This dataset contains dissolved inorganic/organic carbon (DIC/DOC) concentrations, its stable isotope ratios (δ13CDIC/DOC), partial pressure of carbon dioxide in the water column pCO₂(aq) (pCO2(aq)) and area-integrated CO₂ emission rates derived from flux calculations (FCO2; g C d⁻¹), along with corresponding parameters (temperature, pH, calcium, bicarbonate) collected from the Danube River and its key tributaries during five seasonal sampling campaigns in 2023 and 2024. Water samples were collected using a weighted 2 L sampling bottle submerged 1–2 meters below the surface, with sampling conducted from the river center via bridges or passenger boats, and occasionally from the riverbank. In situ temperature measurements were taken with a multiparameter instrument (HQ40d, HACH™, Loveland, CO, USA). δ13ODIC/DOC was analyzed using a OI Analytical Aurora 1030W-IRMS. This dataset is providing valuable insights into carbon dynamics in a large river system and support investigations of biogeochemical cycling. It further can inform ecosystem management and conservation strategies under changing environmental conditions.
The dataset contains calibrated isotopic data (∆13C, ∆15N) and relative biomasses of spiders and ground beetles, sampled in 2019 in Lower Saxony, Germany, within the RTG 2300 project "Enrichment of European beech forests with conifers". Arthropods were sampled with pitfall traps and identified to species level by Kriegel et al (2021) and Matevski and Schuldt (2023). Natural abundance isotopic ratios (δ13C, δ15N) were determined by the Centre for Stable Isotope Research Analysis at the University of Göttingen and thereafter calibrated with leaf litter isotopic ratios. Calibrated isotopic values (∆) were used to calculate multidimenional isotopic metrics, which were compared between different stand types and regions. The stand types were Douglas fir, beech-Douglas fir, beech, beech-spruce and spruce.