TY  - JOUR
A1  - Puppe, Daniel
A1  - Höhn, Axel
A1  - Kaczorek, Danuta
A1  - Wanner, Manfred
A1  - Sommer, Michael
T1  - As time goes by-Spatiotemporal changes of biogenic Si pools in initial soils of an artificial catchment in NE Germany
JF  - Applied soil ecology : a section of agriculture, ecosystems & environment
KW  - Biogenic silica
KW  - Diatom frustule
KW  - Testate amoeba shell
KW  - Sponge spicule
KW  - Initial ecosystem
Y1  - 2016
U6  - https://doi.org/10.1016/j.apsoil.2016.01.020
SN  - 0929-1393
SN  - 1873-0272
VL  - 105
SP  - 9
EP  - 16
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Puppe, Daniel
A1  - Ehrmann, Otto
A1  - Kaczorek, Danuta
A1  - Wanner, Manfred
A1  - Sommer, Michael
T1  - The protozoic Si pool in temperate forest ecosystems - Quantification, abiotic controls and interactions with earthworms
JF  - Geoderma : an international journal of soil science
N2  - 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.
KW  - Biogenic silica
KW  - Testate amoebae
KW  - Biosilicification
KW  - Terrestrial Si cycle
KW  - Si fractions
KW  - Humus forms
Y1  - 2015
U6  - https://doi.org/10.1016/j.geoderma.2014.12.018
SN  - 0016-7061
SN  - 1872-6259
VL  - 243
SP  - 196
EP  - 204
PB  - Elsevier
CY  - Amsterdam
ER  -