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Carlos Ernesto Goncalves Reynaud Schaefer - One of the best experts on this subject based on the ideXlab platform.
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active layer thermal regime at different vegetation covers at lions rump king george island maritime antarctica
Geomorphology, 2014Co-Authors: Ivan C C Almeida, Carlos Ernesto Goncalves Reynaud Schaefer, Thiago Torres Costa Pereira, Raphael Braganca Alves Fernandes, Alexandre Nieuwendam, Antonio Batista PereiraAbstract:Abstract Climate change impacts the biotic and abiotic components of polar ecosystems, affecting the stability of permafrost, active layer thickness, vegetation, and soil. This paper describes the active layer thermal regimes of two adjacent shallow boreholes, under the same soil but with two different vegetations. The study is location in Lions Rump, at King George Island, Maritime Antarctic, one of the most sensitive regions to climate change, located near the climatic limit of Antarctic permafrost. Both sites are a Turbic Cambic Cryosol formed on andesitic basalt, one under moss vegetation (Andreaea gainii, at 85 m a.s.l.) and another under lichen (Usnea sp., at 86 m a.s.l.), located 10 m apart. Ground temperature at same depths (10, 30 and 80 cm), water content at 80 cm depth and air temperature were recorded hourly between March 2009 and February 2011. The two sites showed significant differences in mean annual ground temperature for all depths. The lichen site showed a higher soil temperature amplitude compared to the moss site, with ground surface (10 cm) showing the highest daily temperature in January 2011 (7.3 °C) and the lowest daily temperature in August (− 16.5 °C). The soil temperature at the lichen site closely followed the air temperature trend. The moss site showed a higher water content at the bottommost layer, consistent with the water-saturated, low landscape position. The observed thermal buffering effect under mosses is primarily associated with higher moisture onsite, but a longer duration of the snowpack (not monitored) may also have influenced the results. Active layer thickness was approximately 150 cm at low-lying moss site, and 120 cm at well-drained lichen site. This allows to classify these soils as Cryosols (WRB) or Gelisols (Soil Taxonomy), with evident turbic features.
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micromorphological and microchemical indicators of pedogenesis in ornithogenic cryosols Gelisols of hope bay antarctic peninsula
Geoderma, 2013Co-Authors: Thiago Torres Costa Pereira, Carlos Ernesto Goncalves Reynaud Schaefer, Joao C Ker, Cecilia Calhau Almeida, Ivan C C AlmeidaAbstract:Abstract Micromorphological investigations of Antarctic soils are comparatively scarce, however, they could help understand the genesis of cryogenic soils under extreme polar conditions and different biotic factors. In most areas of Maritime Antarctica, the soil structure is apparently influenced by the local lithology, cryoturbation, guano deposition and reaction of guano solutions. The present study was carried out in Hope Bay, in the northern part of the Antarctic Peninsula, possibly one of the oldest sites of penguin occupation in the region. We describe and analyze the most important micro and sub-microscopic features of selected Ornithogenic Cryosols (Gelisols) from this part of Antarctic Peninsula, representing a transitional climatic zone between the wetter South Shetlands and the much drier Weddell Sea sector. Nine pedons representing the main ornithogenic soils found in ice-free areas of Hope Bay were selected for the micromorphological study. Undisturbed soil blocks were sampled at different depths, ranging between 0 and 30 cm. The microstructure and sub-microstructure were further investigated using a JEOL 8200 and a Zeiss scanning electron microscopes, both coupled with an microprobe (SEM/WDS). These pedons have a very limited surface accumulation of organic matter formed by mosses and lichens, changing abruptly to a mineral phosphatic horizon of bleached colours, and usually hardcemented by ice. A small to medium-sized granular structure is generally observed, with ovoidal, subrounded forms, including several well-defined ornithogenic materials, such as P-rich organic remains, nodular phosphates forms and minute fragments of bone apatite. The chemical composition of ornithogenic materials and phosphatic coatings indicates the presence of discrete forms of taranakite, minyulite, leucophosphite, struvite and fluorapatite, typical of phosphatization process in these soils. Phosphatization and enhanced chemical alteration of the substrate and is one of the main soil-forming process in ornithogenic soils, resulting in P-rich ovoidal aggregates formation. P-rich solutions penetrate desiccation fractures and cleavage planes in large clasts and react preferably with plagioclases. P reacts with Al and Fe to form various amorphous and crystalline P phases. Present day permafrost cementation of deeper phosphate layers indicate that warmer/wetter conditions occurred in the past, during which P was leached downwards and reacted with the rock substrates, developing stable ovoidal aggregates, now incorporated in ice-cemented subsurface horizon.
