The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

Jose L Espinar - One of the best experts on this subject based on the ideXlab platform.

  • the impact of vertic Soil Cracks on submerged macrophyte diaspore bank depth distribution in mediterranean temporary wetlands
    Aquatic Botany, 2007
    Co-Authors: Jose L Espinar, Luis Clemente
    Abstract:

    Abstract In temporary wetlands, a majority of diaspores are located in the upper layers of the Soil. In general, it is assumed that the vertical movement of diaspores is caused by animal disturbance, and that reduction in this activity concentrates the diaspores in the topSoil. The occurrence of seasonal Cracks and the dispersion of topSoil during dry periods are processes that have been underestimated in diaspore bank studies. Our results indicated that diaspore size can partially explain the density of diaspores of submerged macrophytes observed at four discrete Soil depths in Donana National Park temporary marshes (SW Spain). The top layers of the Soil exhibit the largest number of species. Spore density of Riella spp., a liverwort, increases with depth, creating an important reserve of viable diaspores in deep Soil. Downward movement of diaspores in Soil Cracks during dry periods, and the extended longevity of Riella diaspores together explain this inverse depth distribution.

  • Short communication The impact of vertic Soil Cracks on submerged macrophyte diaspore bank depth distribution in Mediterranean temporary wetlands
    2007
    Co-Authors: Jose L Espinar, Luis Clemente
    Abstract:

    AbstractIn temporary wetlands, a majority of diaspores are located in the upper layers of the Soil. In general, it is assumed that the vertical movement ofdiaspores is caused by animal disturbance, and that reduction in this activity concentrates the diaspores in the topSoil. The occurrence of seasonalCracks and the dispersion of topSoil during dry periods are processes that have been underestimated in diaspore bank studies. Our results indicatedthat diaspore size can partially explain the density of diaspores of submerged macrophytes observed at four discrete Soil depths in Don˜ana NationalPark temporary marshes (SW Spain). The top layers of the Soil exhibit the largest number of species. Spore density of Riella spp., a liverwort,increases with depth, creating an important reserve of viable diaspores in deep Soil. Downward movement of diaspores in Soil Cracks during dryperiods, and the extended longevity of Riella diaspores together explain this inverse depth distribution.# 2007 Elsevier B.V. All rights reserved.

  • The impact of vertic Soil Cracks on submerged macrophyte diaspore bank depth distribution in Mediterranean temporary wetlands
    Aquatic Botany, 2007
    Co-Authors: Jose L Espinar, Luis Clemente
    Abstract:

    4 pages, 2 tables, 18 references. We thank J.M. Espinar and E. Gutiérrez for field and laboratory assistance, and L.V. García for help with Soil salinity data. Thanks to E.A. Middleton and M.S. Ross for the critical\ud review of the manuscript.Director del trabajo: Espinar, José L.In temporary wetlands, a majority of diaspores are located in the upper layers of the Soil. In general, it is assumed that the vertical movement of diaspores is caused by animal disturbance, and that reduction in this activity concentrates the diaspores in the topSoil. The occurrence of seasonal\ud Cracks and the dispersion of topSoil during dry periods are processes that have been underestimated in diaspore bank studies. Our results indicated that diaspore size can partially explain the density of diaspores of submerged macrophytes observed at four discrete Soil depths in Doñana National\ud Park temporary marshes (SW Spain). The top layers of the Soil exhibit the largest number of species. Spore density of Riella spp., a liverwort, increases with depth, creating an important reserve of viable diaspores in deep Soil. Downward movement of diaspores in Soil Cracks during dry\ud periods, and the extended longevity of Riella diaspores together explain this inverse depth distribution.Financial support comes from the\ud Spanish Ministry of the Environment (MMA, project 05/99).Peer reviewe

  • Timing of seed dispersal generates a bimodal seed bank depth distribution
    American journal of botany, 2005
    Co-Authors: Jose L Espinar, Ken Thompson, Luis V. García
    Abstract:

    The density of Soil seed banks is normally highest at the Soil surface and declines monotonically with depth. Sometimes, for a variety of reasons, peak density occurs below the surface but, except in severely disturbed Soils, it is generally true that deeper seeds are older. In seasonally dry habitats that develop deep Soil Cracks during the dry season, it is possible that some seeds fall down Cracks and rapidly become deeply buried. We investigated this possibility for three dominant clonal perennials ( Scirpus maritimus, S. litoralis, )

Xiaoqin Lei - One of the best experts on this subject based on the ideXlab platform.

