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Methane ebullition, sedimentation rates, organic matter quality and environmental parameters at small and shallow temperate Lake Windsborn, Germany in 2017 and 2018

To determine spatiotemporal variability of methane (CH4) ebullition and its drivers, we measured CH4 ebullition rates, sedimentation rates and characteristics of the sedimented material, sediment chemical and physical characteristics and environmental parameters at Lake Windsborn in 2017 and 2018. Measurements of CH4 ebullition were conducted bi-weekly from May to October 2017 and April to November 2018. Sedimentation rates were measured in 2018 in four-week intervals. Characteristics of the sedimented material were measured in 2017 and 2018. Sediment characteristics were measured in November 2017, spring 2018 and August 2019. Meterological parameters (temperature and air pressure) were constantly measured from a floating platform in the lake center.

TropSOC Database

We provide version 1.0 of an open access database created as part of the project “Tropical soil organic carbon dynamics along erosional disturbance gradients in relation to variability in soil geochemistry and land use” (TropSOC). TropSOC v1.0 contains spatial and temporal explicit data on soil, vegetation, environmental properties and land management collected from 136 pristine tropical forest and cropland plots between 2017 and 2020 as part of several monitoring and sampling campaigns in the Eastern Congo Basin and the East African Rift Valley System. The results of several laboratory experiments focussing on soil microbial activity, C cycling and C stabilization in soils complement the dataset to deliver one of the first landscape scale datasets to study the linkages and feedbacks between geology, geomorphology and pedogensis as controls on biogeochemical cycles in a variety of natural and managed systems in the African Tropics. Sampling procedures are described in each metadata description .pdf file accompanying a specific .csv file that represents a methodologically distinct subset of the database. A general overview of field sampling procedures and design is given in Doetterl et al., (2021, ESSD in review) which describes the dataset as a whole. Analytical procedures are described in each metadata description .pdf file accompanying a specific .csv file that represents a methodologically distinct subset of the database. Data processing and quality control are described in each metadata description .pdf file accompanying a specific .csv file that represents a methodologically distinct subset of the database.

Arctic Greening Database

The Arctic Greening Database v0.1 is an open access database created as part of the ETH+ project "Unraveling biogeochemical, microbial and vegetation feedbacks driving soil development and Arctic greening under a warming climate". The database contains data on soil, vegetation, microbial, and environmental properties from 14 active-layer tundra sites sampled in 2022 and 2023 on Svalbard. The spatially-explicit field observations, field and laboratory measurements provides an interdisciplinary collection of data from a remote and data-poor region to study linkages between vegetation, microbiome and pedogenesis in the context of Arctic Greening. The database is structured hierarchically with four connected levels: site, plot, sample, and species. At the site level, aggregated data are provided (e.g. GHG fluxes). This is followed by plot-level data (e.g. plant functional type cover) that connects to sample-level data (soil organic matter content) and species-level data. Tables at the same level are connected via one-to-one relationships, from a broader to finer level one-to-many relationships are in place. Sampling and measurement procedures are described in Section 2 of the database description. The metadata file accompanying a specific .csv file provides further information on data creation, sample processing and units. The current version of the dataset consists of a reduced set of tables that will be updated soon with more curated data from Svalbard and Northern Norway (Finnmark). A more extensive overview of the data will be published as a data paper in the future.

Alpine ecosystems in a changing climate: experimental CO2 enrichment and warming

Within the next decades, a two-fold increase in CO2 concentrations and a rise in temperatures by 1.4 to 5.8 C can be expected (IPCC 2001). Temperature changes in the past decades have been more pronounced in alpine and high-latitude ecosystems than in most other regions of the world (IPCC 2001). Alpine ecosystems are particularly sensitive to environmental changes because they represent a boundary ecosystem that is subjected to extreme climatic conditions. Since temperature and CO2 are key factors that regulate many ecosystem processes, the changing climate will have large effects on vegetation and soils. In this proposal, we intend to analyze effects of manipulated temperature and CO2 in alpine ecosystems at treeline. Our major aim is to study potential feedbacks between climate change, plant growth and ecosystem processes. Although the European Alps are certainly the most studied of all high mountain ranges in the world, predictions of potential impacts of climate change on ecosystems are mainly based on modeling studies or on observations of inter-annual and spatial variability. There are only a few attempts to manipulate climatic conditions in situ. A combination of an experimental increase in CO2 and temperatures in the Alps has not been carried out before. In the proposed project, we enrich experimental plots with CO2 using a FACE approach and increase temperatures with heating cables at the soil surface. The experiment has already been set up at a treeline site near Davos. The CO2 enrichment was started in 2001 and increased CO2 concentration to 550 ppm. During the 6th year of operation, as part of a co-operation with a French team, a parallel soil warming treatment was installed on half of the test plots in a crossed design with the CO2 treatment, which successfully increases soil and air temperatures by 3K. We aim at investigating the interactive effects of elevated CO2 and warming on plant growth, biodiversity and ecosystem responses. Our proposed study addresses the following key questions: Will effects of elevated CO2 persist in the longer term and will these effects change under increased temperatures? How does biodiversity and the dominant vegetation, i.e. dwarf shrubs vs. trees, react to elevated CO2 and warming? How does elevated CO2 and warming affect key ecosystem functions such as nutrient uptake and decomposition? The focus will be on the two major tree species European larch and Mountain pine and on the dominant dwarf shrub species, especially Vaccinium myrtillus and V. uliginosum. Measurements of plant growth will include length increment, productivity, phenology and reproduction. Changes in biodiversity will be monitored

