TY - JOUR

T1 - Metabarcoding of soil environmental DNA replicates plant community variation but not specificity

AU - Barnes, Christopher James

AU - Nielsen, Ida Broman

AU - Aagaard, Anne

AU - Ejrnæs, Rasmus

AU - Hansen, Anders Johannes

AU - Frøslev, Tobias Guldberg

N1 - Publisher Copyright: © 2022 The Authors. Environmental DNA published by John Wiley & Sons Ltd.

PY - 2022

Y1 - 2022

N2 - While metabarcoding of plant DNA from their environment is an exciting method that can supplement inventorying of live plant species, the accuracy and specificity has yet to be fully assessed over complex continuous landscapes. In this work, we evaluate plant community profiles produced via metabarcoding of soil by comparing them to a morphological survey. We assessed plant communities by metabarcoding of soil DNA in 130 sites along ecological gradients (nutrients, succession, moisture) in Denmark using chloroplast trnL region (10–143 bp) primer set and compared the resulting communities to communities produced with a longer nuclear ITS2 region (~216 bp) and a morphological survey. We found that the community variation observed within the morphological survey was well represented by molecular surveys, with significant correlation with both community composition and richness using both primer sets. While the majority of the ITS2 sequences could be assigned to species (over 80%), we had less success with the trnL sequences (70%), which was only possible after restricting the reference database to local species. We conclude that the community profiles produced by metabarcoding can be highly effective in performing large-scale macroecological studies. However, the discovery rates and taxonomic assignments produced via metabarcoding remained inferior to morphological surveys, but manual curation of databases improves the specificity of assignments made by the trnL primers, and improves the accuracy of the assignments made with the ITS2 primers. Finally, we suggest that a greater percentage of named diversity would be recovered by increasing soil sampling with the use of additional universal primer sets.

AB - While metabarcoding of plant DNA from their environment is an exciting method that can supplement inventorying of live plant species, the accuracy and specificity has yet to be fully assessed over complex continuous landscapes. In this work, we evaluate plant community profiles produced via metabarcoding of soil by comparing them to a morphological survey. We assessed plant communities by metabarcoding of soil DNA in 130 sites along ecological gradients (nutrients, succession, moisture) in Denmark using chloroplast trnL region (10–143 bp) primer set and compared the resulting communities to communities produced with a longer nuclear ITS2 region (~216 bp) and a morphological survey. We found that the community variation observed within the morphological survey was well represented by molecular surveys, with significant correlation with both community composition and richness using both primer sets. While the majority of the ITS2 sequences could be assigned to species (over 80%), we had less success with the trnL sequences (70%), which was only possible after restricting the reference database to local species. We conclude that the community profiles produced by metabarcoding can be highly effective in performing large-scale macroecological studies. However, the discovery rates and taxonomic assignments produced via metabarcoding remained inferior to morphological surveys, but manual curation of databases improves the specificity of assignments made by the trnL primers, and improves the accuracy of the assignments made with the ITS2 primers. Finally, we suggest that a greater percentage of named diversity would be recovered by increasing soil sampling with the use of additional universal primer sets.

KW - biodiversity

KW - biological monitoring

KW - ecology

KW - environmental DNA

KW - metabarcoding

KW - molecular ecology

KW - morphological survey

U2 - 10.1002/edn3.287

DO - 10.1002/edn3.287

M3 - Journal article

AN - SCOPUS:85125055109

VL - 4

SP - 732

EP - 746

JO - Environmental DNA

JF - Environmental DNA

SN - 2637-4943

IS - 4

ER -