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geomorphology and soils distribution under paraglacial conditions in an ice free area of admiralty bay king george island antarctica
Catena, 2011Co-Authors: Marcio Rocha Francelino, Carlos Ernesto Goncalves Reynaud Schaefer, Felipe Nogueira Bello Simas, Elpidio Inacio Fernandes Filho, Jose Joao Lelis Leal De Souza, Liovando Marciano Da CostaAbstract:Abstract The main pedological, geomorphological and cryogenic features of Keller Peninsula, part of Admiralty Bay, King George Island, Maritime Antarctica, were mapped and quantified with emphasis on the relationship between the ice retreat process, melt-out, landform development and soil distribution. Moraines, protalus, scree slopes, inactive glacial cirques, uplift marine terraces, biogenic landforms, aretes and Felsenmeer were mapped. Scree slope is the main landform, covering approximately 25% of the peninsula, indicating prominent paraglacial features. Inherited, glacial landforms, such as lateral moraines, highland plateau and exhumed U shaped-valleys, are now being exposed in north Keller by ice shrinkage of former ice protecting cover. Landforms influenced soil formation and stability. Cryosols and Leptosols (WRB) roughly corresponding to Gelisols and Entisols (SSS), respectively, are the most common soil classes, with an overall tendency of absent permafrost in the coastal areas, changing to sporadic permafrost at mid-slope, and discontinuous permafrost with greater altitude and substrate stability.
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ornithogenic Gelisols cryosols from maritime antarctica
Soil Science Society of America Journal, 2006Co-Authors: Roberto Ferreira Machado Michel, Carlos Ernesto Goncalves Reynaud Schaefer, Luis Eduardo Dias, Felipe Nogueira Bello Simas, Vinicius De Melo Benites, Eduardo De Sa MendoncaAbstract:In terrestrial ecosystems of Maritime Antarctica (King George Island), the transference of primary marine production to the land promoted by penguins (Pygoscelis adeliae) and other birds, appears to influence soil formation and chemical weathering to a greater extent than formerly predicted. This paper summarizes the results of pedological investigations on the vicinity of the American Pieter J. Lenie Field Station (62°10' S, 58°28' W), discussing soil formation processes related to vegetation succession in the studied area. Soil organic matter (SOM) accumulation and associated phosphatization are marked soil-forming processes in ice-free areas once colonized by penguins. Also there is a high correlation between soil development and vegetation patterns. Nutrient supply in these cryogenic soils is affected by low pH following nitrification and high contents of P, K, Ca, and Mg due to seabirds' inputs. Lithic Umbriturbels and Glacic Haploturbels are the most common omithogenic soils, followed by Lithic Fibristels and Psammentic Aquiturbels. In all soils phosphatization and omithogenesis occurs in varying degrees. However, the recent Gelisols order of Soil Taxonomy does not consider the influence of ornithogenesis or phosphatization in its framework, so that a more detailed classification of such soils is not possible.
Thiago Torres Costa Pereira - One of the best experts on this subject based on the ideXlab platform.
