Amplicon sequencing of pollen foraged by multiple bee species in units of the National Park Service, National Capital Region, 2021-2022

This study generated genetic 'metabarcode' data using high-throughput sequencing to characterize pollen foraging behavior of pollinating bee species on managed field habitat within units of the National Park Service. Specimens were collected within parks of the National Capital Region from 2021-2023 and subsequently identified to species or genus. DNA was then extracted from specimens using leg samples if pollen was adherent to the corbiculae ("pollen baskets") of corbiculate bees, otherwise using whole-body samples. 

This data release consists of three tab-delimited files and a file of DNA sequences:
1) sample.metadata.txt includes sample identifiers and the accessions they have been assigned by the National Center for Biotechnology Information (NCBI), the authoritative repository for publicly funded genetic data in the United States. These accessions can be used individually to obtain raw sequencing data or sample information at www.ncbi.nlm.nih.gov.  Alternatively, the BioProject accession PRJNA1236404 can be searched to retrieve the full set of data and sample accessions listed in the file. Entity and attribute metadata are provided for this file herein.
2) ITS2.raw.pollen.counts.txt includes the inferred taxon counts at the ITS2 locus, i.e. number of ITS2 sequences in a sample attributable to each identified taxon in each sample. 
3) potential.contaminants.txt lists plant taxa that were over-represented in negative controls samples within a particular sequence run. Values for these plant taxa in these runs should either be zeroed-out or adjusted based on a statistical model to account for potential sample contamination. Censoring data based on results in negative controls is a standard practice in metabarcoding. Many samples in this study were very small and/or had no visible pollen, which increases the potential for contamination as the endogenous DNA concentration is expected to be very low in these cases.
4) reference.db.fas contains the plant reference DNA sequences used for taxonomic assignment of the pollen sample sequences.