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

Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71–149) teragrams of carbon per year (TgC⋅y−1) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9–65) TgC⋅y−1in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36–110) TgC⋅y−1or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass–flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity.

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Precipitation and temperature drive continental-scale patterns in stream invertebrate production

Science Advances ◽

10.1126/sciadv.aav2348 ◽

2019 ◽

Vol 5 (4) ◽

pp. eaav2348 ◽

Cited By ~ 9

Author(s):

C. J. Patrick ◽

D. J. McGarvey ◽

J. H. Larson ◽

W. F. Cross ◽

D. C. Allen ◽

...

Keyword(s):

United States ◽

Secondary Production ◽

Structural Equation ◽

Terrestrial Ecosystems ◽

The United States ◽

Equation Modeling ◽

Modeling Framework ◽

Continental Scale ◽

Temperature And Precipitation ◽

Water Ecosystems

Secondary production, the growth of new heterotrophic biomass, is a key process in aquatic and terrestrial ecosystems that has been carefully measured in many flowing water ecosystems. We combine structural equation modeling with the first worldwide dataset on annual secondary production of stream invertebrate communities to reveal core pathways linking air temperature and precipitation to secondary production. In the United States, where the most extensive set of secondary production estimates and covariate data were available, we show that precipitation-mediated, low–stream flow events have a strong negative effect on secondary production. At larger scales (United States, Europe, Central America, and Pacific), we demonstrate the significance of a positive two-step pathway from air to water temperature to increasing secondary production. Our results provide insights into the potential effects of climate change on secondary production and demonstrate a modeling framework that can be applied across ecosystems.

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The carbon budget of terrestrial ecosystems at country-scale – a European case study

Biogeosciences Discussions ◽

10.5194/bgd-1-167-2004 ◽

2004 ◽

Vol 1 (1) ◽

pp. 167-193 ◽

Cited By ~ 10

Author(s):

I. A. Janssens ◽

A. Freibauer ◽

B. Schlamadinger ◽

R. Ceulemans ◽

P. Ciais ◽

...

Keyword(s):

Carbon Balance ◽

Management Practices ◽

A Priori ◽

Carbon Sources ◽

Terrestrial Ecosystems ◽

Carbon Fluxes ◽

Terrestrial Carbon ◽

Arable Soils ◽

Carbon Balances

Abstract. We summed estimates of the carbon balance of forests, grasslands, arable lands and peatlands to obtain country-specific estimates of the terrestrial carbon balance during the 1990s. Forests and grasslands were sinking carbon consistently, whereas arable soils were carbon sources in all European countries. Hence, countries dominated by arable lands tended to be losing carbon from their terrestrial ecosystems, whereas forest-dominated countries tended to be sinking carbon. In countries where peatlands are still being drained or extracted, net carbon balances were much lower than expected from land use. Net terrestrial carbon fluxes were typically small relative to fossil fuel-related carbon emissions. Only where fossil fluxes were small and net terrestrial fluxes were large did terrestrial carbon fluxes matter (ranged between uptake of 70% of fossil fluxes and increase of emissions with 25%). Nonetheless, at the European scale, the small net balance is composed of two very large but opposing fluxes: uptake by forests and grasslands and losses from arable lands and peatlands. Thus, relatively minor changes in either or both of these large component fluxes could strongly affect the net total, indicating that mitigation schemes should not be discarded a priori. In the absence of carbon-oriented land management, the current net carbon balance is bound to decline soon. Protecting it will require actions at three levels. Firstly, maintaining the current sink activity of forests. Secondly, altered agricultural management practices to turn arable soils into carbon sinks. Lastly, because carbon is lost more rapidly than sequestered, the current large reservoirs (wetlands and old forests) need extra protection.

