Please wait for the process to complete.
Checking for non-preferred file/folder path names (may take a long time depending on the number of files/folders) ...
This resource contains some files/folders that have non-preferred characters in their name. Show non-conforming files/folders.
||This resource does not have an owner who is an active HydroShare user. Contact CUAHSI (email@example.com) for information on this resource.|
|Storage:||The size of this resource is 1.3 MB|
|Created:||Feb 05, 2021 at 4 a.m.|
|Last updated:|| Apr 21, 2021 at 2:07 p.m.
|Citation:||See how to cite this resource|
|+1 Votes:||Be the first one to this.|
|Comments:||No comments (yet)|
This dataset includes the CO2 flux and the FTICR-MS data reported in https://doi.org/10.1007/s10533-021-00790-y.
CO2 flux data
CO2 fluxes were measured in a laboratory incubation. Approximately 20 g (oven dry weight equivalent, ODE) of soil was weighed into each of 44 glass microcosms (487 ml). Twenty ‘trace gas’ microcosms (5 per treatment) were repeatedly monitored for CO2 production and destructively harvested at the end of the experiment. For the initial 16 days, all microcosms were exposed to a 4-day oxic (compressed medical grade air)/4-day anoxic (flushing with N2) pre-incubation period to allow soil respiration to stabilize. After the pre-incubation period, all microcosms were amended with 180 mg 13C-labeled ground ryegrass litter (97 atom%, Isolife, Wageningen, Netherlands; ~6% of the soil’s native C content) and incubated for 44 days. Microcosms were split into four redox treatments, managed via headspace manipulation: (1) static anoxic (N¬2 gas), (2) static oxic (medical air), (3) 4 days oxic/4 days anoxic (high frequency), (4) 8 days oxic/4 days anoxic (low frequency). Both high and low frequency treatments started and ended with oxic phases. Headspace samples were collected approximately every 4 days from the 20 trace gas microcosms (4 redox regimes × 5 replicates) to assess fluxes of CO2 and 13C-CO2 concentrations. For fluctuating treatments, microcosms were sampled immediately before the redox conditions were altered. To measure CO2 fluxes, microcosms were temporarily sealed for 2 hours, and gas samples were collected at the beginning and end of the sealed period by removing 30 ml of the headspace via septa into pre-evacuated 20 ml glass vials. Microcosms were sealed for 3 hours when CO2 production rates decreased towards the end of the experiment. CO2 concentrations were measured on a gas chromatograph (GC-14A, Shimadzu, Columbia, MD), equipped with a thermal conductivity detector. CO2 fluxes were determined by calculating the concentration difference during the sealed period, assuming a linear flux rate. An extra set of gas samples collected from each microcosm after the sealed period was analyzed for the 13C/12C CO2 isotope ratio with an isotope ratio mass spectrometer (IRMS; IsoPrime 100, Elementar, Hanau, Germany).
Soil microcosms were destructively harvested at three timepoints during the experiment, on days 20 and 36 (n = 3 per treatment each day) and day 44 (n = 5 per treatment, the trace gas microcosms).
Samples exposed to an oxic headspace preceding the harvest were processed on the benchtop; those finishing an anoxic period were processed in an anoxic glove box (Coy Laboratory Products, Grass Lake, MI). 100 mg of soil (ODE) was shaken with water (2 ml) for 2 hours on an Eppendorf Thermomixer and centrifuged before collecting the supernatant. Water extracts were then desalted by solid phase extraction using Varian PPL cartridges according to Dittmar et al. (2008). A 12 T Bruker SolariX FTICR mass spectrometer was used to collect high resolution mass spectra of the organic compounds in the extracts. Refer to the GRE_13C_FTICR.R for instructions on processing the data in R.
This resource was created using funding from the following sources:
|Agency Name||Award Title||Award Number|
|US Department of Energy||Early Career Research Program Award||SCW1478|
|US Department of Energy||EMSL awards||48643, 48477, 48650, and 48832|
|National Science Foundation||DEB-1457805, EAR-1331841, DEB-0620910|
|US Department of Energy||DE-AC52-07NA27344|
|US Department of Energy||Biological and Environmental Research||SCW1632|
|National Institute of Food and Agriculture||McIntire Stennis||CA-B-ECO-7673-MS|
|US Department of Energy||grid.436923.9|
How to Cite
This resource is shared under the Creative Commons Attribution CC BY.http://creativecommons.org/licenses/by/4.0/
There are currently no comments