Most soils develop distinct soil architecture during pedogenesis and soil organic carbon (SOC) is sequestered within a hierarchical system of mineral-organic associations and aggregates. Permafrost soils store large amounts of carbon due to their permanently frozen subsoil and a lack of oxygen in the active layer, but they lack complex soil structure. With permafrost thaw more oxidative conditions and increasing soil temperature presumably enhance the build-up of more complex units of soil architecture and may counterbalance, at least partly, SOC mineralization. We aim to explore the development of mineral-organic associations and aggregates under different permafrost impact with respect to SOC stabilization. This information will be linked to environmental control factors relevant for SOC turnover at the pedon and stand scale to bridge processes occurring at the aggregate scale to larger spatial dimensions. We will combine in situ spectroscopic techniques with fractionation approaches and identify mechanisms relevant for SOC turnover at different scales by multivariate statistics and variogram analyses. From this we expect a deeper knowledge about soil architecture formation in the transition of permafrost soils to terrestrial soils and a scale-spanning mechanistic understanding of SOC cycling in permafrost regions.
The biogeochemical interface (BGI) in this project is defined as the organo-mineral surface of soil particles colonized by microorganisms. In the preceding project it was demonstrated that the different soil particle size fractions were associated with specifically structured microbial communities, a characteristic amount of soil organic carbon, and a specific capacity for adsorption of the organic chemicals phenol and 2,4-dichlorophenol, respectively. While the diversity of the microbial community was responsive to fertilization-determined additional organic soil carbon in the larger particle size fractions, it was unaffected in clay. Stable isotope probing with 13C-labelled phenol and 2,4-dichlorophenol revealed that the soil organic carbon in the BGIs also affected the diversity of microorganisms involved in the degradation of these chemicals. All these results are yet only based on studying one soil with three organic carbon variants (Bad Lauchstädt) and only two organic compounds. The objective of this 2nd phase project is to apply the innovative technology developed in the 1st phase for studying the BGI processes with soil organic carbon variants from another soil (Ultuna, SPP 1315 site) and with the chiralic anilide Fungicide metalaxyl as an additional compound. This 2nd phase SPP 1315 project will also, in a collaborative effort with two other SPP 1315 partners, investigate (1) the importance of BGIs for the entantio-selective degradation of metalaxyl and (2) the role of soil microorganisms in the formation of bound residues, respectively. Furthermore, the project will utilize stable isotope probing and next-generation DNA sequencing to link the structural and functional diversity of the microbial communities responsible for metabolism of organic chemicals in the different BGIs determined by particle size fractions and soil organic carbon variants.
This series refers to datasets related to the presence of people; livelihoods; species or ecosystems; environmental functions, services, and resources; infrastructure; or economic, social, or cultural assets in places and settings that could be adversely affected by climate hazards, including flooding, wildfires and urban heat island effects.
The datasets are part of the European Climate Adaptation Platform (Climate-ADAPT) accessible here: https://climate-adapt.eea.europa.eu/
Organotin and especially butyltin compounds are used for a variety of applications, e.g. as biocides, stabilizers, catalysts and intermediates in chemical syntheses. Tributyltin (TBT) compounds exhibit the greatest toxicity of all organotins and have even been characterized as one of the most toxic groups of xenobiotics ever produced and deliberately introduced into the environment. TBT is not only used as an active biocidal compound in antifouling paints, which are designed to prevent marine and freshwater biota from settlement on ship hulls, harbour and offshore installations, but also as a biocide in wood preservatives, textiles, dispersion paints and agricultural pesticides. Additionally, it occurs as a by-product of mono- (MBT) and dibutyltin (DBT) compounds, which are used as UV stabilizer in many plastics and for other applications. Triphenyltin (TPT) compounds are also used as the active biocide in antifouling paints outside Europe and furthermore as an agricultural fungicide since the early 1960s to combat a range of fungal diseases in various crops, particularly potato blight, leaf spot and powdery mildew on sugar beet, peanuts and celery, other fungi on hop, brown rust on beans, grey moulds on onions, rice blast and coffee leaf rust. Although the use of TBT and TPT was regulated in many countries world-wide from restrictions for certain applications to a total ban, these compounds are still present in the environment. In the early 1970s the impact of TBT on nontarget organisms became apparent. Among the broad variety of malformations caused by TBT in aquatic animals, molluscs have been found to be an extremely sensitive group of invertebrates and no other pathological condition produced by TBT at relative low concentrations rivals that of the imposex phenomenon in prosobranch gastropods speaking in terms of sensitivity. TBT induces imposex in marine prosobranchs at concentrations as low as 0,5 ng TBT-Sn/L. Since 1993, for the littorinid snail Littorina littorea a second virilisation phenomenon, termed intersex, is known. In female specimens affected by intersex the pallial oviduct is transformed of towards a male morphology with a final supplanting of female organs by the corresponding male formations. Imposex and intersex are morphological alterations caused by a chronic exposure to ultra-trace concentrations of TBT. A biological effect monitoring offers the possibility to determine the degree of contamination with organotin compounds in the aquatic environment and especially in coastal waters without using any expensive analytical methods. Furthermore, the biological effect monitoring allows an assessment of the existing TBT pollution on the basis of biological effects. Such results are normally more relevant for the ecosystem than pure analytical data. usw.