Data from: How quantitative is metabarcoding: a meta-analytical approach

Metabarcoding has been used in a range of ecological applications such as
taxonomic assignment, dietary analysis, and the analysis of environmental
DNA. However, after a decade of use in these applications there is little
consensus on the extent to which proportions of reads generated
corresponds to the original proportions of species in a community. To
quantify our current understanding we conducted a structured review and
meta-analysis. The analysis suggests that a weak quantitative relationship
may exist between the biomass and sequences produced (slope =0.52 ±0.34,
p<0.01)), albeit it with a large degree of uncertainty. None of the
tested moderators: sequencing platform type, the number of species used in
a trial, or the source of DNA were able to explain the variance. Our
current understanding of the factors affecting the quantitative
performance of metabarcoding is still limited: additional research is
required before metabarcoding can be confidently utilised for quantitative
applications. Until then, we advocate the inclusion of mock communities
when metabarcoding as this facilitates direct assessment of the
quantitative ability of any given study.