Data from: Plant DNA metabarcoding of lake sediments: how does it represent the contemporary vegetation

Metabarcoding of lake sediments have been shown to reveal current and past
biodiversity, but little is known about the degree to which taxa growing
in the vegetation are represented in environmental DNA (eDNA) records. We
analysed composition of lake and catchment vegetation and vascular plant
eDNA at 11 lakes in northern Norway. Out of 489 records of taxa growing
within 2 m from the lake shore, 17-49% (mean 31%) of the identifiable taxa
recorded were detected with eDNA. Of the 217 eDNA records of 47 plant taxa
in the 11 lakes, 73% and 12% matched taxa recorded in vegetation surveys
within 2 m and up to about 50 m away from the lakeshore, respectively,
whereas 16% were not recorded in the vegetation surveys of the same lake.
The latter include taxa likely overlooked in the vegetation surveys or
growing outside the survey area. The percentages detected were 61, 47, 25,
and 15 for dominant, common, scattered, and rare taxa, respectively.
Similar numbers for aquatic plants were 88, 88, 33 and 62%, respectively.
Detection rate and taxonomic resolution varied among plant families and
functional groups with good detection of e.g. Ericaceae, Roseaceae,
deciduous trees, ferns, club mosses and aquatics. The representation of
terrestrial taxa in eDNA depends on both their distance from the sampling
site and their abundance and is sufficient for recording vegetation types.
For aquatic vegetation, eDNA may be comparable with, or even superior to,
in-lake vegetation surveys and may therefore be used as an tool for
biomonitoring. For reconstruction of terrestrial vegetation, technical
improvements and more intensive sampling is needed to detect a higher
proportion of rare taxa although DNA of some taxa may never reach the lake
sediments due to taphonomical constrains. Nevertheless, eDNA performs
similar to conventional methods of pollen and macrofossil analyses and may
therefore be an important tool for reconstruction of past vegetation.