Kungsängen soil microbial communities

Study Extent

Soil samples were collected on June 7th, 2016, at Kungsängen Nature Reserve (N59°50’, E17°40’). Samples were taken from five locations 30 m apart on each side of the soil moisture transition border separated by 30 m across the transition border.

Sampling

Soil samples were taken with a soil corer when possible (5cm diameter x 10 cm depth), or with a hand shovel when soil was to wet (sampling depth and volume estimated to correspond to that of the soil cores). Soil samples were individually placed in plastic bags and kept on ice during sampling before storage at 4degC over night. The day after, soils were homogenized in the plastic bags and subsamples were transferred to 15ml conical centrifuge tubes and frozen at -20degC prior to freeze drying. Approximately 250 to 500 mg of freeze-dried soil was used for total DNA extraction. The entire ITS and partial LSU regions of rDNA, approximately 1500 bp, was amplified using a modified ITS1 primer and the LR5 primer. Both primers were indexed for multiplexing to allow pooling of the samples during sequencing. The pooled library was sequenced at SciLifeLab/NGI (Uppsala, Sweden) on the PacBio RSII sequencing platform.

Method steps

1. Sequence denoising and ASV creation was performed with DADA2 using the nfcore/ampliseq pipeline (https://nf-co.re/ampliseq), commit 5adaf23d7f. Taxonomy assignment was based on the ITS2 region and performed according to https://docs.biodiversitydata.se/analyse-data/molecular-tools/#taxonomy-annotation, using nf-core/ampliseq commit e1bdbfb623 and the database unite-alleuk=8.3 (UNITE general FASTA release for Eukaryotes - Version 8.3, https://doi.org/10.15156/BIO/1280127)

Kungsängen Nature Reserve (N59°50’, E17°40’) is a 12.5-hectare reserve in a larger meadow located in the south of Uppsala, Sweden, along the east shore of the Fyris River. Soil samples were taken across an abrupt moisture transition that divides the meadow community into a Carex acuta dominated plant community with low species richness in the wetter part, which is visually distinct from the mesic-dry part that has a species rich grass-dominated plant community including a high frequency of F. meleagris.