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active layer thermal regime at different vegetation covers at lions rump king george island maritime antarctica
Geomorphology, 2014Co-Authors: Ivan C C Almeida, Carlos Ernesto Goncalves Reynaud Schaefer, Thiago Torres Costa Pereira, Raphael Braganca Alves Fernandes, Alexandre Nieuwendam, Antonio Batista PereiraAbstract:Abstract Climate change impacts the biotic and abiotic components of polar ecosystems, affecting the stability of permafrost, active layer thickness, vegetation, and soil. This paper describes the active layer thermal regimes of two adjacent shallow boreholes, under the same soil but with two different vegetations. The study is location in Lions Rump, at King George Island, Maritime Antarctic, one of the most sensitive regions to climate change, located near the climatic limit of Antarctic permafrost. Both sites are a Turbic Cambic Cryosol formed on andesitic basalt, one under moss vegetation (Andreaea gainii, at 85 m a.s.l.) and another under lichen (Usnea sp., at 86 m a.s.l.), located 10 m apart. Ground temperature at same depths (10, 30 and 80 cm), water content at 80 cm depth and air temperature were recorded hourly between March 2009 and February 2011. The two sites showed significant differences in mean annual ground temperature for all depths. The lichen site showed a higher soil temperature amplitude compared to the moss site, with ground surface (10 cm) showing the highest daily temperature in January 2011 (7.3 °C) and the lowest daily temperature in August (− 16.5 °C). The soil temperature at the lichen site closely followed the air temperature trend. The moss site showed a higher water content at the bottommost layer, consistent with the water-saturated, low landscape position. The observed thermal buffering effect under mosses is primarily associated with higher moisture onsite, but a longer duration of the snowpack (not monitored) may also have influenced the results. Active layer thickness was approximately 150 cm at low-lying moss site, and 120 cm at well-drained lichen site. This allows to classify these soils as Cryosols (WRB) or Gelisols (Soil Taxonomy), with evident turbic features.
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micromorphological and microchemical indicators of pedogenesis in ornithogenic cryosols Gelisols of hope bay antarctic peninsula
Geoderma, 2013Co-Authors: Thiago Torres Costa Pereira, Carlos Ernesto Goncalves Reynaud Schaefer, Joao C Ker, Cecilia Calhau Almeida, Ivan C C AlmeidaAbstract:Abstract Micromorphological investigations of Antarctic soils are comparatively scarce, however, they could help understand the genesis of cryogenic soils under extreme polar conditions and different biotic factors. In most areas of Maritime Antarctica, the soil structure is apparently influenced by the local lithology, cryoturbation, guano deposition and reaction of guano solutions. The present study was carried out in Hope Bay, in the northern part of the Antarctic Peninsula, possibly one of the oldest sites of penguin occupation in the region. We describe and analyze the most important micro and sub-microscopic features of selected Ornithogenic Cryosols (Gelisols) from this part of Antarctic Peninsula, representing a transitional climatic zone between the wetter South Shetlands and the much drier Weddell Sea sector. Nine pedons representing the main ornithogenic soils found in ice-free areas of Hope Bay were selected for the micromorphological study. Undisturbed soil blocks were sampled at different depths, ranging between 0 and 30 cm. The microstructure and sub-microstructure were further investigated using a JEOL 8200 and a Zeiss scanning electron microscopes, both coupled with an microprobe (SEM/WDS). These pedons have a very limited surface accumulation of organic matter formed by mosses and lichens, changing abruptly to a mineral phosphatic horizon of bleached colours, and usually hardcemented by ice. A small to medium-sized granular structure is generally observed, with ovoidal, subrounded forms, including several well-defined ornithogenic materials, such as P-rich organic remains, nodular phosphates forms and minute fragments of bone apatite. The chemical composition of ornithogenic materials and phosphatic coatings indicates the presence of discrete forms of taranakite, minyulite, leucophosphite, struvite and fluorapatite, typical of phosphatization process in these soils. Phosphatization and enhanced chemical alteration of the substrate and is one of the main soil-forming process in ornithogenic soils, resulting in P-rich ovoidal aggregates formation. P-rich solutions penetrate desiccation fractures and cleavage planes in large clasts and react preferably with plagioclases. P reacts with Al and Fe to form various amorphous and crystalline P phases. Present day permafrost cementation of deeper phosphate layers indicate that warmer/wetter conditions occurred in the past, during which P was leached downwards and reacted with the rock substrates, developing stable ovoidal aggregates, now incorporated in ice-cemented subsurface horizon.
