The dataset contains carbon dioxide and methane emissions, as well as resorufin production (as a proxy for microbial metabolic activity) and dissolved oxygen concentrations, resulting from laboratory incubation experiments of streambed sediments. The sediments were collected from the upper 10 centimetres of the streambed in the River Tern and the River Lambourn in September 2015, with three samples collected from each river. These samples were collected from three areas: silt-dominated sediment underneath vegetation (fine), sand-dominated sediment from unvegetated zones (medium) and gravel-dominated sediment from unvegetated zones (coarse). The sediment was used in laboratory incubation experiments to determine the effect of temperature, organic matter content, substrate type and geological origin on streambed microbial metabolic activity, and carbon dioxide and methane production.
The work was carried out as part of a Natural Environment Research Council (NERC) funded PhD (NERC award number 1602135). The work was also part funded through the Seventh Framework Programme (EU grant number 607150).
Publication date: 2018-05-04
Sediment was collected using a shovel before being sieved (0.8 cm for fine, and 1.6 cm for medium and coarse) and homogenised prior to storage. The sediment was stored airtight in the cold and dark. Sediment of varying organic matter content from two geological origins (chalk and sandstone) was incubated at five temperatures (5, 9, 15, 21 and 26°C). Resorufin production was measured using a GGUN-FL30 on-line fluorometer, dissolved oxygen was measured using a Pyro-science Firesting fixed needle-type probe, and carbon dioxide and methane concentrations were measured using an Agilent 7890A Gas Chromatograph - Flame Ionisation Detector. The carbon dioxide and methane concentrations were converted to production per hour by calculating the difference in concentration between zero and five hours and normalising the production by the length of the incubation period. The data was then converted to emissions per volume of dry sediment using the Bunsen coefficient and the volume of sediment in each jar, resulting in units of milligrams of carbon per square metre per hour. Greenhouse gas concentrations were corrected for any machine drift using results from a standard gas mixture ran periodically during gas analysis. The resorufin concentration was converted to production per hour by calculating the difference in concentration between zero and five hours and normalising the production by the length of the incubation period. The production was then normalised by the concentration of resazurin added to the jar, resulting in units of nanograms of resorufin per microgram of resazurin per hour. Data were entered into an Excel spreadsheet and exported as a comma separated value file (.csv) for ingestion into the EIDC.