Dimensionless analysis of DO mass balance revealed the dominance of local photosynthesis over respiration, advection, re-aeration, and dispersion along the studied reach. Two alternative estimation methods of stream metabolism provided similar estimates of NP with 0.65 > k a T a > 0.17 within the studied reach where k a is the re-aeration rate and T a is the water parcel average travel time. The spatial variability of DO change along the creek revealed an average length scale of 10 m over which DO exhibited significant autocorrelation. The autotrophic-heterotrophic balance, quantified by GPP to R ratio, scaled with local stream geomorphic and hydraulic conditions from diverse geographic areas, providing useful predictive relationships expressed in terms of easily measurable abiotic parameters.

show abstract

Groundwater flux and open-channel estimation of stream metabolism: response to Hall and Tank

Abstract: Rates of metabolism for a stream can be estimated from open-channel measurements of dissolved oxygen at 1 or 2 stations, provided that reaeration flux and groundwater flux to the channel are quantified, and the underlying assumptions of the mass-balance method are satisfied. Hall and Tank

Cited by 12 publications

References 5 publications

The oxygen‐18 isotope approach for measuring aquatic metabolism in high productivity waters

The oxygen‐18 isotope approach for measuring aquatic metabolism in high productivity waters

Temperature and the metabolic balance of streams

Estimating and scaling stream ecosystem metabolism along channels with heterogeneous substrate

Contact Info

Product

Resources

About