Ivan C C Almeida - One of the best experts on this subject based on the ideXlab platform.
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active layer thermal regime at different vegetation covers at lions rump king george island maritime antarctica
Geomorphology, 2014Co-Authors: Ivan C C Almeida, Carlos Ernesto Goncalves Reynaud Schaefer, Thiago Torres Costa Pereira, Raphael Braganca Alves Fernandes, Alexandre Nieuwendam, Antonio Batista PereiraAbstract:Abstract Climate change impacts the biotic and abiotic components of polar ecosystems, affecting the stability of permafrost, active layer thickness, vegetation, and soil. This paper describes the active layer thermal regimes of two adjacent shallow boreholes, under the same soil but with two different vegetations. The study is location in Lions Rump, at King George Island, Maritime Antarctic, one of the most sensitive regions to climate change, located near the climatic limit of Antarctic permafrost. Both sites are a Turbic Cambic Cryosol formed on andesitic basalt, one under moss vegetation (Andreaea gainii, at 85 m a.s.l.) and another under lichen (Usnea sp., at 86 m a.s.l.), located 10 m apart. Ground temperature at same depths (10, 30 and 80 cm), water content at 80 cm depth and air temperature were recorded hourly between March 2009 and February 2011. The two sites showed significant differences in mean annual ground temperature for all depths. The lichen site showed a higher soil temperature amplitude compared to the moss site, with ground surface (10 cm) showing the highest daily temperature in January 2011 (7.3 °C) and the lowest daily temperature in August (− 16.5 °C). The soil temperature at the lichen site closely followed the air temperature trend. The moss site showed a higher water content at the bottommost layer, consistent with the water-saturated, low landscape position. The observed thermal buffering effect under mosses is primarily associated with higher moisture onsite, but a longer duration of the snowpack (not monitored) may also have influenced the results. Active layer thickness was approximately 150 cm at low-lying moss site, and 120 cm at well-drained lichen site. This allows to classify these soils as Cryosols (WRB) or Gelisols (Soil Taxonomy), with evident turbic features.
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micromorphological and microchemical indicators of pedogenesis in ornithogenic cryosols Gelisols of hope bay antarctic peninsula
Geoderma, 2013Co-Authors: Thiago Torres Costa Pereira, Carlos Ernesto Goncalves Reynaud Schaefer, Joao C Ker, Cecilia Calhau Almeida, Ivan C C AlmeidaAbstract:Abstract Micromorphological investigations of Antarctic soils are comparatively scarce, however, they could help understand the genesis of cryogenic soils under extreme polar conditions and different biotic factors. In most areas of Maritime Antarctica, the soil structure is apparently influenced by the local lithology, cryoturbation, guano deposition and reaction of guano solutions. The present study was carried out in Hope Bay, in the northern part of the Antarctic Peninsula, possibly one of the oldest sites of penguin occupation in the region. We describe and analyze the most important micro and sub-microscopic features of selected Ornithogenic Cryosols (Gelisols) from this part of Antarctic Peninsula, representing a transitional climatic zone between the wetter South Shetlands and the much drier Weddell Sea sector. Nine pedons representing the main ornithogenic soils found in ice-free areas of Hope Bay were selected for the micromorphological study. Undisturbed soil blocks were sampled at different depths, ranging between 0 and 30 cm. The microstructure and sub-microstructure were further investigated using a JEOL 8200 and a Zeiss scanning electron microscopes, both coupled with an microprobe (SEM/WDS). These pedons have a very limited surface accumulation of organic matter formed by mosses and lichens, changing abruptly to a mineral phosphatic horizon of bleached colours, and usually hardcemented by ice. A small to medium-sized granular structure is generally observed, with ovoidal, subrounded forms, including several well-defined ornithogenic materials, such as P-rich organic remains, nodular phosphates forms and minute fragments of bone apatite. The chemical composition of ornithogenic materials and phosphatic coatings indicates the presence of discrete forms of taranakite, minyulite, leucophosphite, struvite and fluorapatite, typical of phosphatization process in these soils. Phosphatization and enhanced chemical alteration of the substrate and is one of the main soil-forming process in ornithogenic soils, resulting in P-rich ovoidal aggregates formation. P-rich solutions penetrate desiccation fractures and cleavage planes in large clasts and react preferably with plagioclases. P reacts with Al and Fe to form various amorphous and crystalline P phases. Present day permafrost cementation of deeper phosphate layers indicate that warmer/wetter conditions occurred in the past, during which P was leached downwards and reacted with the rock substrates, developing stable ovoidal aggregates, now incorporated in ice-cemented subsurface horizon.
