Jennifer Harden, PhD (Former Employee)
Science and Products
Filter Total Items: 134
Effects of permafrost aggradation on peat properties as determined from a pan-Arctic synthesis of plant macrofossils
Permafrost dynamics play an important role in high-latitude peatland carbon balance and are key to understanding the future response of soil carbon stocks. Permafrost aggradation can control the magnitude of the carbon feedback in peatlands through effects on peat properties. We compiled peatland plant macrofossil records for the northern permafrost zone (515 cores from 280 sites) and classified s
Authors
Claire C. Treat, Miriam C. Jones, P. Camill, A. Gallego-Sala, M. Garneau, Jennifer W. Harden, G. Hugelius, E.S. Klein, Ulla Kokfelt, P. Kuhry, Julie Loisel, J.H. Mathijssen, J.A. O'Donnell, P.O. Oksanen, T.M. Ronkainen, A. B. K. Sannel, J. J. Talbot, C.M. Tarnocal, M. Valiranta
Differential response of carbon fluxes to climate in three peatland ecosystems that vary in the presence and stability of permafrost
Changes in vegetation and soil properties following permafrost degradation and thermokarst development in peatlands may cause changes in net carbon storage. To better understand these dynamics, we established three sites in Alaska that vary in permafrost regime, including a black spruce peat plateau forest with stable permafrost, an internal collapse scar bog formed as a result of thermokarst, and
Authors
Eugenie S. Euskirchen, C.W. Edgar, M.R. Turetsky, Mark P. Waldrop, Jennifer W. Harden
A simplified, data-constrained approach to estimate the permafrost carbon–climate feedback
We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. W
Authors
C.D. Koven, E.A.G. Schuur, C. Schädel, T. J. Bohn, E. J. Burke, G. Chen, X. Chen, P. Ciais, G. Grosse, J. W. Harden, D.J. Hayes, G. Hugelius, Elchin E. Jafarov, G. Krinner, P. Kuhry, D.M. Lawrence, A. H. MacDougall, Sergey S. Marchenko, A. David McGuire, Susan M. Natali, D.J. Nicolsky, David Olefeldt, S. Peng, V.E. Romanovsky, Kevin M. Schaefer, J. Strauss, Claire C. Treat, M. Turetsky
Climate change and the permafrost carbon feedback
Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from thes
Authors
E.A.G. Schuur, A. David McGuire, C. Schädel, G. Grosse, J. W. Harden, D.J. Hayes, G. Hugelius, C.D. Koven, P. Kuhry, D.M. Lawrence, Susan M. Natali, David Olefeldt, V.E. Romanovsky, K. Schaefer, M.R. Turetsky, Claire C. Treat, J.E. Vonk
Long-term controls of soil organic carbon with depth and time: a case study from the Cowlitz River Chronosequence, WA USA
Over timescales of soil development (millennia), the capacity of soils to stabilize soil organic carbon (SOC) is linked to soil development through changes in soil mineralogy and other soil properties. In this study, an extensive dataset of soil profile chemistry and mineralogy is compiled from the Cowlitz River Chronosequence (CRC), WA USA. The CRC soils range in age from 0.25 to 1200 kyr, spanni
Authors
Corey R. Lawrence, Jennifer W. Harden, Xiaomei Xu, Marjorie S. Schulz, Susan E. Trumbore
Uranium isotopes and dissolved organic carbon in loess permafrost: Modeling the age of ancient ice
The residence time of ice in permafrost is an indicator of past climate history, and of the resilience and vulnerability of high-latitude ecosystems to global change. Development of geochemical indicators of ground-ice residence times in permafrost will advance understanding of the circumstances and evidence of permafrost formation, preservation, and thaw in response to climate warming and other d
Authors
Stephanie A. Ewing, James B. Paces, J.A. O'Donnell, M.T. Jorgenson, M.Z. Kanevskiy, George R. Aiken, Y. Shur, Jennifer W. Harden, Robert G. Striegl
Incorporating microbial dormancy dynamics into soil decomposition models to improve quantification of soil carbon dynamics of northern temperate forests
Soil carbon dynamics of terrestrial ecosystems play a significant role in the global carbon cycle. Microbial-based decomposition models have seen much growth recently for quantifying this role, yet dormancy as a common strategy used by microorganisms has not usually been represented and tested in these models against field observations. Here we developed an explicit microbial-enzyme decomposition
Authors
Yujie He, Jinyan Yang, Qianlai Zhuang, Jennifer W. Harden, A. David McGuire, Yaling Liu, Gangsheng Wang, Lianhong Gu
Effects of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence
Permafrost soils store over half of global soil carbon (C), and northern frozen peatlands store about 10% of global permafrost C. With thaw, inundation of high latitude lowland peatlands typically increases the surface-atmosphere flux of methane (CH4), a potent greenhouse gas. To examine the effects of lowland permafrost thaw over millennial timescales, we measured carbon dioxide (CO2) and CH4 exc