  • seismic stability analysis of gravity retaining wall supporting c φ Soil with Cracks
    Soils and Foundations, 2019
    Co-Authors: Shuxi Zhao, Qiwei Yan, Xiaoqin Lei
    Abstract:

    Abstract This article presents an analytical approach for the seismic stability analysis of gravity retaining wall with c–φ backfill Soil. Cracks which are pre-existing (open before the collapse) and are form as part of slope collapse are considered. For a translational failure mechanism assumed, formulas are provided to calculate directly the yield acceleration and the inclination of failure surface. Factors such as Cracks and Cracks opening, wall back inclination, Soil-wall friction, backfill slope are easily to be coupled into the formulations. Both the depth and most adverse location of the crack can be determined from the optimization procedure. Comparisons are made with existing methods and the influences of Cracks opening are discussed. The influence of a crack presence on seismic stability of Soil-wall system is distinct and pre-existing (opened) Cracks have more adverse effect.

  • Seismic stability analysis of gravity retaining wall supporting c–φ Soil with Cracks
    Soils and Foundations, 2019
    Co-Authors: Shuxi Zhao, Qiwei Yan, Xiaoqin Lei
    Abstract:

    Abstract This article presents an analytical approach for the seismic stability analysis of gravity retaining wall with c–φ backfill Soil. Cracks which are pre-existing (open before the collapse) and are form as part of slope collapse are considered. For a translational failure mechanism assumed, formulas are provided to calculate directly the yield acceleration and the inclination of failure surface. Factors such as Cracks and Cracks opening, wall back inclination, Soil-wall friction, backfill slope are easily to be coupled into the formulations. Both the depth and most adverse location of the crack can be determined from the optimization procedure. Comparisons are made with existing methods and the influences of Cracks opening are discussed. The influence of a crack presence on seismic stability of Soil-wall system is distinct and pre-existing (opened) Cracks have more adverse effect.

Luis Clemente - One of the best experts on this subject based on the ideXlab platform.

  • the impact of vertic Soil Cracks on submerged macrophyte diaspore bank depth distribution in mediterranean temporary wetlands
    Aquatic Botany, 2007
    Co-Authors: Jose L Espinar, Luis Clemente
    Abstract:

    Abstract In temporary wetlands, a majority of diaspores are located in the upper layers of the Soil. In general, it is assumed that the vertical movement of diaspores is caused by animal disturbance, and that reduction in this activity concentrates the diaspores in the topSoil. The occurrence of seasonal Cracks and the dispersion of topSoil during dry periods are processes that have been underestimated in diaspore bank studies. Our results indicated that diaspore size can partially explain the density of diaspores of submerged macrophytes observed at four discrete Soil depths in Donana National Park temporary marshes (SW Spain). The top layers of the Soil exhibit the largest number of species. Spore density of Riella spp., a liverwort, increases with depth, creating an important reserve of viable diaspores in deep Soil. Downward movement of diaspores in Soil Cracks during dry periods, and the extended longevity of Riella diaspores together explain this inverse depth distribution.

  • Short communication The impact of vertic Soil Cracks on submerged macrophyte diaspore bank depth distribution in Mediterranean temporary wetlands
    2007
    Co-Authors: Jose L Espinar, Luis Clemente
    Abstract:

    AbstractIn temporary wetlands, a majority of diaspores are located in the upper layers of the Soil. In general, it is assumed that the vertical movement ofdiaspores is caused by animal disturbance, and that reduction in this activity concentrates the diaspores in the topSoil. The occurrence of seasonalCracks and the dispersion of topSoil during dry periods are processes that have been underestimated in diaspore bank studies. Our results indicatedthat diaspore size can partially explain the density of diaspores of submerged macrophytes observed at four discrete Soil depths in Don˜ana NationalPark temporary marshes (SW Spain). The top layers of the Soil exhibit the largest number of species. Spore density of Riella spp., a liverwort,increases with depth, creating an important reserve of viable diaspores in deep Soil. Downward movement of diaspores in Soil Cracks during dryperiods, and the extended longevity of Riella diaspores together explain this inverse depth distribution.# 2007 Elsevier B.V. All rights reserved.

