Trace gas activity of Mitchell Peninsula, Browning Peninsula and Robinson Ridge soils sampled in 2005 and 2019

This data was generated to compare the metabolic capacity (specifically relating to dihydrogen consumption rates) of Windmill Island soils sampled in 2005 and 2019.Soils were collected during separate expeditions occurring in 2005 and 2019. Soils were stored at -80°C prior to conducting this experiment in May 2019-July 2019. During each expedition, 5 soil samples were obtained from Mitchell Peninsula (66º31´S, 110º59´E), 3 from Browning Peninsula (66°27’S, 110°32’E). Soil samples were obtained from Robinson Ridge (66°22′S, 110°35′E) in 2019 only. Samples from all sites were sampled from along a longitudinal transect, with specific information for each sample included in the dataframe: - SampleID- Barcode of sample assigned by AAD upon sampling. “No soil control” indicates that no soil was included- this was an empty, sealed bottle as a negative control. “_HK” after the sample ID indicates that the soil included in this bottle was heat-killed by autoclaving as another negative control. - Site_Sampled- Indicates the site that the soil was sampled from - Transect_Information- Indicates the transect number and distance along the transect from which the soil was obtained. - Year_Sampled- Indicates what year/expedition the soil was sampled during - Timepoint (hrs)- Indicates how long after initial gas addition, in hours, that the H2_Concentration (ppb) reading was obtained - H2_Concentration (ppb)- Indicates the concentration of H2 contained in the sealed headspace as determined through gas analysis. Gas analysis: Soil samples (~2g) were added to separate, sterile 114 mL serum bottles and sealed with butyl rubber stoppers. Hydrogen was added to the otherwise ambient headspace to achieve an initial concentration of ~10 p.p.m.v, and the bottles were subsequently incubated at 10˚C. Headspaces were periodically sub-sampled (2 ml) using a gas-tight syringe (VICI Precision Sampling) and the partial pressure of hydrogen quantified using a Peak Performer 1 Reducing Compound Photometer (RCP) (910- Series). Changes in headspace hydrogen concentrations were confirmed to result from biological activity through the parallel monitoring of a heat-killed soil sample (121 °C, 15 p.s.i., 20 min) from each site and a serum bottle containing no soil.Sample Collection: During the 2005 and 2019 Windmill Island expeditions Data Collection:May-July 2019