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Analysis of Carbon Flux in Terrestrial Ecosystems from GOSAT Data in China

E3S Web of Conferences ◽

10.1051/e3sconf/20185303012 ◽

2018 ◽

Vol 53 ◽

pp. 03012

Author(s):

Lanlan Zhang ◽

Jinye Zhang ◽

Hui Lv ◽

Bangwu Sun

Keyword(s):

Carbon Storage ◽

Carbon Flux ◽

Storage Capacity ◽

Carbon Sink ◽

Carbon Sources ◽

Net Ecosystem Exchange ◽

Terrestrial Ecosystems ◽

Vegetation Coverage ◽

Temporal And Spatial Distribution ◽

Temporal And Spatial

In recent years, the evaluation of carbon sources and carbon sinks has become one of the major research topics. The temporal and spatial distribution of carbon flux and some factors that affect carbon flux were analyzed in this paper based on the Net Ecosystem Exchange (NEE) data, which were provided by Greenhouse Gases Observing Satellite (GOSAT) project and FLUXNET project. Then, we found that carbon flux had obvious seasonal variation. It was carbon sink in summer and carbon source in winter. The total amount of carbon flux in July or August was about -1.377 ~ -1.882 gcm-2day-1, and 0.64 gcm-2day-1 in November. The fluctuation of carbon flux in coastal area was stronger than that in inland. Forest areas had stronger carbon storage capacity than that in other vegetation areas, and the flux in forest areas had the largest change. The vegetation coverage was larger, and the carbon storage capacity was stronger.

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A regional high-resolution carbon flux inversion of North America for 2004

Biogeosciences ◽

10.5194/bg-7-1625-2010 ◽

2010 ◽

Vol 7 (5) ◽

pp. 1625-1644 ◽

Cited By ~ 89

Author(s):

A. E. Schuh ◽

A. S. Denning ◽

K. D. Corbin ◽

I. T. Baker ◽

M. Uliasz ◽

...

Keyword(s):

United States ◽

High Resolution ◽

North America ◽

Carbon Flux ◽

Ecosystem Respiration ◽

Carbon Fluxes ◽

The United States ◽

Mixing Ratio ◽

South Central ◽

Ratio Data

Abstract. Resolving the discrepancies between NEE estimates based upon (1) ground studies and (2) atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS) and an underlying biosphere (SiB3) model, both running on an identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well as many previous global inversions including the Transcom suite of inversions have utilized inversion regions formed by collapsing biome-similar grid cells into larger aggregated regions. An extreme example of this might be where corrections to NEE imposed on forested regions on the east coast of the United States might be the same as that imposed on forests on the west coast of the United States while, in reality, there likely exist subtle differences in the two areas, both natural and anthropogenic. Our current inversion framework utilizes a combination of previously employed inversion techniques while allowing carbon flux corrections to be biome independent. Temporally and spatially high-resolution results utilizing biome-independent corrections provide insight into carbon dynamics in North America. In particular, we analyze hourly CO2 mixing ratio data from a sparse network of eight towers in North America for 2004. A prior estimate of carbon fluxes due to Gross Primary Productivity (GPP) and Ecosystem Respiration (ER) is constructed from the SiB3 biosphere model on a 40 km grid. A combination of transport from the RAMS and the Parameterized Chemical Transport Model (PCTM) models is used to forge a connection between upwind biosphere fluxes and downwind observed CO2 mixing ratio data. A Kalman filter procedure is used to estimate weekly corrections to biosphere fluxes based upon observed CO2. RMSE-weighted annual NEE estimates, over an ensemble of potential inversion parameter sets, show a mean estimate 0.57 Pg/yr sink in North America. We perform the inversion with two independently derived boundary inflow conditions and calculate jackknife-based statistics to test the robustness of the model results. We then compare final results to estimates obtained from the CarbonTracker inversion system and at the Southern Great Plains flux site. Results are promising, showing the ability to correct carbon fluxes from the biosphere models over annual and seasonal time scales, as well as over the different GPP and ER components. Additionally, the correlation of an estimated sink of carbon in the South Central United States with regional anomalously high precipitation in an area of managed agricultural and forest lands provides interesting hypotheses for future work.