Bulk elemental and stable isotope data across the Cretaceous-Paleogene boundary

This study includes sample name, depth with respect to the Cretaceous-Paleogene (K/Pg) boundary (cm), percentage of calcium carbonate (%CaCO3), percentage of total organic carbon (%TOC), stable carbon isotope composition of bulk carbonate (d13Ccarb), stable oxygen isotope composition of bulk carbonate (d18Ocarb), stable carbon isotope composition of bulk organic carbon (d13Corg), stable nitrogen isotope composition of bulk organic matter (d15N), and stable carbon isotope composition of phytane (d13Cphytane) for 8 K/Pg boundaries in Tunisia (El Kef and Aïn Settara), Spain (Caravaca and Agost), France (Loya and Bidart, and Denmark (Kulstirenden and Højerup). The standard deviation for each parameter is reported when multiple analyses of the same sample were performed. Analytical reproducibility (1σ) was calculated as better than 0.1% for TOC and TN, 0.1‰ and 0.5‰ for d13Corg and d15N, and 0.04‰ and 0.09‰ for d13Ccarb and d18Ocarb by comparison with analytical standards (see main text for details).

Carbon and oxygen isotopic compositions of Permian and Carboniferous brachiopod shells from the United States and Russia, collected in 2008, along with metadata for shell preservation (cathodoluminescence, trace element compositions)

Carbon and oxygen isotopic compositions of Permian and Carboniferous brachiopod shells from Russia, the United States and various world-wide localities along with metadata for shell preservation (cathodoluminescence, trace element compositions)

To evaluate the isotopic record of climate change and carbon sequestration in the Late Paleozoic, we have compiled new and published oxygen and carbon isotopic measurements of more than 2000 brachiopod shells from Carboniferous through Middle Permian (359-260 Ma) strata worldwide. We focus on the isotopic records from the U.S. Midcontinent and the Russian Platform because these two regions provide well-preserved marine fossils spanning a broad time interval. Brachiopod shells were processed and screened for diagenesis by different methods depending on the research group. Some groups crush shells and pick clear crystals under the microscope. Five to ten milligrams of Ca carbonate are analyzed for trace and minor elements (Mg, Sr, Fe, Mn). Other research groups thin-section shells and use cathodoluminscence and plane light microscopy to screen for diagenesis. Nonluminescent shell is microsampled (0.05-0.1 mg) on the thin-section or complementary billet. All research groups use isotope ratio mass spectrometer for carbon (13C/12C) and oxygen (18O/16O) analyses. These data are used to examine paleotemperatures and their relation to climate in the past.

Untersuchungen zur Auswirkung von Landwirtschaft mit niedrigem und hohem Input auf die mikrobiologische Bodenaktivitaet und -gemeinschaft hinsichtlich einer nachhaltigen Landwirtschaft

Mikroorganismen nehmen im agrarisch genutzten Oekosystem Boden eine Schluesselrolle ein. Sie spielen eine zentrale Rolle bei der Mineralisierung und Transformierung der organischen Substanz des Bodens wie auch der zugefuehrten Duengemittel und Pflanzenrueckstaende. Kenntnisse ueber den Einfluss der Bewirtschaftungsweise auf die Menge, die Aktivitaet und die Zusammensetzung der Bodenmikroflora sind eine entscheidende Grundlage bei der Entwicklung nachhaltiger Bodennutzungssysteme. Zur Klaerung spezieller Fragen werden Langzeitversuche, mit Vergleichsvarianten verschiedener Anbausysteme herangezogen. Die spezifische Atmungsaktivitaet der mikrobiellen Biomasse wird als wichtiger Parameter des mikrobiellen Energiestoffwechsels ermittelt. Tracer Experimente dienen zur Quantifizierung des Kohlenstoff- und Energiehaushalts. Die Mikroorganismengemeinschaft wird an Hand funktioneller (Biolog) und struktureller (PLFA) Parameter ermittelt. Sowohl der Energiehaushalt als auch die Struktur der mikrobiellen Lebensgemeinschaft sind bestimmend fuer die Entwicklung oekologischer Sukzessionen. Sie werden im Sinne der Fragestellung angewendet um Agraroekosysteme aus verschiedenen Nutzungssystemen zu charakterisieren.

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