Fig. 1: 9 freshwater wetlands were examined to determine linkages between microbial communities and predictions of methane flux.

a Figure modified from Delwiche et al. ²⁶ shows the mean annual methane (CH₄) flux from wetlands included in FLUXNET-CH₄. The deviation of the predictions from observations indicates this abiotic variable incompletely represented CH₄ flux, especially for the highest emitting wetlands. Colored points represent sites discussed in this study. Methane fluxes vary across an extremely large range, spanning many (3–5) orders of magnitude. For that reason, many statistical analyses of methane flux that compare multiple sites, some with high emissions and some with low emissions, use, and graph methane fluxes at a logarithmic scale. b Wetlands differ by type, size, geography, and climatic factors. In this study, we investigated 5 marsh sites (OWC, PPR P7, PPR P8, LA2, and TWI), 1 swamp (JLA), 1 fen (STM-fen), and 2 bogs (STM-bog and SPRUCE). 7 of the sites were found across the United States and 2 were in northern Sweden. Aerial images of each site were acquired from Google Earth. c Upset plot indicates the total number of 16S rRNA samples (n = 1112 samples) and their distribution across relevant categories including wetland type, sampling month, and sampling depth. Intersection size represents the number of samples found across each combination of wetland type, month, and sample depth scenario and set size represents the total number of samples found within each variable. Source data are provided as a Source Data file.