@article{vanSchaikPalmKlausetal.2014,
  author    = {van Schaik, Loes and Palm, Juliane and Klaus, Julian and Zehe, Erwin and Schroeder, Boris},
  title     = {Linking spatial earthworm distribution to macropore numbers and hydrological effectiveness},
  series = {Ecohydrology : ecosystems, land and water process interactions, ecohydrogeomorphology},
  volume    = {7},
  journal   = {Ecohydrology : ecosystems, land and water process interactions, ecohydrogeomorphology},
  number    = {2},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1936-0584},
  doi       = {10.1002/eco.1358},
  pages     = {401 -- 408},
  year      = {2014},
  abstract  = {Due to its high spatial and temporal variability, preferential flow is difficult to measure and quantify. Earthworms create macropores that provide common pathways for preferential flow. Therefore in this article, we link earthworm abundance to macropore numbers and hydrological effectiveness, with the future aim to use species distribution models of earthworms for the spatial parameterization of preferential flow. Earthworms are generally categorized into three ecological types with varying burrowing behaviour, resulting in a different impact on soil hydrological processes. Therefore, we studied the relationships between the abundance of the earthworm ecological types and macropores of different size classes and in different soil depths. The abundance and biomass of earthworms were well correlated to different sizes of macropores in different soil depths. This is mainly the case for the larger, vertically oriented macropores (>6mm diameter), which are generally connected to the soil surface and hydrologically most effective. The correlation of total earthworm biomass and macropores ranges from 072 to 089 for different soil depths. Although there is quite some variation in infiltration patterns, infiltration from macropores into the matrix is profile-specific, as it varies strongly between profiles, but not within one profile. Macropore coating seems to have a larger effect on this macropore matrix interaction than the soil physical properties of the matrix. Although the amount of macropores and their effectiveness are clearly related to the earthworm distribution, the variation in infiltration from macropores to soil matrix should be further studied.},
  language  = {en}
}
@article{KlausZeheElsneretal.2014,
  author    = {Klaus, Julian and Zehe, Erwin and Elsner, Martin and Palm, Juliane and Schneider, Dorothee and Schroeder, Boris and Steinbeiss, Sibylle and van Schaik, Loes and West, Stephanie},
  title     = {Controls of event-based pesticide leaching in natural soils: A systematic study based on replicated field scale irrigation experiments},
  series = {Journal of hydrology},
  volume    = {512},
  journal   = {Journal of hydrology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0022-1694},
  doi       = {10.1016/j.jhydrol.2014.03.020},
  pages     = {528 -- 539},
  year      = {2014},
  abstract  = {Tile drains strongly influence the water cycle in agricultural catchment in terms of water quantity and quality. The connectivity of preferential flow to tile drains can create shortcuts for rapid transport of solutes into surface waters. The leaching of pesticides can be linked to a set of main factors including, rainfall characteristics, soil moisture, chemical properties of the pesticides, soil properties, and preferential flow paths. The connectivity of the macropore system to the tile drain is crucial for pesticide leaching. Concurring influences of the main factors, threshold responses and the role of flow paths are still poorly understood. The objective of this study is to investigate these influences by a replica series of three irrigation experiments on a tile drain field site using natural and artificial tracers together with applied pesticides. We found a clear threshold behavior in the initialization of pesticide transport that was different between the replica experiments. Pre-event soil water contributed significantly to the tile drain flow, and creates a flow path for stored pesticides from the soil matrix to the tile drain. This threshold is controlled by antecedent soil moisture and precipitation characteristics, and the interaction between the soil matrix and preferential flow system. Fast transport of pesticides without retardation and the remobilization could be attributed to this threshold and the interaction between the soil matrix and the preferential flow system. Thus, understanding of the detailed preferential flow processes clearly enhances the understanding of pesticide leaching on event and long term scale, and can further improve risk assessment and modeling approaches. (C) 2014 Elsevier B.V. All rights reserved.},
  language  = {en}
}