Article

Biogeochemistry

, Volume 101, Issue 1, pp 165-176

Initial pedogenesis in a topsoil crust 3 years after construction of an artificial catchment in Brandenburg, NE Germany

  • Thomas FischerAffiliated withCentral Analytical Laboratory, Faculty of Environmental Sciences and Process Engineering, Brandenburg University of Technology at Cottbus Email author 
  • , Maik VesteAffiliated withResearch Center Landscape Development and Mining Landscapes, Brandenburg University of Technology at Cottbus
  • , Wolfgang SchaafAffiliated withChair of Soil Protection and Recultivation, Faculty of Environmental Sciences and Process Engineering, Brandenburg University of Technology at Cottbus
  • , Alexander DümigAffiliated withLehrstuhl für Bodenkunde, Department für Ökologie und Ökosystemmanagement, Technische Universität München
  • , Ingrid Kögel-KnabnerAffiliated withLehrstuhl für Bodenkunde, Department für Ökologie und Ökosystemmanagement, Technische Universität München
  • , Wolfgang WieheAffiliated withCentral Analytical Laboratory, Faculty of Environmental Sciences and Process Engineering, Brandenburg University of Technology at Cottbus
  • , Oliver BensAffiliated withGFZ German Research Centre for Geosciences
  • , Reinhard F. HüttlAffiliated withChair of Soil Protection and Recultivation, Faculty of Environmental Sciences and Process Engineering, Brandenburg University of Technology at CottbusGFZ German Research Centre for Geosciences

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Cyanobacteria and green algae present in biological soil crusts are able to colonize mineral substrates even under extreme environmental conditions. As pioneer organisms, they play a key role during the first phases of habitat colonization. A characteristic crust was sampled 3 years after installation of the artificial water catchment “Chicken creek”, thus representing an early successional stage of ecosystem development. Mean annual rainfall and temperature were 559 mm and 9.3°C, respectively. We combined scanning electron microscopy (SEM/EDX) and infrared (FTIR) microscopy to study the contact zone of algal and cyanobacterial mucilage with soil minerals in an undisturbed biological soil crust and in the subjacent sandy substrate. The crust was characterized by an approximately 50 μm thick surface layer, where microorganisms resided and where mineral deposition was trapped, and by an approximately 2.5 mm thick lower crust where mineral particles were stabilized by organo-mineral structures. SEM/EDX microscopy was used to determine the spatial distribution of elements, organic compounds and minerals were identified using FTIR microscopy and X-ray diffraction (XRD). The concentration of organic carbon in the crust was about twice as much as in the parent material. Depletion of Fe, Al and Mn in the lower crust and in the subjacent 5 mm compared to the geological substrate was observed. This could be interpreted as the initial phase of podzolization. Existence of bridging structures between mineral particles of the lower crust, containing phyllosilicates, Fe compounds and organic matter (OM), may indicate the formation of organo-mineral associations. pH decreased from 8.1 in the original substrate to 5.1 on the crust surface 3 years after construction, pointing to rapid weathering of carbonates. Weathering of silicates could not be detected.

Keywords

Biological soil crust Initial ecosystem Scanning electron microscopy FTIR microscopy