Jennifer Harden, PhD (Former Employee)
Science and Products
Filter Total Items: 144
Short-term response of methane fluxes and methanogen activity to water table and soil warming manipulations in an Alaskan peatland Short-term response of methane fluxes and methanogen activity to water table and soil warming manipulations in an Alaskan peatland
Growing season CH4 fluxes were monitored over a two year period following the start of ecosystem-scale manipulations of water table position and surface soil temperatures in a moderate rich fen in interior Alaska. The largest CH4 fluxes occurred in plots that received both flooding (raised water table position) and soil warming, while the lowest fluxes occurred in unwarmed plots in the...
Authors
M. R. Turetsky, C. C. Treat, M. P. Waldrop, J. M. Waddington, Jennifer W. Harden, A. David McGuire
Soil erosion: data say C sink Soil erosion: data say C sink
No abstract available.
Authors
J.W. Harden, A.A. Berhe, M.S. Torn, J.J. Harte, Shu-Guang Liu, Robert F. Stallard
Carbon sequestration to mitigate climate change Carbon sequestration to mitigate climate change
Human activities, especially the burning of fossil fuels such as coal, oil, and gas, have caused a substantial increase in the concentration of carbon dioxide (CO2) in the atmosphere. This increase in atmospheric CO2 - from about 280 to more than 380 parts per million (ppm) over the last 250 years - is causing measurable global warming. Potential adverse impacts include sea-level rise...
Authors
Eric Sundquist, Robert Burruss, Stephen Faulkner, Robert Gleason, Jennifer Harden, Yousif Kharaka, Larry Tieszen, Mark Waldrop
Wetland succession in a permafrost collapse: Interactions between fire and thermokarst Wetland succession in a permafrost collapse: Interactions between fire and thermokarst
To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate ???600 years of vegetation succession with...
Authors
I. H. Myers-Smith, J.W. Harden, M. Wilmking, C. C. Fuller, A. D. McGuire, F. S. Chapin
Recovery of aboveground plant biomass and productivity after fire in mesic and dry black spruce forests of interior Alaska Recovery of aboveground plant biomass and productivity after fire in mesic and dry black spruce forests of interior Alaska
Plant biomass accumulation and productivity are important determinants of ecosystem carbon (C) balance during post-fire succession. In boreal black spruce (Picea mariana) forests near Delta Junction, Alaska, we quantified aboveground plant biomass and net primary productivity (ANPP) for 4 years after a 1999 wildfire in a well-drained (dry) site, and also across a dry and a moderately...
Authors
M.C. Mack, K.K. Treseder, K.L. Manies, J.W. Harden, E.A.G. Schuur, J.G. Vogel, J. T. Randerson, F. S. Chapin
Interactive effects of wildfire and permafrost on microbial communities and soil processes in an Alaskan black spruce forest Interactive effects of wildfire and permafrost on microbial communities and soil processes in an Alaskan black spruce forest
Boreal forests contain significant quantities of soil carbon that may be oxidized to CO2 given future increases in climate warming and wildfire behavior. At the ecosystem scale, decomposition and heterotrophic respiration are strongly controlled by temperature and moisture, but we questioned whether changes in microbial biomass, activity, or community structure induced by fire might also...
Authors
M. P. Waldrop, J.W. Harden
The impact of agricultural soil erosion on the global carbon cycle The impact of agricultural soil erosion on the global carbon cycle
Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year–1 to a sink of the same magnitude. By using caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink of atmospheric carbon equivalent to approximately 26% of the carbon...
Authors
Kristof Van Oost, T.A. Quine, G. Govers, S. De Gryze, J. Six, J.W. Harden, J.C. Ritchie, G.W. McCarty, G. Heckrath, C. Kosmas, J.V. Giraldez, J.R. Marques Da Silva, R. Merckx
Influence of disturbance on carbon exchange in a permafrost collapse and adjacent burned forest Influence of disturbance on carbon exchange in a permafrost collapse and adjacent burned forest
We measured CO2 and CH4 exchange from the center of a Sphagnum‐dominated permafrost collapse, through an aquatic moat, and into a recently burned black spruce forest on the Tanana River floodplain in interior Alaska. In the anomalously dry growing season of 2004, both the collapse and the surrounding burned area were net sinks for CO2, with a mean daytime net ecosystem exchange of −1.4...
Authors
I. H. Myers-Smith, A. D. McGuire, J.W. Harden, F. S. Chapin
Soil Data from a Moderately Well and Somewhat Poorly Drained Fire Chronosequence near Thompson, Manitoba, Canada Soil Data from a Moderately Well and Somewhat Poorly Drained Fire Chronosequence near Thompson, Manitoba, Canada
The U.S. Geological Survey project Fate of Carbon in Alaskan Landscapes (FOCAL) is studying the effect of fire and soil drainage on soil carbon storage in the boreal forest. As such this group was invited to be a part of a NSF-funded project (Fire, Ecosystem and Succession - Experiment Boreal or FIRES-ExB) to study the carbon balance of sites that varied in age (time since fire) and soil...
