Martin Herbert Schroth

Last Name

Schroth

First Name

Martin Herbert

ORCID

0000-0002-0137-929X

Organisational unit

03850 - McNeill, Kristopher / McNeill, Kristopher

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Publications1 - 10 of 78

Quantity and distribution of methane entrapped in sediments of calcareous, Alpine glacier forefields
Zhu, Biqing; Kübler, Manuel; Ridoli, Melanie; et al. (2020)
Biogeosciences
Aside from many well-known sources, the greenhouse gas methane (CH4) was recently discovered entrapped in the sediments of Swiss Alpine glacier forefields derived from calcareous bedrock. A first study performed in one glacial catchment indicated that CH4 was ubiquitous in sediments and rocks and was largely of thermogenic origin. Here, we present the results of a follow-up study that aimed at (1) determining the occurrence and origin of sediment-entrapped CH4 in other calcareous glacier forefields across Switzerland and (2) providing an inventory of this sediment-entrapped CH4, i.e., determining the contents and total mass of CH4 present, and its spatial distribution within and between five different Swiss glacier forefields situated on calcareous formations of the Helvetic nappes in the Central Alps. Sediment and bedrock samples were collected at high spatial resolution from the forefields of Im Griess, Griessfirn, Griessen, Wildstrubel, and Tsanfleuron glaciers, representing different geographic and geologic regions of the Helvetic nappes. We performed geochemical analyses on gas extracted from sediments and rocks, including the determination of CH4 contents, stable carbon-isotope analyses (δ13CCH4), and the determination of gas-wetness ratios (ratio of CH4 to ethane and propane contents). To estimate the total mass of CH4 entrapped in glacier-forefield sediments, the total volume of sediment was determined based on the measured forefield area and either literature values of mean sediment thickness or direct depth measurements using electrical resistivity tomography. Methane was found in all sediments (0.08–73.81 µg CH4 g−1 dry weight) and most rocks (0.06–108.58 µg CH4 g−1) collected from the five glacier forefields, confirming that entrapped CH4 is ubiquitous in these calcareous formations. Geochemical analyses further confirmed a thermogenic origin of the entrapped CH4 (average δ13CCH4 of sediment of −28.23 (± 3.42) ‰; average gas-wetness ratio of 75.2 (± 48.4)). Whereas sediment-entrapped CH4 contents varied moderately within individual forefields, we noted a large, significant difference in the CH4 content and total CH4 mass (range of 200–3881 t CH4) between glacier forefields at the regional scale. The lithology and tectonic setting within the Helvetic nappes appeared to be dominant factors determining rock and sediment CH4 contents. Overall, a substantial quantity of CH4 was found to be entrapped in Swiss calcareous glacier forefields. Its potential release and subsequent fate in this environment is the subject of ongoing studies.
Sulfate-reducing bacterial community response to carbon source amendments in contaminated aquifer microcosms
Kleikemper, Jutta; Pelz, Oliver; Schroth, Martin Herbert; et al. (2002)
FEMS Microbiology Ecology
Redox Properties of Peat Particulate Organic Matter From Five Ombrotrophic Bogs in Central Sweden
Obradović, Nikola; Schmitz, Rob A.; Arn, Silvan; et al. (2025)
Journal of Geophysical Research: Biogeosciences
Peat particulate organic matter (POM) is increasingly recognized as an important terminal electron acceptor (TEA) for anaerobic microbial respiration in anoxic peat soils. The goal of this work was to quantify the electron-accepting capacity (EAC) of POM that is accessible to microbes in these soils under in situ conditions. To this end, we collected 28 reduced POM samples from the anoxic subsurface along transects in Sphagnum-dominated ombrotrophic bogs in central Sweden. These POM samples had similar physicochemical properties and compositions within and across peatlands, as inferred from elemental analysis, infrared spectroscopy, and solid-state 13C nuclear magnetic resonance spectroscopy. The microbially accessible EAC of these POM samples were determined by quantifying the increases in the total EACs and concomitant decreases in electron-donating capacities when reacting the field-collected reduced POM with dissolved oxygen (DO). These analyses suggested that between 90 and 390 μmol electrons per gram of POM carbon are microbially transferrable to POM. The reaction of POM with DO was found to also result in equimolar conversion of electron-donating to electron-accepting moieties in POM, demonstrating fully reversible electron transfer to and from POM and, therefore, that POM is a sustainable TEA in temporarily anoxic peat soils. A comparison of the microbially accessible EAC of POM to that of pore-water inorganic TEA species and reported EACs and measured concentrations of peat-dissolved organic matter revealed that POM is the major TEA in the studied bogs.
Assessment of microbial methane oxidation above a petroleum-contaminated aquifer using a combination of in-situ techniques
Urmann, Karina; Schroth, Martin Herbert; Noll, Matthias; et al. (2008)
Journal of Geophysical Research: Biogeosciences