Charles D. Koven - One of the best experts on this subject based on the ideXlab platform.
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a new data set for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region
Earth System Science Data, 2013Co-Authors: Gustaf Hugelius, James G. Bockheim, Jennifer W. Harden, P. Camill, Torre Jorgenson, Bo Elberling, Guido Grosse, Kevin T M Johnson, Charles D. KovenAbstract:Abstract. High-latitude terrestrial ecosystems are key components in the global carbon cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (a total area of 18.7 × 106 km2). The NCSCD is a geographical information system (GIS) data set that has been constructed using harmonized regional soil classification maps together with pedon data from the northern permafrost region. Previously, the NCSCD has been used to calculate SOC storage to the reference depths 0–30 cm and 0–100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100–300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this deeper SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon data set for SOC storage (kg C m−2) in deep soils of the northern circumpolar permafrost regions, with separate data sets for the 100–200 cm (524 pedons) and 200–300 cm (356 pedons) depth ranges. These pedons have been grouped into the North American and Eurasian sectors and the mean SOC storage for different soil taxa (subdivided into Gelisols including the sub-orders Histels, Turbels, Orthels, permafrost-free Histosols, and permafrost-free mineral soil orders) has been added to the updated NCSCDv2. The updated version of the data set is freely available online in different file formats and spatial resolutions that enable spatially explicit applications in GIS mapping and terrestrial ecosystem models. While this newly compiled data set adds to our knowledge of SOC in the 100–300 cm depth range, it also reveals that large uncertainties remain. Identified data gaps include spatial coverage of deep (> 100 cm) pedons in many regions as well as the spatial extent of areas with thin soils overlying bedrock and the quantity and distribution of massive ground ice. An open access data-portal for the pedon data set and the GIS-data sets is available online at http://bolin.su.se/data/ncscd/ . The NCSCDv2 data set has a digital object identifier ( doi:10.5879/ECDS/00000002 ).
