The Experts below are selected from a list of 60774 Experts worldwide ranked by ideXlab platform

Carol G Wells - One of the best experts on this subject based on the ideXlab platform.

  • Rapid Accumulation and turnover of soil carbon in a re establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil <1%, of the carbon accretion. Despite high carbon inputs to the mineral soil, carbon sequestration was limited by Rapid decomposition, facilitated by the coarse soil texture and low-activity clay mineralogy.

  • Rapid Accumulation and turnover of soil carbon in a re-establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil

Daniel Richter - One of the best experts on this subject based on the ideXlab platform.

  • Rapid Accumulation and turnover of soil carbon in a re establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil <1%, of the carbon accretion. Despite high carbon inputs to the mineral soil, carbon sequestration was limited by Rapid decomposition, facilitated by the coarse soil texture and low-activity clay mineralogy.

  • Rapid Accumulation and turnover of soil carbon in a re-establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil

Michael T Brett - One of the best experts on this subject based on the ideXlab platform.

  • diet switching experiments show Rapid Accumulation and preferential retention of highly unsaturated fatty acids in daphnia
    Oikos, 2011
    Co-Authors: Sami J Taipale, Martin J Kainz, Michael T Brett
    Abstract:

    Zooplankton transfer ecologically important fatty acids (FA) from their diets to upper trophic levels. We used diet-switching experiments with 13 C-labeled food sources to determine the time scale at which dietary uptake is manifested in the FA profi les of Daphnia magna . Daphnia dramatically shifted their FA composition in response to diet change within only four days, however Daphnia switched from a high quality (i.e. Cryptomonas ) to a moderate quality ( Scenedesmus ) diet retained the most physiologically important FA from their original diet source even after 14 days. In particular, Daphnia exhibited long-term retention of eicosapentaenoic (EPA; 20:5 ω 3) and arachidonic acid (ARA; 20:4 ω 6) when switched from Cryptomonas to Scenedesmus . Similarly, when switched from Scenedesmus to Cryptomonas , Daphnia took up a high proportion of EPA and ARA after only two days. Th e phospholipid fatty acid (PLFA) fraction in Daphnia was preferentially enriched with stearic (18:0), oleic (18:1 ω 9), and linoleic acid (LIN; 18:2 ω 6). In contrast with studies of marine copepods, dietary FA also strongly aff ected the PLFA composition (structural lipids) of Daphnia . Results of δ 13 C signatures of individual FA provided evidence of elongation and desaturation of α -linolenic (ALA; 18:3 ω 3) or stearidonic acid (SDA; 18:4 ω 3) to EPA 10 days after a diet switch to EPA-defi cient Scenedesmus . Diff erences in the ARA content of Daphnia fed Cryptomonas and Scenedesmus suggest Daphnia consuming Cryptomonas synthesized ARA via retroconversion of ω 6-docosapentaenoic acid ( ω 6-DPA; 22:5 ω 6). Daphnia preferentially accumulate and retain, as well as bioconvert, those FA that are also most physiologically important for fi sh production. Our results also indicate Daphnia FA composition responds to their diet on a short temporal scale and analyses of lipid biomarkers in zooplankton provide strong insights into the food sources that support their production.

  • Diet‐switching experiments show Rapid Accumulation and preferential retention of highly unsaturated fatty acids in Daphnia
    Oikos, 2011
    Co-Authors: Sami J Taipale, Martin J Kainz, Michael T Brett
    Abstract:

    Zooplankton transfer ecologically important fatty acids (FA) from their diets to upper trophic levels. We used diet-switching experiments with 13 C-labeled food sources to determine the time scale at which dietary uptake is manifested in the FA profi les of Daphnia magna . Daphnia dramatically shifted their FA composition in response to diet change within only four days, however Daphnia switched from a high quality (i.e. Cryptomonas ) to a moderate quality ( Scenedesmus ) diet retained the most physiologically important FA from their original diet source even after 14 days. In particular, Daphnia exhibited long-term retention of eicosapentaenoic (EPA; 20:5 ω 3) and arachidonic acid (ARA; 20:4 ω 6) when switched from Cryptomonas to Scenedesmus . Similarly, when switched from Scenedesmus to Cryptomonas , Daphnia took up a high proportion of EPA and ARA after only two days. Th e phospholipid fatty acid (PLFA) fraction in Daphnia was preferentially enriched with stearic (18:0), oleic (18:1 ω 9), and linoleic acid (LIN; 18:2 ω 6). In contrast with studies of marine copepods, dietary FA also strongly aff ected the PLFA composition (structural lipids) of Daphnia . Results of δ 13 C signatures of individual FA provided evidence of elongation and desaturation of α -linolenic (ALA; 18:3 ω 3) or stearidonic acid (SDA; 18:4 ω 3) to EPA 10 days after a diet switch to EPA-defi cient Scenedesmus . Diff erences in the ARA content of Daphnia fed Cryptomonas and Scenedesmus suggest Daphnia consuming Cryptomonas synthesized ARA via retroconversion of ω 6-docosapentaenoic acid ( ω 6-DPA; 22:5 ω 6). Daphnia preferentially accumulate and retain, as well as bioconvert, those FA that are also most physiologically important for fi sh production. Our results also indicate Daphnia FA composition responds to their diet on a short temporal scale and analyses of lipid biomarkers in zooplankton provide strong insights into the food sources that support their production.

Daniel Markewitz - One of the best experts on this subject based on the ideXlab platform.

  • Rapid Accumulation and turnover of soil carbon in a re establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil <1%, of the carbon accretion. Despite high carbon inputs to the mineral soil, carbon sequestration was limited by Rapid decomposition, facilitated by the coarse soil texture and low-activity clay mineralogy.

  • Rapid Accumulation and turnover of soil carbon in a re-establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil

Susan E Trumbore - One of the best experts on this subject based on the ideXlab platform.

  • Rapid Accumulation and turnover of soil carbon in a re establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil <1%, of the carbon accretion. Despite high carbon inputs to the mineral soil, carbon sequestration was limited by Rapid decomposition, facilitated by the coarse soil texture and low-activity clay mineralogy.

  • Rapid Accumulation and turnover of soil carbon in a re-establishing forest
    Nature, 1999
    Co-Authors: Daniel Richter, Daniel Markewitz, Susan E Trumbore, Carol G Wells
    Abstract:

    Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics. The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 1015 gyr-1), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter. Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited. Here we present a four-decade-long field study of carbon Accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA. Newly accumulated carbon is tracked by its distinctive 14C signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric 14CO2 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest Rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil