FIGURE 2.

Relative frequencies of methods used during seven methodological stages in DNA metabarcoding of bulk samples from 64 studies published between 2010 and 2019, including sample type, target species group, preservation, DNA extraction, marker, PCR profile and sequencing platform. The thickness of the lines corresponds to the number of papers using this method. “NA” represents studies where the corresponding stage/method was not reported or was not needed. The diagram was created with sankeymatic (http://sankeymatic.com/build/)