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A new data set for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region
Copernicus Publications, 2013Co-Authors: Gustaf Hugelius, Charles D. Koven, P. Camill, Bo Elberling, Guido Grosse, J. G. Bockheim, J. W. Harden, K. Johnson, T. Jorgenson, Peter KuhryAbstract:High-latitude terrestrial ecosystems are key components in the global carbon cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (a total area of 18.7 × 106 km2). The NCSCD is a geographical information system (GIS) data set that has been constructed using harmonized regional soil classification maps together with pedon data from the northern permafrost region. Previously, the NCSCD has been used to calculate SOC storage to the reference depths 0–30 cm and 0–100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100–300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this deeper SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon data set for SOC storage (kg C m−2) in deep soils of the northern circumpolar permafrost regions, with separate data sets for the 100–200 cm (524 pedons) and 200–300 cm (356 pedons) depth ranges. These pedons have been grouped into the North American and Eurasian sectors and the mean SOC storage for different soil taxa (subdivided into Gelisols including the sub-orders Histels, Turbels, Orthels, permafrost-free Histosols, and permafrost-free mineral soil orders) has been added to the updated NCSCDv2. The updated version of the data set is freely available online in different file formats and spatial resolutions that enable spatially explicit applications in GIS mapping and terrestrial ecosystem models. While this newly compiled data set adds to our knowledge of SOC in the 100–300 cm depth range, it also reveals that large uncertainties remain. Identified data gaps include spatial coverage of deep (> 100 cm) pedons in many regions as well as the spatial extent of areas with thin soils overlying bedrock and the quantity and distribution of massive ground ice. An open access data-portal for the pedon data set and the GIS-data sets is available online at http://bolin.su.se/data/ncscd/. The NCSCDv2 data set has a digital object identifier (doi:10.5879/ECDS/00000002)
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Field information links permafrost carbon to physical vulnerabilities of thawing
Geophysical Research Letters, 2012Co-Authors: Jennifer W. Harden, Chienlu Ping, Charles D. Koven, Gustaf Hugelius, A. David Mcguire, P. Camill, Torre Jorgenson, Peter Kuhry, Gary J. Michaelson, Jonathan A. O'donnellAbstract:Deep soil profiles containing permafrost (Gelisols) were characterized for organic carbon (C) and total nitrogen (N) stocks to 3 m depths. Using the Community Climate System Model (CCSM4) we calcul ...
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Field information links permafrost carbon to physical vulnerabilities of thawing
2012Co-Authors: Jennifer W. Harden, Chienlu Ping, Charles D. Koven, Gustaf Hugelius, P. Camill, Torre Jorgenson, Peter Kuhry, Gary J. Michaelson, David A. Mcguire, Guido GrosseAbstract:[1] Deep soil profiles containing permafrost (Gelisols) were characterized for organic carbon (C) and total nitrogen (N) stocks to 3 m depths. Using the Community Climate System Model (CCSM4) we calculate cumulative distributions of active layer thickness (ALT) under current and future climates. The difference in cumulative ALT distributions over time was multiplied by C and N contents of soil horizons in Gelisol suborders to calculate newly thawed C and N. Thawing ranged from 147 PgC with 10 PgN by 2050 (representative concentration pathway RCP scenario 4.5) to 436 PgC with 29 PgN by 2100 (RCP 8.5). Organic horizons that thaw are vulnerable to combustion, and all horizon types are vulnerable to shifts in hydrology and decomposition. The rates and extent of such losses are unknown and can be further constrained by linking field and modelling approaches. These changes have the potential for strong additional loading to our atmosphere, water resources, and ecosystems
Gustaf Hugelius - One of the best experts on this subject based on the ideXlab platform.
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a new data set for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region
Earth System Science Data, 2013Co-Authors: Gustaf Hugelius, James G. Bockheim, Jennifer W. Harden, P. Camill, Torre Jorgenson, Bo Elberling, Guido Grosse, Kevin T M Johnson, Charles D. KovenAbstract:Abstract. High-latitude terrestrial ecosystems are key components in the global carbon cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (a total area of 18.7 × 106 km2). The NCSCD is a geographical information system (GIS) data set that has been constructed using harmonized regional soil classification maps together with pedon data from the northern permafrost region. Previously, the NCSCD has been used to calculate SOC storage to the reference depths 0–30 cm and 0–100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100–300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this deeper SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon data set for SOC storage (kg C m−2) in deep soils of the northern circumpolar permafrost regions, with separate data sets for the 100–200 cm (524 pedons) and 200–300 cm (356 pedons) depth ranges. These pedons have been grouped into the North American and Eurasian sectors and the mean SOC storage for different soil taxa (subdivided into Gelisols including the sub-orders Histels, Turbels, Orthels, permafrost-free Histosols, and permafrost-free mineral soil orders) has been added to the updated NCSCDv2. The updated version of the data set is freely available online in different file formats and spatial resolutions that enable spatially explicit applications in GIS mapping and terrestrial ecosystem models. While this newly compiled data set adds to our knowledge of SOC in the 100–300 cm depth range, it also reveals that large uncertainties remain. Identified data gaps include spatial coverage of deep (> 100 cm) pedons in many regions as well as the spatial extent of areas with thin soils overlying bedrock and the quantity and distribution of massive ground ice. An open access data-portal for the pedon data set and the GIS-data sets is available online at http://bolin.su.se/data/ncscd/ . The NCSCDv2 data set has a digital object identifier ( doi:10.5879/ECDS/00000002 ).
