@article{PuppeWannerSommer2018,
  author    = {Puppe, Daniel and Wanner, Manfred and Sommer, Michael},
  title     = {Data on euglyphid testate amoeba densities, corresponding protozoic silicon pools, and selected soil parameters of initial and forested biogeosystems},
  series = {Data in brief},
  volume    = {21},
  journal   = {Data in brief},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2352-3409},
  doi       = {10.1016/j.dib.2018.10.164},
  pages     = {1697 -- 1703},
  year      = {2018},
  abstract  = {The dataset in the present article provides information on protozoic silicon (Si) pools represented by euglyphid testate amoebae (TA) in soils of initial and forested biogeosystems. Protozoic Si pools were calculated from densities of euglyphid TA shells and corresponding Si contents. The article also includes data on potential annual biosilicification rates of euglyphid TA at the examined sites. Furthermore, data on selected soil parameters (e.g., readily-available Si, soil pH) and site characteristics (e.g., soil groups, climate data) can be found. The data might be interesting for researchers focusing on biological processes in Si cycling in general and euglyphid TA and corresponding protozoic Si pools in particular.},
  language  = {en}
}
@article{WannerSeidlLampaHoehnetal.2016,
  author    = {Wanner, Manfred and Seidl-Lampa, Barbara and H{\"o}hn, Axel and Puppe, Daniel and Meisterfeld, Ralf and Sommer, Michael},
  title     = {Culture growth of testate amoebae under different silicon concentrations},
  series = {European journal of protistology},
  volume    = {56},
  journal   = {European journal of protistology},
  publisher = {Royal Society of Chemistry},
  address   = {Jena},
  organization    = {Veritas Collaboration},
  issn      = {0932-4739},
  doi       = {10.1016/j.ejop.2016.08.008},
  pages     = {171 -- 179},
  year      = {2016},
  abstract  = {Testate amoebae with self-secreted siliceous shell platelets ("idiosomes") play an important role in terrestrial silicon (Si) cycles. In this context, Si-dependent culture growth dynamics of idiosomic testate amoebae are of interest. Clonal cultures of idiosomic testate amoebae were analyzed under three different Si concentrations: low (50 mu mol L-1), moderate/site-specific (150 mu mol L-1) and high Si supply (500 mu mol L-1). Food (Saccharomyces cerevisiae) was provided in surplus. (i) Shell size of four different clones of idiosomic testate amoebae either decreased (Trinema galeata, Euglypha filifera cf.), increased (E. rotunda cf.), or did not change (E. rotunda) under the lowest Si concentration (50 mu mol Si L-1). (ii) Culture growth of idiosomic Euglypha rotunda was dependent on Si concentration. The more Si available in the culture medium, the earlier the entry into exponential growth phase. (iii) Culture growth of idiosomic Euglypha rotunda was dependent on origin of inoculum. Amoebae previously cultured under a moderate Si concentration revealed highest sustainability in consecutive cultures. Amoebae derived from cultures with high Si concentrations showed rapid culture growth which finished early in consecutive cultures. (iv) Si (diluted in the culture medium) was absorbed by amoebae and fixed in the amoeba shells resulting in decreased Si concentrations. (C) 2016 Elsevier GmbH. All rights reserved.},
  language  = {en}
}
@article{PuppeEhrmannKaczoreketal.2015,
  author    = {Puppe, Daniel and Ehrmann, Otto and Kaczorek, Danuta and Wanner, Manfred and Sommer, Michael},
  title     = {The protozoic Si pool in temperate forest ecosystems - Quantification, abiotic controls and interactions with earthworms},
  series = {Geoderma : an international journal of soil science},
  volume    = {243},
  journal   = {Geoderma : an international journal of soil science},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0016-7061},
  doi       = {10.1016/j.geoderma.2014.12.018},
  pages     = {196 -- 204},
  year      = {2015},
  abstract  = {Biogenic silicon (BSI) pools influence Si cycling in terrestrial ecosystems. As research has been focused mainly on phytogenic BSi pools until now, there is only little information available on quantities of other BSi pools. There are no systematic studies on protozoic Si pools - here represented by idiosomic testate amoebae (TA) - and abiotic and biotic influences in temperate forest ecosystems. We selected ten old forests along a strong gradient in soil forming factors (especially parent material and climate), soil properties and humus forms. We quantified idiosomic Si pools, corresponding annual biosilicification, plant-available and amorphous Si fractions of topsoil horizons. Furthermore, we analyzed the potential influences of abiotic factors (e.g. soil pH) and earthworms on idiosomic Si pools. While idiosomic Si pools were relatively small (up to 5 kg Si ha(-1)), annual biosilicification rates of living TA (17-80 kg Si ha(-1)) were comparable to or even exceeded reported data of annual Si uptake by trees. Soil pH exerted a strong, non-linear control on plant-available Si. Surprisingly, no relationship between Si supply and idiosomic Si pools could be found (no Si limitation). Instead, idiosomic Si pools showed a strong, negative relationship to earthworm biomasses, which corresponded to humus forms. We concluded that earthworms control idiosomic Si pools in forest soils by direct (feeding, competition) and/or indirect mechanisms (e.g. change of habitat structure). Earthworms themselves were strongly influenced by soil pH: Below a threshold of pH 3.8 no endogeic or anecic earthworms existed. As soil pH is a result of weathering and acidification idiosomic Si pools are indirectly, but ultimately controlled by soil forming factors, mainly parent material and climate. (C) 2014 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{PuppeKaczorekWanneretal.2014,
  author    = {Puppe, Daniel and Kaczorek, Danuta and Wanner, Manfred and Sommer, Michael},
  title     = {Dynamics and drivers of the protozoic Si pool along a 10-year chronosequence of initial ecosystem states},
  series = {Ecological engineering : the journal of ecotechnology},
  volume    = {70},
  journal   = {Ecological engineering : the journal of ecotechnology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0925-8574},
  doi       = {10.1016/j.ecoleng.2014.06.011},
  pages     = {477 -- 482},
  year      = {2014},
  abstract  = {The size and dynamics of biogenic silicon (BSi) pools influence silicon (Si) fluxes from terrestrial to aquatic ecosystems. The research focus up to now was on the role of plants in Si cycling. In recent studies on old forests annual biosilicification rates of idiosomic testate amoebae (i.e. TA producing self-secreted silica shells) were shown to be of the order of Si uptake by trees. However, no comparable data exist for initial ecosystems. We analyzed the protozoic BSi pool (idiosomic TA), corresponding annual biosilicification rates and readily available and amorphous Si fractions along a 10-year chronosequence in a post-mining landscape in Brandenburg, Germany. Idiosomic Si pools ranged from 3 to 680 g Si ha(-1) and were about 3-4 times higher at vegetated compared to uncovered spots. They increased significantly with age and were related to temporal development of soil chemical properties. The calculation of annual biosilicification resulted in maxima between 2 and 16 kg Si ha(-1) with rates always higher at vegetated spots. Our results showed that the BSi pool of idiosomic TA is built up rapidly during the initial phases of ecosystem development and is strongly linked to plant growth. Furthermore, our findings highlight the importance of TA for Si cycling in young artificial ecosystems. (C) 2014 Elsevier B.V. All rights reserved.},
  language  = {en}
}