Landa, Susie N; Pacheco, Ava M; Haworth, Lorna E; Tanner, Richelle L: Plant community composition in Suisun Marsh tidal wetlands [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.987851 (dataset in review),

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In: Tanner, Richelle L: Community function under Phragmites invasion in Suisun Marsh CA [dataset bundled publication]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.987847 (dataset in review)

We conducted a monthly field study from January to December 2021 to characterize the plant community dynamics of three tidal wetlands experiencing Phragmites australis invasion in Suisun Marsh, located in the San Francisco Bay-San Joaquin Delta region of California. We sought to understand whether plant community composition (species richness, diversity) and habitat structure as facilitated by diverse canopies were impacted by the invasive plant canopy. The surveyed wetlands were Tule Red (38.128880, -121.980554), Hill Slough (38.232834, -122.020285), and Blacklock (38.183957, -121.889321). At Tule Red and Hill Slough, semi-permanent transects (n=19) were distributed in a paired design with Phragmites-invaded and native canopy areas along secondary and tertiary tidal channels within the wetlands, positioned perpendicular to the water channel. Transects were 20m in length with 1m2 quadrat sampling every five meters. At Blacklock, we established general plot areas, at which three 1m2 quadrat measurements were taken instead of sampling along the transect. This was done because of high inundation of the site and an ongoing herbicide study by the California Department of Water Resources, which we incorporated into our dataset: "treated Phragmites" refers to bare mudflat that was previously treated with imazapyr, glyphosate, and aquatic mowing. Within the 1m2 quadrats on the transects, a 0.25m2 sub-quadrat was placed at each corner (n=4 biological replicates per meter sampled). The following plant measurements were recorded: dominant species present and its shoot density, average shoot height (m), average shoot circumference (cm), life stage [growing, flowering (presence of flowers), senescing, dead (no green on stalk but standing), and litter]. We also recorded if other plant species were present within the sub-quadrat to calculate species richness.