This spatially intensive synoptic survey (Approach 3) was designed in support of the sampling goals of the NSF EPSCoR funded Aquatic Intermittency effects on Microbiomes in Streams (AIMS) Project (OIA 2019603). During June 2022, a field team co-collected datasets characterizing the hydrology, biogeochemistry, and microbiome across 49 sampling locations within a sub-drainage of the Talladega National Forest (Alabama, USA). The Talladega National Forest is in northeastern Alabama situated between the Valley and Ridge and Piedmont physiographic provinces. The sites were selected to balance multiple competing priorities: (i) strategically targeting existing monitoring infrastructure with long-term data; (ii) including sites near several known springs and tributary junctions; and (iii) including a range of drainage area and topographic wetness index (TWI) values, both of which have been correlated with flow permanence. Briefly, the sites selected based on drainage area and TWI were chosen by binning drainage area into 10 bins and then binning TWI into quintiles within each drainage area bin. We then randomly selected a point in each bin after accounting for points selected based on existing infrastructure, springs, and tributaries, as well as enforcing a minimum spacing of 100 m between locations. We then made minor adjustments to points to account for field conditions, for instance adjusting locations with respect to a road crossing.

This resource specifically includes the synoptic (Approach 3) Membrane Inlet Mass Spectrometer (MIMS) dissolved gas data set, including Argon (Ar), Oxygen (O2), Nitrogen (N2), N2:Ar ratio, and O2:Ar ratio, that was collected by the biogeochemistry team to better understand the effects of stream drying on dissolved gases in the southeastern US. Included in the Content section is the approach 3 sampling datasheet that was used during field collection and one excel file.The excel file contains the synoptic sampling event: June 9, 2022 to June 10, 2022. The naming format for the excel file is as follows: MIMS_SE_Approach3_StartYYYYMMDD_EndYYYYMMDD_Version#. Within the excel file, the 'Working Files' tab includes raw data directly from the MIMS with the coolest standard at 17 degrees C and the warmest standard water bath at 22 degrees C. The 'Working Files_1' tab contains the processed MIMS data before taking averages of all the replicates. The raw MIMS data was processed and calculated via the R package 'MIMSY' and has 3 data points per replicate as shown in the 'Working Files_1' tab. The 'Final Data' tab has the data that should be used for analyses with the averages of all 3 replicates and standard deviations (sd) in uM units.

AIMS OSF Site: https://osf.io/e7s9j/