The Experts below are selected from a list of 38562 Experts worldwide ranked by ideXlab platform
Roberto Orosei - One of the best experts on this subject based on the ideXlab platform.
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Martian underground water detection: Thermal model and simulations of radar signal propagation
Journal of Geophysical Research, 2003Co-Authors: O.b. Shchuko, D. V. Kartashov, Giovanni Picardi, Roberto OroseiAbstract:[1] The thermophysical conditions of ice/water existence in the upper Martian crust have been considered in the frame of a multilayer structurally inhomogeneous geological model. The water even at the equatorial site has been shown to exist only at depths below 1 km for any values of the upper layer emissivity and Internal Flux intensity. The radar signal propagation in the layered inhomogeneous medium has been studied. The possibility of the ice or water existence at deep layers has been considered by analyzing the reflected radar signal in the frequency band 1.9-5.8 MHz.
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Martian underground water detection: Thermal model and simulations of radar signal propagation : Geophysical detection of surface water on Mars
Journal of Geophysical Research, 2003Co-Authors: O.b. Shchuko, D. V. Kartashov, Giovanni Picardi, Roberto OroseiAbstract:The thermophysical conditions of ice/water existence in the upper Martian crust have been considered in the frame of a multilayer structurally inhomogeneous geological model. The water even at the equatorial site has been shown to exist only at depths below 1 km for any values of the upper layer emissivity and Internal Flux intensity. The radar signal propagation in the layered inhomogeneous medium has been studied. The possibility of the ice or water existence at deep layers has been considered by analyzing the reflected radar signal in the frequency band 1.9-5.8 MHz.
Inés González-doncel - One of the best experts on this subject based on the ideXlab platform.
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Xylem and soil CO2 Fluxes in a Quercus pyrenaica Willd. coppice: root respiration increases with clonal size
Annals of Forest Science, 2015Co-Authors: Roberto Salomón, María Valbuena-carabaña, Jesús Rodríguez-calcerrada, Doug Aubrey, Maryanne Mcguire, Robert Teskey, Luis Gil, Inés González-doncelAbstract:Abstract• Key messageXylem and soil CO2Fluxes in coppiced oak forests increase with clonal size, suggesting larger expenditures of energy for root respiration. An imbalance between root demand and shoot production of carbohydrates may contribute to the degradation of abandoned coppices.• ContextOur understanding of root respiration is limited, particularly in root-resprouting species with many stems and a large system of interconnected roots resulting from long-term coppicing.• AimsWe tested the hypothesis that clone size influences the Internal Flux of CO2 dissolved in xylem sap (FT) from roots into the stem and soil CO2 efFlux (FS) as indicators of root respiration. We predicted that large clones would exhibit higher FT per stem and FS than small clones due to larger root system per stem in large clones.• MethodsGenetic analyses were performed to elucidate clonal grouping. FT was measured continuously for 100 days in 16 similar-sized stems of Quercus pyrenaica belonging to two large and two small clones. FS was measured in 20 clones of varying size.• ResultsFT per stem and FS were higher in large clones. FT was 2 % of the root-respired CO2 that diffused through soil to the atmosphere.• ConclusionsRelative to other studies, the contribution of FT to root respiration was very low, pointing to large differences depending on species or site. Higher stem FT and FS in large clones compared with small clones suggest greater carbon consumption by roots in large clones, pointing to a root/shoot biomass and physiological imbalance resulting from long-term coppicing that would partially explain the degradation of currently abandoned stands of Q. pyrenaica.