Authors
Carmel E. Johnston, Stephanie A. Ewing, Jennifer W. Harden, Ruth K. Varner, Kimberly P. Wickland, Joshua C. Koch, Christopher C. Fuller, Kristen L. Manies, M. Torre Jorgenson
The implications of microbial and substrate limitation for the fates of carbon in different organic soil horizon types of boreal forest ecosystems: a mechanistically based model analysis
The large amount of soil carbon in boreal forest ecosystems has the potential to influence the climate system if released in large quantities in response to warming. Thus, there is a need to better understand and represent the environmental sensitivity of soil carbon decomposition. Most soil carbon decomposition models rely on empirical relationships omitting key biogeochemical mechanisms and thei
Authors
Y. He, Q. Zhuang, Jennifer W. Harden, A. David McGuire, Z. Fan, Y. Liu, Kimberly P. Wickland
Modeling the influence of organic acids on soil weathering
Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the diss
Authors
Corey R. Lawrence, Jennifer W. Harden, Kate Maher
Soils, vegetation, and woody debris data from the 2001 Survey Line fire and a comparable unburned site, Tanana Flats region, Alaska
This report describes the collection and processing methodologies for samples obtained at two sites within Interior Alaska: (1) a location within the 2001 Survey Line burn, and (2) an unburned location, selected as a control. In 2002 and 2004 U.S. Geological Survey investigators measured soil properties including, but not limited to, bulk density, volumetric water content, carbon content, and nitr
Authors
Kristen L. Manies, Jennifer W. Harden, Teresa N. Holingsworth
Controls on methane released through ebullition in peatlands affected by permafrost degradation
Permafrost thaw in peat plateaus leads to the flooding of surface soils and the formation of collapse scar bogs, which have the potential to be large emitters of methane (CH4) from surface peat as well as deeper, previously frozen, permafrost carbon (C). We used a network of bubble traps, permanently installed 20 cm and 60 cm beneath the moss surface, to examine controls on ebullition from three c
Authors
Sara J. Klapstein, Merritt R. Turetsky, A. David McGuire, Jennifer W. Harden, C.I. Czimczik, Xiaomei Xu, J. P. Chanton, James Michael Waddington
Science and Products
Filter Total Items: 134
Effects of permafrost aggradation on peat properties as determined from a pan-Arctic synthesis of plant macrofossils
Permafrost dynamics play an important role in high-latitude peatland carbon balance and are key to understanding the future response of soil carbon stocks. Permafrost aggradation can control the magnitude of the carbon feedback in peatlands through effects on peat properties. We compiled peatland plant macrofossil records for the northern permafrost zone (515 cores from 280 sites) and classified s
Authors
Claire C. Treat, Miriam C. Jones, P. Camill, A. Gallego-Sala, M. Garneau, Jennifer W. Harden, G. Hugelius, E.S. Klein, Ulla Kokfelt, P. Kuhry, Julie Loisel, J.H. Mathijssen, J.A. O'Donnell, P.O. Oksanen, T.M. Ronkainen, A. B. K. Sannel, J. J. Talbot, C.M. Tarnocal, M. Valiranta
Differential response of carbon fluxes to climate in three peatland ecosystems that vary in the presence and stability of permafrost
Changes in vegetation and soil properties following permafrost degradation and thermokarst development in peatlands may cause changes in net carbon storage. To better understand these dynamics, we established three sites in Alaska that vary in permafrost regime, including a black spruce peat plateau forest with stable permafrost, an internal collapse scar bog formed as a result of thermokarst, and
Authors
Eugenie S. Euskirchen, C.W. Edgar, M.R. Turetsky, Mark P. Waldrop, Jennifer W. Harden
A simplified, data-constrained approach to estimate the permafrost carbon–climate feedback
We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. W
Authors
C.D. Koven, E.A.G. Schuur, C. Schädel, T. J. Bohn, E. J. Burke, G. Chen, X. Chen, P. Ciais, G. Grosse, J. W. Harden, D.J. Hayes, G. Hugelius, Elchin E. Jafarov, G. Krinner, P. Kuhry, D.M. Lawrence, A. H. MacDougall, Sergey S. Marchenko, A. David McGuire, Susan M. Natali, D.J. Nicolsky, David Olefeldt, S. Peng, V.E. Romanovsky, Kevin M. Schaefer, J. Strauss, Claire C. Treat, M. Turetsky
Climate change and the permafrost carbon feedback
Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from thes
Authors
E.A.G. Schuur, A. David McGuire, C. Schädel, G. Grosse, J. W. Harden, D.J. Hayes, G. Hugelius, C.D. Koven, P. Kuhry, D.M. Lawrence, Susan M. Natali, David Olefeldt, V.E. Romanovsky, K. Schaefer, M.R. Turetsky, Claire C. Treat, J.E. Vonk