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Terrestrial Carbon Sinks for the United States Predicted from MODIS Satellite Data and Ecosystem Modeling

Earth Interactions ◽

10.1175/ei228.1 ◽

2007 ◽

Vol 11 (13) ◽

pp. 1-21 ◽

Cited By ~ 58

Author(s):

Christopher Potter ◽

Steven Klooster ◽

Alfredo Huete ◽

Vanessa Genovese

Keyword(s):

United States ◽

Pacific Northwest ◽

Vegetation Index ◽

Net Primary Production ◽

Regional Climate ◽

Terrestrial Ecosystems ◽

Carbon Fluxes ◽

The United States ◽

Carbon Sinks ◽

Modis Evi

Abstract A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of the conterminous United States over the period 2001–04. Predicted net ecosystem production (NEP) flux for atmospheric CO2 in the United States was estimated as annual net sink of about +0.2 Pg C in 2004. Regional climate patterns were reflected in the predicted annual NEP flux from the model, which showed extensive carbon sinks in ecosystems of the southern and eastern regions in 2003–04, and major carbon source fluxes from ecosystems in the Rocky Mountain and Pacific Northwest regions in 2003–04. As demonstrated through tower site comparisons, net primary production (NPP) modeled with monthly MODIS enhanced vegetation index (EVI) inputs closely resembles both the measured high- and low-season carbon fluxes. Modeling results suggest that the capacity of the NASA Carnegie Ames Stanford Approach (CASA) model to use 8-km resolution MODIS EVI data to predict peak growing season uptake rates of CO2 in irrigated croplands and moist temperate forests is strong.

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A regional high-resolution carbon flux inversion of North America for 2004

Biogeosciences Discussions ◽

10.5194/bgd-6-10195-2009 ◽

2009 ◽

Vol 6 (6) ◽

pp. 10195-10241 ◽

Cited By ~ 1

Author(s):

A. E. Schuh ◽

A. S. Denning ◽

K. D. Corbin ◽

I. T. Baker ◽

M. Uliasz ◽

...

Keyword(s):

United States ◽

High Resolution ◽

North America ◽

Carbon Flux ◽

Transport Model ◽

Ecosystem Respiration ◽

Carbon Fluxes ◽

The United States ◽

Mixing Ratio ◽

Ratio Data

Abstract. Resolving the discrepancies between NEE estimates based upon (1) ground studies and (2) atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS) and an underlying biosphere (SiB3) model, both running on an identical 40 km grid over most of North America. Previous papers have utilized inversion regions formed by collapsing biome-similar grid cells into large aggregated regions. The effect of this is that the NEE correction imposed on forested regions on the east coast of the United States might be the same as that imposed on forests on the west coast of the United States while, in reality, there likely exist subtle differences in the two areas, both natural and anthropogenic. Our current inversion framework utilizes a combination of previously employed inversion techniques while allowing carbon flux corrections to be biome independent. Temporally and spatially high-resolution results utilizing biome-independent corrections provide insight into carbon dynamics in North America. In particular, we analyze hourly CO2 mixing ratio data from a sparse network of eight towers in North America for 2004. A prior estimate of carbon fluxes due to gross primary productivity (GPP) and ecosystem respiration (ER) is constructed from the SiB3 biosphere model on a 40 km grid. A combination of transport from the RAMS and the parameterized chemical transport model (PCTM) models is used to forge a connection between upwind biosphere fluxes and downwind observed CO2 mixing ratio data. A Kalman filter procedure is used to estimate weekly corrections to biosphere fluxes based upon observed CO2. RMSE-weighted annual NEE estimates, over an ensemble of potential inversion parameter sets, show a mean estimate 0.57 Pg/yr sink in North America. We perform the inversion with two independently derived boundary inflow conditions and calculate jackknife-based statistics to test the robustness of the model results. We then compare final results to estimates obtained from the CarbonTracker inversion system and the Ameriflux network. Results are promising, showing the ability to correct carbon fluxes from the biosphere models over annual and seasonal time scales, as well as over the different GPP and ER components, and also providing interesting hypotheses for future work.

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