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Xylem and soil CO_2 Fluxes in a Quercus pyrenaica Willd. coppice: root respiration increases with clonal size
Annals of Forest Science, 2015Co-Authors: Roberto Salomón, María Valbuena-carabaña, Jesús Rodríguez-calcerrada, Doug Aubrey, Maryanne Mcguire, Robert Teskey, Inés González-doncelAbstract:• Key message Xylem and soil CO _ 2 Fluxes in coppiced oak forests increase with clonal size, suggesting larger expenditures of energy for root respiration. An imbalance between root demand and shoot production of carbohydrates may contribute to the degradation of abandoned coppices. • Context Our understanding of root respiration is limited, particularly in root-resprouting species with many stems and a large system of interconnected roots resulting from long-term coppicing. • Aims We tested the hypothesis that clone size influences the Internal Flux of CO_2 dissolved in xylem sap ( F _T) from roots into the stem and soil CO_2 efFlux ( F _S) as indicators of root respiration. We predicted that large clones would exhibit higher F _T per stem and F _S than small clones due to larger root system per stem in large clones. • Methods Genetic analyses were performed to elucidate clonal grouping. F _T was measured continuously for 100 days in 16 similar-sized stems of Quercus pyrenaica belonging to two large and two small clones. F _S was measured in 20 clones of varying size. • Results F _T per stem and F _S were higher in large clones. F _T was 2 % of the root-respired CO_2 that diffused through soil to the atmosphere. • Conclusions Relative to other studies, the contribution of F _T to root respiration was very low, pointing to large differences depending on species or site. Higher stem F _T and F _S in large clones compared with small clones suggest greater carbon consumption by roots in large clones, pointing to a root/shoot biomass and physiological imbalance resulting from long-term coppicing that would partially explain the degradation of currently abandoned stands of Q. pyrenaica .
O.b. Shchuko - One of the best experts on this subject based on the ideXlab platform.
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Martian underground water detection: Thermal model and simulations of radar signal propagation
Journal of Geophysical Research, 2003Co-Authors: O.b. Shchuko, D. V. Kartashov, Giovanni Picardi, Roberto OroseiAbstract:[1] The thermophysical conditions of ice/water existence in the upper Martian crust have been considered in the frame of a multilayer structurally inhomogeneous geological model. The water even at the equatorial site has been shown to exist only at depths below 1 km for any values of the upper layer emissivity and Internal Flux intensity. The radar signal propagation in the layered inhomogeneous medium has been studied. The possibility of the ice or water existence at deep layers has been considered by analyzing the reflected radar signal in the frequency band 1.9-5.8 MHz.
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Martian underground water detection: Thermal model and simulations of radar signal propagation : Geophysical detection of surface water on Mars
Journal of Geophysical Research, 2003Co-Authors: O.b. Shchuko, D. V. Kartashov, Giovanni Picardi, Roberto OroseiAbstract:The thermophysical conditions of ice/water existence in the upper Martian crust have been considered in the frame of a multilayer structurally inhomogeneous geological model. The water even at the equatorial site has been shown to exist only at depths below 1 km for any values of the upper layer emissivity and Internal Flux intensity. The radar signal propagation in the layered inhomogeneous medium has been studied. The possibility of the ice or water existence at deep layers has been considered by analyzing the reflected radar signal in the frequency band 1.9-5.8 MHz.
Roberto Salomón - One of the best experts on this subject based on the ideXlab platform.
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Xylem and soil CO2 Fluxes in a Quercus pyrenaica Willd. coppice: root respiration increases with clonal size
Annals of Forest Science, 2015Co-Authors: Roberto Salomón, María Valbuena-carabaña, Jesús Rodríguez-calcerrada, Doug Aubrey, Maryanne Mcguire, Robert Teskey, Luis Gil, Inés González-doncelAbstract:Abstract• Key messageXylem and soil CO2Fluxes in coppiced oak forests increase with clonal size, suggesting larger expenditures of energy for root respiration. An imbalance between root demand and shoot production of carbohydrates may contribute to the degradation of abandoned coppices.• ContextOur understanding of root respiration is limited, particularly in root-resprouting species with many stems and a large system of interconnected roots resulting from long-term coppicing.• AimsWe tested the hypothesis that clone size influences the Internal Flux of CO2 dissolved in xylem sap (FT) from roots into the stem and soil CO2 efFlux (FS) as indicators of root respiration. We predicted that large clones would exhibit higher FT per stem and FS than small clones due to larger root system per stem in large clones.• MethodsGenetic analyses were performed to elucidate clonal grouping. FT was measured continuously for 100 days in 16 similar-sized stems of Quercus pyrenaica belonging to two large and two small clones. FS was measured in 20 clones of varying size.• ResultsFT per stem and FS were higher in large clones. FT was 2 % of the root-respired CO2 that diffused through soil to the atmosphere.• ConclusionsRelative to other studies, the contribution of FT to root respiration was very low, pointing to large differences depending on species or site. Higher stem FT and FS in large clones compared with small clones suggest greater carbon consumption by roots in large clones, pointing to a root/shoot biomass and physiological imbalance resulting from long-term coppicing that would partially explain the degradation of currently abandoned stands of Q. pyrenaica.