Authors
K.L. Manies, J.W. Harden, Hugo Veldhuis, Sue Trumbore
Reconciling carbon-cycle concepts, terminology, and methods Reconciling carbon-cycle concepts, terminology, and methods
Recent projections of climatic change have focused a great deal of scientific and public attention on patterns of carbon (C) cycling as well as its controls, particularly the factors that determine whether an ecosystem is a net source or sink of atmospheric carbon dioxide (CO2). Net ecosystem production (NEP), a central concept in C-cycling research, has been used by scientists to...
Authors
F. S. Chapin, G. M. Woodwell, J. T. Randerson, E. B. Rastetter, G. Lovett, D. D. Baldocchi, D. A. Clark, M. E. Harmon, D. S. Schimel, R. Valentini, C. Wirth, J. D. Aber, J. J. Cole, M. L. Goulden, Jennifer W. Harden, M. Heimann, R. W. Howarth, P. A. Matson, A. D. McGuire, J. M. Melillo, H. A. Mooney, J. C. Neff, R. A. Houghton, M. L. Pace, M. G. Ryan, S. W. Running, O. E. Sala, W. H. Schlesinger, E. #NAME? Schulze
The impact of boreal forest fire on climate warming The impact of boreal forest fire on climate warming
We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 ?? 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over...
Authors
J. T. Randerson, H. Liu, M.G. Flanner, S.D. Chambers, Y. Jin, P.G. Hess, G. Pfister, M.C. Mack, K.K. Treseder, L.R. Welp, F.S. Chapin, J.W. Harden, M. L. Goulden, E. Lyons, J. C. Neff, E.A.G. Schuur, C.S. Zender
Effects of wildfire and permafrost on soil organic matter and soil climate in interior Alaska Effects of wildfire and permafrost on soil organic matter and soil climate in interior Alaska
The influence of discontinuous permafrost on ground-fuel storage, combustion losses, and postfire soil climates was examined after a wildfire near Delta Junction, AK in July 1999. At this site, we sampled soils from a four-way site comparison of burning (burned and unburned) and permafrost (permafrost and nonpermafrost). Soil organic layers (which comprise ground-fuel storage) were...
Authors
J.W. Harden, K.L. Manies, M.R. Turetsky, J. C. Neff
Science and Products
Filter Total Items: 144
Short-term response of methane fluxes and methanogen activity to water table and soil warming manipulations in an Alaskan peatland Short-term response of methane fluxes and methanogen activity to water table and soil warming manipulations in an Alaskan peatland
Growing season CH4 fluxes were monitored over a two year period following the start of ecosystem-scale manipulations of water table position and surface soil temperatures in a moderate rich fen in interior Alaska. The largest CH4 fluxes occurred in plots that received both flooding (raised water table position) and soil warming, while the lowest fluxes occurred in unwarmed plots in the...
Authors
M. R. Turetsky, C. C. Treat, M. P. Waldrop, J. M. Waddington, Jennifer W. Harden, A. David McGuire
Soil erosion: data say C sink Soil erosion: data say C sink
No abstract available.
Authors
J.W. Harden, A.A. Berhe, M.S. Torn, J.J. Harte, Shu-Guang Liu, Robert F. Stallard
Carbon sequestration to mitigate climate change Carbon sequestration to mitigate climate change
Human activities, especially the burning of fossil fuels such as coal, oil, and gas, have caused a substantial increase in the concentration of carbon dioxide (CO2) in the atmosphere. This increase in atmospheric CO2 - from about 280 to more than 380 parts per million (ppm) over the last 250 years - is causing measurable global warming. Potential adverse impacts include sea-level rise...
Authors
Eric Sundquist, Robert Burruss, Stephen Faulkner, Robert Gleason, Jennifer Harden, Yousif Kharaka, Larry Tieszen, Mark Waldrop
Wetland succession in a permafrost collapse: Interactions between fire and thermokarst Wetland succession in a permafrost collapse: Interactions between fire and thermokarst
To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate ???600 years of vegetation succession with...
Authors
I. H. Myers-Smith, J.W. Harden, M. Wilmking, C. C. Fuller, A. D. McGuire, F. S. Chapin
Recovery of aboveground plant biomass and productivity after fire in mesic and dry black spruce forests of interior Alaska Recovery of aboveground plant biomass and productivity after fire in mesic and dry black spruce forests of interior Alaska
Plant biomass accumulation and productivity are important determinants of ecosystem carbon (C) balance during post-fire succession. In boreal black spruce (Picea mariana) forests near Delta Junction, Alaska, we quantified aboveground plant biomass and net primary productivity (ANPP) for 4 years after a 1999 wildfire in a well-drained (dry) site, and also across a dry and a moderately...
