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Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 14, issue 22
Biogeosciences, 14, 5239-5252, 2017
https://doi.org/10.5194/bg-14-5239-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 14, 5239-5252, 2017
https://doi.org/10.5194/bg-14-5239-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 23 Nov 2017

Research article | 23 Nov 2017

How big is the influence of biogenic silicon pools on short-term changes in water-soluble silicon in soils? Implications from a study of a 10-year-old soil–plant system

Daniel Puppe1, Axel Höhn1, Danuta Kaczorek1,2, Manfred Wanner3, Marc Wehrhan1, and Michael Sommer1,4 Daniel Puppe et al.
  • 1Leibniz Centre for Agricultural Landscape Research (ZALF) e.V., Institute of Soil Landscape Research, 15374 Müncheberg, Germany
  • 2Department of Soil Environment Sciences, Warsaw University of Life Science (SGGW), Nowoursynowska 159, 02-776 Warsaw, Poland
  • 3Brandenburg University of Technology Cottbus-Senftenberg, Department Ecology, 03013 Cottbus, Germany
  • 4Institute of Earth and Environmental Sciences, University of Potsdam, 14476 Potsdam, Germany

Abstract. The significance of biogenic silicon (BSi) pools as a key factor for the control of Si fluxes from terrestrial to aquatic ecosystems has been recognized for decades. However, while most research has been focused on phytogenic Si pools, knowledge of other BSi pools is still limited. We hypothesized that different BSi pools influence short-term changes in the water-soluble Si fraction in soils to different extents. To test our hypothesis we took plant (Calamagrostis epigejos, Phragmites australis) and soil samples in an artificial catchment in a post-mining landscape in the state of Brandenburg, Germany. We quantified phytogenic (phytoliths), protistic (diatom frustules and testate amoeba shells) and zoogenic (sponge spicules) Si pools as well as Tiron-extractable and water-soluble Si fractions in soils at the beginning (t0) and after 10 years (t10) of ecosystem development. As expected the results of Tiron extraction showed that there are no consistent changes in the amorphous Si pool at Chicken Creek (Hühnerwasser) as early as after 10 years. In contrast to t0 we found increased water-soluble Si and BSi pools at t10; thus we concluded that BSi pools are the main driver of short-term changes in water-soluble Si. However, because total BSi represents only small proportions of water-soluble Si at t0 (<2%) and t10 (2.8–4.3%) we further concluded that smaller (<5µm) and/or fragile phytogenic Si structures have the biggest impact on short-term changes in water-soluble Si. In this context, extracted phytoliths (>5µm) only amounted to about 16% of total Si contents of plant materials of C. epigejos and P. australis at t10; thus about 84% of small-scale and/or fragile phytogenic Si is not quantified by the used phytolith extraction method. Analyses of small-scale and fragile phytogenic Si structures are urgently needed in future work as they seem to represent the biggest and most reactive Si pool in soils. Thus they are the most important drivers of Si cycling in terrestrial biogeosystems.

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We quantified different biogenic Si pools in soils of a developing ecosystem and analyzed their influence on short-term changes of the water soluble Si fraction. From our results we concluded small (< 5 µm) and/or fragile phytogenic Si structures to have the biggest impact on short-term changes of water soluble Si. Analyses of these phytogenic Si structures are urgently needed in future as they seem to represent the most important driver of Si cycling in terrestrial biogeosystems in general.
We quantified different biogenic Si pools in soils of a developing ecosystem and analyzed their...
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