Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

Butman, David; Stackpoole, S. M.; Stets, Edward G.; McDonald, Cory P.; Clow, David W.; Striegl, Robert G.

doi:10.1073/pnas.1512651112

Cited by 209 publications

(222 citation statements)

References 72 publications

Supporting

Mentioning

199

Contrasting

Order By: Relevance

“…Although we are unable to produce a mass flux estimate for the entire pulse flow event, our calculated CO 2 and CH 4 fluxes are low relative to other U.S. rivers [ Butman et al ., ]. Across all measurements we show that the Colorado River delta emitted between 84 ± 12 to 347 ± 42 mmol m −2 d −1 CO 2 from the surface of the water to the atmosphere during the flooding event.…”

Section: Discussionmentioning

confidence: 99%

The experimental flow to the Colorado River delta: Effects on carbon mobilization in a dry watercourse

et al. 2017

Self Cite

View full text Add to dashboard Cite

Here we report on the effects of an experimental flood on the carbon cycling dynamics in the dry watercourse of the Colorado River in Mexico. We observed post‐flood differences in the degree of decay, age, and concentration of dissolved organic carbon (DOC), as well as dissolved CH4 and CO2 concentrations throughout the study site. Our results indicate that this flooded waterway was a limited source of CH4 and CO2 to the atmosphere during the event and that DOC age increased with time of flooding. Based on our findings, we suggest that the interplay between storage and mobilization of carbon and greenhouse gases in arid and semiarid regions is potentially sensitive to changing climate conditions, particularly hydrologic variability. Changes in the radiocarbon age of DOC throughout the flooding event suggest that organic matter (OM) that had been stored for long periods (e.g., millennial) was mobilized by the flooding event along with CO2. The OM residing in the dry riverbed that was mobilized into floodwaters had a signature reflective of degraded vascular plant OM and microbial biomass. Whether this microbial OM was living or dead, our findings support previous work in soils and natural waters showing that microbial OM can remain stable and stored in ecosystems for long time periods. As human appropriation of water resources continues to increase, the episodic drying and rewetting of once natural riverbeds and deltas may fundamentally alter the processing and storage of carbon in such systems.

show abstract

Section: Discussionmentioning

confidence: 99%

The experimental flow to the Colorado River delta: Effects on carbon mobilization in a dry watercourse

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…We did not observe such a correlation at smaller scale, which could be related to the rather narrow range of variability in NPP among the considered catchments. Nevertheless, the linear correlation observed by Butman et al (2015) indicates that a constant fraction of terrestrial NPP is exported by aquatic systems if averaged over larger spatial scales.…”

Section: Controlling Factors For Aquatic C-exportmentioning

confidence: 97%

Regional-scale lateral carbon transport and CO<sub>2</sub> evasion in temperate stream catchments

et al. 2017

View full text Add to dashboard Cite

Abstract. Inland waters play an important role in regional to global-scale carbon cycling by transporting, processing and emitting substantial amounts of carbon, which originate mainly from their catchments. In this study, we analyzed the relationship between terrestrial net primary production (NPP) and the rate at which carbon is exported from the catchments in a temperate stream network. The analysis included more than 200 catchment areas in southwest Germany, ranging in size from 0.8 to 889 km 2 for which CO 2 evasion from stream surfaces and downstream transport with stream discharge were estimated from water quality monitoring data, while NPP in the catchments was obtained from a global data set based on remote sensing. We found that on average 13.9 g C m −2 yr −1 (corresponding to 2.7 % of terrestrial NPP) are exported from the catchments by streams and rivers, in which both CO 2 evasion and downstream transport contributed about equally to this flux. The average carbon fluxes in the catchments of the study area resembled global and large-scale zonal mean values in many respects, including NPP, stream evasion and the carbon export per catchment area in the fluvial network. A review of existing studies on aquatic-terrestrial coupling in the carbon cycle suggests that the carbon export per catchment area varies in a relatively narrow range, despite a broad range of different spatial scales and hydrological characteristics of the study regions.

show abstract

“…, Butman et al. ) or, when examining downstream fluxes to the ocean, ignore OC storage along river corridors except in lakes and reservoirs (e.g., Regnier et al. ).…”

Section: Human Alterations Of Carbon Dynamics In River Corridorsmentioning

confidence: 99%

Carbon dynamics of river corridors and the effects of human alterations

Wohl

Hall

Lininger

et al. 2017

Ecological Monographs

101

View full text Add to dashboard Cite

Research in stream metabolism, gas exchange, and sediment dynamics indicates that rivers are an active component of the global carbon cycle and that river form and process can influence partitioning of terrestrially derived carbon among the atmosphere, geosphere, and ocean. Here we develop a conceptual model of carbon dynamics (inputs, outputs, and storage of organic carbon) within a river corridor, which includes the active channel and the riparian zone. The exchange of carbon from the channel to the riparian zone represents potential for storage of transported carbon not included in the “active pipe” model of organic carbon (OC) dynamics in freshwater systems. The active pipe model recognizes that river processes influence carbon dynamics, but focuses on CO2 emissions from the channel and eventual delivery to the ocean. We also review how human activities directly and indirectly alter carbon dynamics within river corridors. We propose that dams create the most significant alteration of carbon dynamics within a channel, but that alteration of riparian zones, including the reduction of lateral connectivity between the channel and riparian zone, constitutes the most substantial change of carbon dynamics in river corridors. We argue that the morphology and processes of a river corridor regulate the ability to store, transform, and transport OC, and that people are pervasive modifiers of river morphology and processes. The net effect of most human activities, with the notable exception of reservoir construction, appears to be that of reducing the ability of river corridors to store OC within biota and sediment, which effectively converts river corridors to OC sources rather than OC sinks. We conclude by summarizing knowledge gaps in OC dynamics and the implications of our findings for managing OC dynamics within river corridors.

show abstract

Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

Cited by 209 publications

References 72 publications

The experimental flow to the Colorado River delta: Effects on carbon mobilization in a dry watercourse

The experimental flow to the Colorado River delta: Effects on carbon mobilization in a dry watercourse

Regional-scale lateral carbon transport and CO<sub>2</sub> evasion in temperate stream catchments

Carbon dynamics of river corridors and the effects of human alterations

Contact Info

Product

Resources

About

Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

Cited by 209 publications

References 72 publications

The experimental flow to the Colorado River delta: Effects on carbon mobilization in a dry watercourse

The experimental flow to the Colorado River delta: Effects on carbon mobilization in a dry watercourse

Regional-scale lateral carbon transport and CO&lt;sub&gt;2&lt;/sub&gt; evasion in temperate stream catchments

Carbon dynamics of river corridors and the effects of human alterations

Contact Info

Product

Resources

About

Regional-scale lateral carbon transport and CO<sub>2</sub> evasion in temperate stream catchments