Authors
M.C. Mack, K.K. Treseder, K.L. Manies, J.W. Harden, E.A.G. Schuur, J.G. Vogel, J. T. Randerson, F. S. Chapin
Interactive effects of wildfire and permafrost on microbial communities and soil processes in an Alaskan black spruce forest Interactive effects of wildfire and permafrost on microbial communities and soil processes in an Alaskan black spruce forest
Boreal forests contain significant quantities of soil carbon that may be oxidized to CO2 given future increases in climate warming and wildfire behavior. At the ecosystem scale, decomposition and heterotrophic respiration are strongly controlled by temperature and moisture, but we questioned whether changes in microbial biomass, activity, or community structure induced by fire might also...
Authors
M. P. Waldrop, J.W. Harden
The impact of agricultural soil erosion on the global carbon cycle The impact of agricultural soil erosion on the global carbon cycle
Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year–1 to a sink of the same magnitude. By using caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink of atmospheric carbon equivalent to approximately 26% of the carbon...
Authors
Kristof Van Oost, T.A. Quine, G. Govers, S. De Gryze, J. Six, J.W. Harden, J.C. Ritchie, G.W. McCarty, G. Heckrath, C. Kosmas, J.V. Giraldez, J.R. Marques Da Silva, R. Merckx
Influence of disturbance on carbon exchange in a permafrost collapse and adjacent burned forest Influence of disturbance on carbon exchange in a permafrost collapse and adjacent burned forest
We measured CO2 and CH4 exchange from the center of a Sphagnum‐dominated permafrost collapse, through an aquatic moat, and into a recently burned black spruce forest on the Tanana River floodplain in interior Alaska. In the anomalously dry growing season of 2004, both the collapse and the surrounding burned area were net sinks for CO2, with a mean daytime net ecosystem exchange of −1.4...
Authors
I. H. Myers-Smith, A. D. McGuire, J.W. Harden, F. S. Chapin
Soil Data from a Moderately Well and Somewhat Poorly Drained Fire Chronosequence near Thompson, Manitoba, Canada Soil Data from a Moderately Well and Somewhat Poorly Drained Fire Chronosequence near Thompson, Manitoba, Canada
The U.S. Geological Survey project Fate of Carbon in Alaskan Landscapes (FOCAL) is studying the effect of fire and soil drainage on soil carbon storage in the boreal forest. As such this group was invited to be a part of a NSF-funded project (Fire, Ecosystem and Succession - Experiment Boreal or FIRES-ExB) to study the carbon balance of sites that varied in age (time since fire) and soil...
Authors
K.L. Manies, J.W. Harden, Hugo Veldhuis, Sue Trumbore
Reconciling carbon-cycle concepts, terminology, and methods Reconciling carbon-cycle concepts, terminology, and methods
Recent projections of climatic change have focused a great deal of scientific and public attention on patterns of carbon (C) cycling as well as its controls, particularly the factors that determine whether an ecosystem is a net source or sink of atmospheric carbon dioxide (CO2). Net ecosystem production (NEP), a central concept in C-cycling research, has been used by scientists to...
Authors
F. S. Chapin, G. M. Woodwell, J. T. Randerson, E. B. Rastetter, G. Lovett, D. D. Baldocchi, D. A. Clark, M. E. Harmon, D. S. Schimel, R. Valentini, C. Wirth, J. D. Aber, J. J. Cole, M. L. Goulden, Jennifer W. Harden, M. Heimann, R. W. Howarth, P. A. Matson, A. D. McGuire, J. M. Melillo, H. A. Mooney, J. C. Neff, R. A. Houghton, M. L. Pace, M. G. Ryan, S. W. Running, O. E. Sala, W. H. Schlesinger, E. #NAME? Schulze
The impact of boreal forest fire on climate warming The impact of boreal forest fire on climate warming
We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 ?? 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over...
Authors
J. T. Randerson, H. Liu, M.G. Flanner, S.D. Chambers, Y. Jin, P.G. Hess, G. Pfister, M.C. Mack, K.K. Treseder, L.R. Welp, F.S. Chapin, J.W. Harden, M. L. Goulden, E. Lyons, J. C. Neff, E.A.G. Schuur, C.S. Zender
Effects of wildfire and permafrost on soil organic matter and soil climate in interior Alaska Effects of wildfire and permafrost on soil organic matter and soil climate in interior Alaska
The influence of discontinuous permafrost on ground-fuel storage, combustion losses, and postfire soil climates was examined after a wildfire near Delta Junction, AK in July 1999. At this site, we sampled soils from a four-way site comparison of burning (burned and unburned) and permafrost (permafrost and nonpermafrost). Soil organic layers (which comprise ground-fuel storage) were...
Authors
J.W. Harden, K.L. Manies, M.R. Turetsky, J. C. Neff
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government