Soil organic matter is very important for many soil functions. How long carbon remains in the soil is a key factor, but until now this has been little understood. Samuel Abiven and his team would like to raise the understanding of the dynamics of soil carbon. They are particularly concerned with the reaction of the soil organic matter to climate change and to changes in land use. The soil organic matter consists of a mixture of organic molecules that come from plant residues, as well as micro-organisms that decompose these residues in the soil and transform them. The soil organic matter contains a significant amount of the carbon, which, in terms of quantity comes globally to almost three times more than the amount contained in the atmosphere in the form of carbon dioxide and methane. In the soil, the carbon is however turning over much more slowly than in the atmosphere or with plant biomass. Soils can therefore be a sink for carbon, but also serve as a source, if conditions change and decomposition is accelerated. Climate change, for instance, can modify micro-organism activity as well as the structure of the soil organic matter. Changes in land use can change the physico-chemical properties, as well as the kind of litter material that penetrates the soil. The investigations will be coordinated with the research team of Frank Hagedorn (WSL) and Tim Eglinton (ETH Zurich). It is currently difficult to characterise the development of soil organic matter underlying these changes. It depends to a large part on the vulnerability of the organic soil matter to these changes. The project examines the vulnerability of soils, which - just like forest soils - possess a very high level of organic matter and therefore have a higher risk of losing soil matter as a consequence of climate and land use changes. The team, in so doing, is searching for possibilities to ascertain the vulnerability of the soils by examining their properties. It is be possible in this way to identify the most endangered soils and take suitable protective measures.
This dataset provides molecular formulae with their normalized mass peak intensities obtained from ultrahigh resolution mass spectrometric analysis of organic matter (OM) from glacier purple ice- and red snow-algae dominated samples collected upwind of the DEEP PURPLE ice camp (deeppurple-ercsyg.eu) on the surface of the Greenland Ice Sheet. The samples are represented by the initial OM from glacier ice- (T0_Ice) and snow-algae (T0_Snow) dominated habitats and the up to 24 days (T3-T24) in situ incubated samples under dark (D) and light (L) conditions. OM samples, include dissolved organic matter (DOM) and particulate organic matter (POM), the latter extracted with hot water (HW) and sodium hydroxide (Na) to represent water-soluble and particle-associated OM, respectively (see methods). Molecular analyses were performed on a Solarix Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS) equipped with a 15 Tesla superconducting magnet (Bruker Daltonic) using an electrospray ionization source (ESI, Bruker Apollo II) in negative ion mode on DOM samples and POM extracts previously solid phase extracted (SPE, Dittmar et al., 2008). Molecular formula calculation for all samples was performed using the software ICBM-OCEAN (Merder et al., 2020) and include the following combination of elements: C0-100, O0-50, H0-200, N0-4, S0-2 and P0-1 (the full description of the data and methods is provided in the data description file). Because DOM and POM samples were analyzed in duplicates in the mass spectrometer, a compound was considered to be present if it appeared in both duplicate measurements. The mean normalized intensity of duplicate measurements is presented here and was further used for statistical analysis in Rossel et al., to be submitted. This dataset contains 8827 molecular formulae with their normalized peaks intensities.
This dataset provides the dissolved organic carbon (DOC) concentrations of the organic matter (OM) obtained from glacier purple ice- and red snow-algae dominated samples collected upwind of the DEEP PURPLE ice camp (deeppurple-ercsyg.eu) on the surface of the Greenland Ice Sheet. The samples are represented by the initial OM from glacier ice- (T0_Ice) and snow-algae (T0_Snow) dominated habitats and the up to 24 days (T3-T24) in situ incubated samples under dark (D) and light (L) conditions. OM samples, include dissolved organic matter (DOM) and particulate organic matter (POM), the latter extracted with hot water (HW) and sodium hydroxide (Na) to represent water-soluble and particle-associated OM, respectively (see methods). Dissolved organic carbon concentrations were determined as non-purgeable organic carbon obtained from replicate measurements of DOM and POM extracts analyzed in a Shimadzu high-sensitivity TOC-V analyzer. The concentrations in this dataset are part of the supplementary material in Rossel et al. (2025).