Laboratory sample processing
We used morphological traits to identify insects to family. After
identification, we dried insect samples at 60 ºC for 7 days before
collecting total dried insect biomass for each plot. We sent soil
microbial samples (collected in 2019 (WY) and 2020 (MT)) to Oregon State
University’s Center for Genome Research and Biocomputing for extraction,
amplification, cleanup, and sequencing to generate 250-bp paired-end
reads. We then merged the forward and reverse reads using FLASH (Magoč
and Salzberg 2011) and the merged reads were quality-controlled using
the DADA2 pipeline (Callahan et al. 2016) in Qiime2 (Hall and Beiko
2018). This removed chimeras, and the data were filtered to further
remove mitochondria, chloroplast, and unassigned sequences. We then
removed any amplicon sequence variants with fewer than 10 reads and
clustered sequences into operational taxonomic units (OTUs) with a 97%
similarity threshold using the Silva database (Pruesse et al. 2007) for
reference. We continued to follow the Qiime2 pipeline at a sampling
depth of 30,000, which only excluded one plot with less than 8,000
reads.