Long-term controls of soil organic carbon with depth and time: a case study from the Cowlitz River Chronosequence, WA USA
Over timescales of soil development (millennia), the capacity of soils to stabilize soil organic carbon (SOC) is linked to soil development through changes in soil mineralogy and other soil properties. In this study, an extensive dataset of soil profile chemistry and mineralogy is compiled from the Cowlitz River Chronosequence (CRC), WA USA. The CRC soils range in age from 0.25 to 1200 kyr, spanni
Authors
Corey R. Lawrence, Jennifer W. Harden, Xiaomei Xu, Marjorie S. Schulz, Susan E. Trumbore
Uranium isotopes and dissolved organic carbon in loess permafrost: Modeling the age of ancient ice
The residence time of ice in permafrost is an indicator of past climate history, and of the resilience and vulnerability of high-latitude ecosystems to global change. Development of geochemical indicators of ground-ice residence times in permafrost will advance understanding of the circumstances and evidence of permafrost formation, preservation, and thaw in response to climate warming and other d
Authors
Stephanie A. Ewing, James B. Paces, J.A. O'Donnell, M.T. Jorgenson, M.Z. Kanevskiy, George R. Aiken, Y. Shur, Jennifer W. Harden, Robert G. Striegl
Incorporating microbial dormancy dynamics into soil decomposition models to improve quantification of soil carbon dynamics of northern temperate forests
Soil carbon dynamics of terrestrial ecosystems play a significant role in the global carbon cycle. Microbial-based decomposition models have seen much growth recently for quantifying this role, yet dormancy as a common strategy used by microorganisms has not usually been represented and tested in these models against field observations. Here we developed an explicit microbial-enzyme decomposition
Authors
Yujie He, Jinyan Yang, Qianlai Zhuang, Jennifer W. Harden, A. David McGuire, Yaling Liu, Gangsheng Wang, Lianhong Gu
Effects of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence
Permafrost soils store over half of global soil carbon (C), and northern frozen peatlands store about 10% of global permafrost C. With thaw, inundation of high latitude lowland peatlands typically increases the surface-atmosphere flux of methane (CH4), a potent greenhouse gas. To examine the effects of lowland permafrost thaw over millennial timescales, we measured carbon dioxide (CO2) and CH4 exc
Authors
Carmel E. Johnston, Stephanie A. Ewing, Jennifer W. Harden, Ruth K. Varner, Kimberly P. Wickland, Joshua C. Koch, Christopher C. Fuller, Kristen L. Manies, M. Torre Jorgenson
The implications of microbial and substrate limitation for the fates of carbon in different organic soil horizon types of boreal forest ecosystems: a mechanistically based model analysis
The large amount of soil carbon in boreal forest ecosystems has the potential to influence the climate system if released in large quantities in response to warming. Thus, there is a need to better understand and represent the environmental sensitivity of soil carbon decomposition. Most soil carbon decomposition models rely on empirical relationships omitting key biogeochemical mechanisms and thei
Authors
Y. He, Q. Zhuang, Jennifer W. Harden, A. David McGuire, Z. Fan, Y. Liu, Kimberly P. Wickland
Modeling the influence of organic acids on soil weathering
Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the diss
Authors
Corey R. Lawrence, Jennifer W. Harden, Kate Maher
Soils, vegetation, and woody debris data from the 2001 Survey Line fire and a comparable unburned site, Tanana Flats region, Alaska
This report describes the collection and processing methodologies for samples obtained at two sites within Interior Alaska: (1) a location within the 2001 Survey Line burn, and (2) an unburned location, selected as a control. In 2002 and 2004 U.S. Geological Survey investigators measured soil properties including, but not limited to, bulk density, volumetric water content, carbon content, and nitr
Authors
Kristen L. Manies, Jennifer W. Harden, Teresa N. Holingsworth
Controls on methane released through ebullition in peatlands affected by permafrost degradation
Permafrost thaw in peat plateaus leads to the flooding of surface soils and the formation of collapse scar bogs, which have the potential to be large emitters of methane (CH4) from surface peat as well as deeper, previously frozen, permafrost carbon (C). We used a network of bubble traps, permanently installed 20 cm and 60 cm beneath the moss surface, to examine controls on ebullition from three c
Authors
Sara J. Klapstein, Merritt R. Turetsky, A. David McGuire, Jennifer W. Harden, C.I. Czimczik, Xiaomei Xu, J. P. Chanton, James Michael Waddington
*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