API src

Found 18 results.

Trennung der Komponenten des CO2 Gaswechsels von Pflanzenbeständen im Licht

Photosynthese und Respiration - die zwei dominierenden Komponenten des C-Haushaltes von Pflanzen und Ökosystemen - lassen sich mit konventionellen Methoden der Gaswechselmessung nicht mit befriedigender Präzision trennen. Dieser Sachverhalt begründet Defizite im Verständnis des C- und Energiehaushaltes von Kulturpflanzen und Ökosystemen. Im vorliegenden Vorhaben sollen neuartige CO2 Gaswechselmesstechniken in Kombination mit der kontinuierlichen Messung der C- und O-isotopischen Signaturen (d13C und d18O) des CO2 eingesetzt werden, um Photosynthese und Respiration eines Pflanzenbestandes im Licht zu quantifizieren und zu trennen. Grundlage hierfür ist die Bestimmung der natürlich entstehenden Unterschiede in der C- und O-isotopischen Signatur von photosynthetischen und respiratorischen CO2-Flüssen. Diese Ergebnisse werden mit Schätzwerten aus Untersuchungen mit anderen Methoden verglichen. In den Experimenten sollen Photosynthese, Respiration, Wachstum und Assimilateverteilung der Bestände durch differenzielle N-Ernährung manipuliert und deren Auswirkung auf die 13C- und 18O-Signaturen des respirierten und fixierten CO2 charakterisiert werden. Mit den gewonnenen Daten lässt sich erstmalig die Übertragbarkeit der bislang nur auf der Skala von Blättern verifizierten Modelle zur C- und O-Isotopendiskriminierung auf die Skala von Pflanzenbeständen und Ökosystemen überprüfen.

Water isotope values from northeastern German lake systems 2020 et seq

Water isotopes (δ2H and δ18O) were analyzed in samples collected in lakes associated to major riverine systems in northeastern Germany throughout 2020. The dataset is derived from water samples taken at a) lake shores (sampled in March and July 2020); b) buoys temporarily installed in deep parts of the lake (sampled monthly from March to October 2020); c) multiple spatially distributed spots in four selected lakes (in September 2020); d) the outflow of Müggelsee (sampled biweekly from March 2020 to January 2021). At shores, water was sampled with a pipette from 40-60 cm below water surface and directly transferred into a measurement vial, while at buoys a Limnos water sampler was used to obtain samples from 1 m below surface. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. The data give information about the seasonal isotope amplitude in the sampled lakes and about spatial isotope variability in different branches of the associated riverine systems.

Stable oxygen isotope ratios of tree-ring cellulose from oak (Quercus robur) at Lake Tiefer See, Mecklenburg Lake District, Northeastern Germany

Methods

Water isotope time series (March 2020 - March 2021) of samples collected along the Zingster Bodden chain

Time series of stable isotopes (δ2H and δ18O) were analyzed in water samples collected at the Zingster Bodden chain in biweekly to monthly intervals between March 2020 and March 2021. Herefore, a Limnos sampler was used to obtain water from 0.5 to 1 m below surface. In the laboratory, a WTW 1970i conductivity meter and TetraCon 325 measuring cell were used to analyse electrical conductivity. Sub-samples were transferred into measurement vials before isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured with regularly calibrated WTW multiparameter devices. The data give information about the seasonal isotope amplitude at the sampled locations and about spatial variability along the transects.

Water isotope values from estuarine systems along the German Baltic Sea coast

Stable isotopes (δ²H and δ¹⁸O) were analyzed in water samples collected at the German Baltic Sea Coast. Transect samples were taken in June 2019, March 2020, and July 2021 at 68 spots along the Schlei, the Zingster Bodden chain, and the Rügener and Greifswalder Boddens. Additionally, at selected spots time series were sampled in biweekly to monthly intervals between March 2020 and March 2021. At shores, water was sampled with a pipette from 0.3 to 0.6 m below water surface and directly transferred into a measurement vial. In deeper parts of the boddens a Limnos sampler was used to obtain water from 0.5 to 1 m below surface. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. The measurement uncertainty was quantified by error propagation, including the parameters a) uncertainties of lab standards; b) errors of standard calibration; c) average standard deviation of replicate measurements. Based on this, measurement uncertainty was estimated to account 0.16 ‰ for δ¹⁸O and 0.57 ‰ for δ²H. Water chemical parameters were measured with WTW measurement devices. The data give information about a) the seasonal isotope amplitude at the sampled locations; b) spatial variability along the transects, and c) the correlation between isotopes and water chemical parameters.

Water isotope time series (March 2020 - March 2021) of samples collected at A. P. Møller Skolen, Kleine Breite, Schlei

Time series of stable isotopes (δ2H and δ18O) were analyzed in water samples collected near the A. P. Møller Skolen, Schleswig (Kleine Breite, Schlei), in biweekly to monthly intervals between March 2020 and March 2021. Water was sampled with a pipette from ca. 0.5 m below water surface and directly transferred into a measurement vial. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured in-situ with a modular WTW 3440 multiparameter devices and regularly calibrated conductivity cells (MPP 930 IDS, TetraCon® 925-P). The data give information about the seasonal isotope amplitude at the sampled locations and about spatial variability along the transects.

Water isotope time series (March 2020 - March 2021) of samples collected in Kloster, Hiddensee

Time series of stable isotopes (δ2H and δ18O) were analyzed in water samples taken near the harbour of Kloster (Hiddensee), in biweekly to monthly intervals between March 2020 and March 2021. Water was sampled with a pipette from ca. 0.5 m below water surface and directly transferred into a measurement vial. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured in-situ with WTW multiparameter measurement devices. The data give information about the seasonal isotope amplitude at the sampled locations and about spatial variability along the transects.

Water isotope values and chemical parameters in time series samples (March 2020 - January 2021) from Müggelsee, Germany

Water isotopes (δ2H and δ18O) were analyzed in samples collected in lakes associated to major riverine systems in northeastern Germany throughout 2020. This sub-dataset is derived from water samples taken before the outflow of Müggelsee. Sampling was conducted biweekly from March 2020 to January 2021. Samples were taken with a pipette from 40-60 cm below water surface and directly transferred into a measurement vial. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical and physical parameters are daily average values derived from the Müggelsee long-term data monitoring station (https://emon.igb-berlin.de/grosser_mueggelsee.html). The data give information about the seasonal isotope amplitude at Müggelsee over the studied time period.

Water isotope values from a spatial campaign conducted in four northeastern German lakes in September 2020

Water isotopes (δ2H and δ18O) were analyzed in samples collected in lakes associated to major riverine systems in northeastern Germany throughout 2020. This sub-dataset is derived from water samples taken at multiple spatially distributed spots in four selected lakes. A Limnos water sampler was used to obtain samples from 1 m below water surface on 29th and 30th September 2020. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer.

Water isotope values in time series samples (March - October 2020) collected at buoys deployed in northeastern German lake systems

Water isotopes (δ2H and δ18O) were analyzed in samples collected in lakes associated to major riverine systems in northeastern Germany throughout 2020. This sub-dataset is derived from water samples taken at buoys temporarily installed in deep parts of the lake. Samples were taken monthly to bimonthly from March to October 2020. A Limnos water sampler was used to obtain samples from 1 m below water surface. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water temperatures were measured in similar depths with an Aqua TROLL 600 multiparameter sonde (In-Situ, Fort Collins, CO, USA). The data give information about the seasonal isotope amplitude in the sampled lakes and about spatial isotope variability in different branches of the associated riverine systems.

1 2