  • The impact of vertic Soil Cracks on submerged macrophyte diaspore bank depth distribution in Mediterranean temporary wetlands
    Aquatic Botany, 2007
    Co-Authors: Jose L Espinar, Luis Clemente
    Abstract:

    4 pages, 2 tables, 18 references. We thank J.M. Espinar and E. Gutiérrez for field and laboratory assistance, and L.V. García for help with Soil salinity data. Thanks to E.A. Middleton and M.S. Ross for the critical\ud review of the manuscript.Director del trabajo: Espinar, José L.In temporary wetlands, a majority of diaspores are located in the upper layers of the Soil. In general, it is assumed that the vertical movement of diaspores is caused by animal disturbance, and that reduction in this activity concentrates the diaspores in the topSoil. The occurrence of seasonal\ud Cracks and the dispersion of topSoil during dry periods are processes that have been underestimated in diaspore bank studies. Our results indicated that diaspore size can partially explain the density of diaspores of submerged macrophytes observed at four discrete Soil depths in Doñana National\ud Park temporary marshes (SW Spain). The top layers of the Soil exhibit the largest number of species. Spore density of Riella spp., a liverwort, increases with depth, creating an important reserve of viable diaspores in deep Soil. Downward movement of diaspores in Soil Cracks during dry\ud periods, and the extended longevity of Riella diaspores together explain this inverse depth distribution.Financial support comes from the\ud Spanish Ministry of the Environment (MMA, project 05/99).Peer reviewe

Sara Beavis - One of the best experts on this subject based on the ideXlab platform.

  • Structural controls on the orientation of erosion gullies in mid-western New South Wales, Australia
    Geomorphology, 2000
    Co-Authors: Sara Beavis
    Abstract:

    Abstract The role of geology in determining the drainage network of gullying has been evaluated by quantitative methods of analysis. At gully erosion sites in New South Wales, field evidence suggests that Soil Cracks are sites of preferential flow and erosion at both the surface and subsurface. Soil fabric and rock structure and weathering studies were undertaken to establish the inheritance of Soil Cracks from the underlying parent material. Gully orientation was correlated with the strike of joints and bedding planes in a range of rock materials, including sedimentary, intrusive and extrusive igneous, and thermal and regional metamorphic rocks. These units vary not only in terms of mineralogy but also in degree of weathering. However, all are steeply dipping structures (usually exceeding 60°). Correlations exist between gully orientation and joints in the underlying material, but the strength of the relationship varies according to the parent material. In the Ordovician hornfels, where no correlation between joints and gully orientation occurred, the evidence showed that gullying was controlled by faulting along the hornfels–granite boundary. These relationships support the view that throughflow processes are dominant in the development of gullies, since convergence of runoff would not be expected to align with subsurface Soil discontinuities.

Shuxi Zhao - One of the best experts on this subject based on the ideXlab platform.

  • seismic stability analysis of gravity retaining wall supporting c φ Soil with Cracks
    Soils and Foundations, 2019
    Co-Authors: Shuxi Zhao, Qiwei Yan, Xiaoqin Lei
    Abstract:

    Abstract This article presents an analytical approach for the seismic stability analysis of gravity retaining wall with c–φ backfill Soil. Cracks which are pre-existing (open before the collapse) and are form as part of slope collapse are considered. For a translational failure mechanism assumed, formulas are provided to calculate directly the yield acceleration and the inclination of failure surface. Factors such as Cracks and Cracks opening, wall back inclination, Soil-wall friction, backfill slope are easily to be coupled into the formulations. Both the depth and most adverse location of the crack can be determined from the optimization procedure. Comparisons are made with existing methods and the influences of Cracks opening are discussed. The influence of a crack presence on seismic stability of Soil-wall system is distinct and pre-existing (opened) Cracks have more adverse effect.

  • Seismic stability analysis of gravity retaining wall supporting c–φ Soil with Cracks
    Soils and Foundations, 2019
    Co-Authors: Shuxi Zhao, Qiwei Yan, Xiaoqin Lei
    Abstract:

    Abstract This article presents an analytical approach for the seismic stability analysis of gravity retaining wall with c–φ backfill Soil. Cracks which are pre-existing (open before the collapse) and are form as part of slope collapse are considered. For a translational failure mechanism assumed, formulas are provided to calculate directly the yield acceleration and the inclination of failure surface. Factors such as Cracks and Cracks opening, wall back inclination, Soil-wall friction, backfill slope are easily to be coupled into the formulations. Both the depth and most adverse location of the crack can be determined from the optimization procedure. Comparisons are made with existing methods and the influences of Cracks opening are discussed. The influence of a crack presence on seismic stability of Soil-wall system is distinct and pre-existing (opened) Cracks have more adverse effect.