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A new data set for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region
Copernicus Publications, 2013Co-Authors: Gustaf Hugelius, Charles D. Koven, P. Camill, Bo Elberling, Guido Grosse, J. G. Bockheim, J. W. Harden, K. Johnson, T. Jorgenson, Peter KuhryAbstract:High-latitude terrestrial ecosystems are key components in the global carbon cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (a total area of 18.7 × 106 km2). The NCSCD is a geographical information system (GIS) data set that has been constructed using harmonized regional soil classification maps together with pedon data from the northern permafrost region. Previously, the NCSCD has been used to calculate SOC storage to the reference depths 0–30 cm and 0–100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100–300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this deeper SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon data set for SOC storage (kg C m−2) in deep soils of the northern circumpolar permafrost regions, with separate data sets for the 100–200 cm (524 pedons) and 200–300 cm (356 pedons) depth ranges. These pedons have been grouped into the North American and Eurasian sectors and the mean SOC storage for different soil taxa (subdivided into Gelisols including the sub-orders Histels, Turbels, Orthels, permafrost-free Histosols, and permafrost-free mineral soil orders) has been added to the updated NCSCDv2. The updated version of the data set is freely available online in different file formats and spatial resolutions that enable spatially explicit applications in GIS mapping and terrestrial ecosystem models. While this newly compiled data set adds to our knowledge of SOC in the 100–300 cm depth range, it also reveals that large uncertainties remain. Identified data gaps include spatial coverage of deep (> 100 cm) pedons in many regions as well as the spatial extent of areas with thin soils overlying bedrock and the quantity and distribution of massive ground ice. An open access data-portal for the pedon data set and the GIS-data sets is available online at http://bolin.su.se/data/ncscd/. The NCSCDv2 data set has a digital object identifier (doi:10.5879/ECDS/00000002)
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Field information links permafrost carbon to physical vulnerabilities of thawing
Geophysical Research Letters, 2012Co-Authors: Jennifer W. Harden, Chienlu Ping, Charles D. Koven, Gustaf Hugelius, A. David Mcguire, P. Camill, Torre Jorgenson, Peter Kuhry, Gary J. Michaelson, Jonathan A. O'donnellAbstract:Deep soil profiles containing permafrost (Gelisols) were characterized for organic carbon (C) and total nitrogen (N) stocks to 3 m depths. Using the Community Climate System Model (CCSM4) we calcul ...
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Field information links permafrost carbon to physical vulnerabilities of thawing
2012Co-Authors: Jennifer W. Harden, Chienlu Ping, Charles D. Koven, Gustaf Hugelius, P. Camill, Torre Jorgenson, Peter Kuhry, Gary J. Michaelson, David A. Mcguire, Guido GrosseAbstract:[1] Deep soil profiles containing permafrost (Gelisols) were characterized for organic carbon (C) and total nitrogen (N) stocks to 3 m depths. Using the Community Climate System Model (CCSM4) we calculate cumulative distributions of active layer thickness (ALT) under current and future climates. The difference in cumulative ALT distributions over time was multiplied by C and N contents of soil horizons in Gelisol suborders to calculate newly thawed C and N. Thawing ranged from 147 PgC with 10 PgN by 2050 (representative concentration pathway RCP scenario 4.5) to 436 PgC with 29 PgN by 2100 (RCP 8.5). Organic horizons that thaw are vulnerable to combustion, and all horizon types are vulnerable to shifts in hydrology and decomposition. The rates and extent of such losses are unknown and can be further constrained by linking field and modelling approaches. These changes have the potential for strong additional loading to our atmosphere, water resources, and ecosystems