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Xylem and soil CO_2 Fluxes in a Quercus pyrenaica Willd. coppice: root respiration increases with clonal size
Annals of Forest Science, 2015Co-Authors: Roberto Salomón, María Valbuena-carabaña, Jesús Rodríguez-calcerrada, Doug Aubrey, Maryanne Mcguire, Robert Teskey, Inés González-doncelAbstract:• Key message Xylem and soil CO _ 2 Fluxes in coppiced oak forests increase with clonal size, suggesting larger expenditures of energy for root respiration. An imbalance between root demand and shoot production of carbohydrates may contribute to the degradation of abandoned coppices. • Context Our understanding of root respiration is limited, particularly in root-resprouting species with many stems and a large system of interconnected roots resulting from long-term coppicing. • Aims We tested the hypothesis that clone size influences the Internal Flux of CO_2 dissolved in xylem sap ( F _T) from roots into the stem and soil CO_2 efFlux ( F _S) as indicators of root respiration. We predicted that large clones would exhibit higher F _T per stem and F _S than small clones due to larger root system per stem in large clones. • Methods Genetic analyses were performed to elucidate clonal grouping. F _T was measured continuously for 100 days in 16 similar-sized stems of Quercus pyrenaica belonging to two large and two small clones. F _S was measured in 20 clones of varying size. • Results F _T per stem and F _S were higher in large clones. F _T was 2 % of the root-respired CO_2 that diffused through soil to the atmosphere. • Conclusions Relative to other studies, the contribution of F _T to root respiration was very low, pointing to large differences depending on species or site. Higher stem F _T and F _S in large clones compared with small clones suggest greater carbon consumption by roots in large clones, pointing to a root/shoot biomass and physiological imbalance resulting from long-term coppicing that would partially explain the degradation of currently abandoned stands of Q. pyrenaica .
D. V. Kartashov - One of the best experts on this subject based on the ideXlab platform.
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Martian underground water detection: Thermal model and simulations of radar signal propagation
Journal of Geophysical Research, 2003Co-Authors: O.b. Shchuko, D. V. Kartashov, Giovanni Picardi, Roberto OroseiAbstract:[1] The thermophysical conditions of ice/water existence in the upper Martian crust have been considered in the frame of a multilayer structurally inhomogeneous geological model. The water even at the equatorial site has been shown to exist only at depths below 1 km for any values of the upper layer emissivity and Internal Flux intensity. The radar signal propagation in the layered inhomogeneous medium has been studied. The possibility of the ice or water existence at deep layers has been considered by analyzing the reflected radar signal in the frequency band 1.9-5.8 MHz.
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Martian underground water detection: Thermal model and simulations of radar signal propagation : Geophysical detection of surface water on Mars
Journal of Geophysical Research, 2003Co-Authors: O.b. Shchuko, D. V. Kartashov, Giovanni Picardi, Roberto OroseiAbstract:The thermophysical conditions of ice/water existence in the upper Martian crust have been considered in the frame of a multilayer structurally inhomogeneous geological model. The water even at the equatorial site has been shown to exist only at depths below 1 km for any values of the upper layer emissivity and Internal Flux intensity. The radar signal propagation in the layered inhomogeneous medium has been studied. The possibility of the ice or water existence at deep layers has been considered by analyzing the reflected radar signal in the frequency band 1.9-5.8 MHz.