Emissions of the greenhouse gas CH4, which is often produced in contaminated aquifers, are reduced or eliminated by microbial CH4 oxidation in the overlying vadose zone. The aim of this field study was to estimate kinetic parameters and isotope fractionation factors for CH4 oxidation in situ in the vadose zone above a methanogenic aquifer in Studen, Switzerland, and to characterize the involved methanotrophic communities. To quantify kinetic parameters, several field tests, so-called gas push-pull tests (GPPTs), with CH4 injection concentrations ranging from 17 to 80 mL L−1 were performed. An apparent Vmax of 0.70 ± 0.15 mmol CH4 (L soil air)−1 h−1 and an apparent Km of 0.28 ± 0.09 mmol CH4 (L soil air)−1 was estimated for CH4 oxidation at 2.7 m depth, close to the groundwater table. At 1.1 m depth, Km (0.13 ± 0.02 mmol CH4 (L soil air)−1) was in a similar range, but Vmax (0.076 ± 0.006 mmol CH4 (L soil air)−1 h−1) was an order of magnitude lower. At 2.7 m, apparent first-order rate constants determined from a CH4 gas profile (1.9 h−1) and from a single GPPT (2.0 ± 0.03 h−1) were in good agreement. Above the groundwater table, a Vmax much higher than the in situ CH4 oxidation rate prior to GPPTs indicated a high buffer capacity for CH4. At both depths, known methanotrophic species affiliated with Methylosarcina and Methylocystis were detected by cloning and sequencing. Apparent stable carbon isotope fractionation factors α for CH4 oxidation determined during GPPTs ranged from 1.006 to 1.032. Variability was likely due to differences in methanotrophic activity and CH4 availability leading to different degrees of mass transfer limitation. This complicates the use of stable isotopes as an independent quantification method.
Development and Evaluation of Micro Push–Pull Tests to Investigate Micro-Scale Processes in Porous Media
Knecht, Kajsa; Schroth, Martin Herbert; Schulin, R.; et al. (2011)
Environmental Science & Technology
Occurrence and Origin of Methane Entrapped in Sediments and Rocks of a Calcareous, Alpine Glacial Catchment
Zhu, Biqing; Henneberger, Ruth; Weissert, Helmut; et al. (2018)
Journal of Geophysical Research: Biogeosciences
Modeling of a microbial growth experiment with bioclogging in a two dimensional saturated porous media flow field
Thullner, Martin; Schroth, Martin Herbert; Zeyer, Josef; et al. (2004)
Journal of Contaminant Hydrology
A Micro Push-Pull Test for Investigating Rhizosphere Processes
Knecht, Kajsa; Schroth, Martin Herbert; Schulin, R.; et al. (2011)
Electron-Donating Phenolic and Electron-Accepting Quinone Moieties in Peat Dissolved Organic Matter: Quantities and Redox Transformations in the Context of Peat Biogeochemistry
Walpen, Nicolas; Getzinger, Gordon J.; Schroth, Martin Herbert; et al. (2018)
Environmental Science & Technology
Effects of eutrophication on sedimentary organic carbon cycling in five temperate lakes
Fiskal, Annika; Deng, Longhui; Michel, Anja; et al. (2019)
Biogeosciences
Even though human-induced eutrophication has severely impacted temperate lake ecosystems over the last centuries, the effects on total organic carbon (TOC) burial and mineralization are not well understood. We study these effects based on sedimentary records from the last 180 years in five Swiss lakes that differ in trophic state. We compare changes in TOC content and modeled TOC accumulation rates through time to historical data on algae blooms, water column anoxia, wastewater treatment, artificial lake ventilation, and water column phosphorus (P) concentrations. We furthermore investigate the effects of eutrophication on rates of microbial TOC mineralization and vertical distributions of microbial respiration reactions in sediments. Our results indicate that the history of eutrophication is well recorded in the sedimentary record. Overall, eutrophic lakes have higher TOC burial and accumulation rates, and subsurface peaks in TOC coincide with past periods of elevated P concentrations in lake water. Sediments of eutrophic lakes, moreover, have higher rates of total respiration and higher contributions of methanogenesis to total respiration. However, we found strong overlaps in the distributions of respiration reactions involving different electron acceptors in all lakes regardless of lake trophic state. Moreover, even though water column P concentrations have been reduced by ∼ 50 %–90 % since the period of peak eutrophication in the 1970s, TOC burial and accumulation rates have only decreased significantly, by ∼ 20 % and 25 %, in two of the five lakes. Hereby there is no clear relationship between the magnitude of the P concentration decrease and the change in TOC burial and accumulation rate. Instead, data from one eutrophic lake suggest that artificial ventilation, which has been used to prevent water column anoxia in this lake for 35 years, may help sustain high rates of TOC burial and accumulation in sediments despite water column P concentrations being strongly reduced. Our study provides novel insights into the influence of human activities in lakes and lake watersheds on lake sediments as carbon sinks and habitats for diverse microbial respiration processes.

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Martin Herbert Schroth

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