Enhanced Reconstruction of Holocene Bryophytes From Sedimentary Ancient DNA Using Bryophyte‐Targeted Primers

ABSTRACT The Arctic is warming rapidly, yet long‐term data on how this affects bryophytes, key components of Arctic vegetation, remain limited. Sedimentary ancient DNA (sedaDNA) provides high‐resolution taxonomic insights that can reveal vegetational responses to past environmental change, including functional responses via trait associations, but effective genomic tools for bryophyte sedaDNA are lacking. We applied bryophyte‐targeted primers targeting p6 loop in plastid DNA and compared their performance with bryophyte bycatch from vascular plant‐specific primers. Using data from bryophyte‐targeted primers, we analyzed richness patterns across environmental gradients and assessed their potential for environmental reconstruction. The primers resolved nearly 60% of taxa to species level and over 80% to genus level, recovering 2.63 times more taxa with 1.48 times higher species‐level resolution than vascular plant‐specific primers. Taxonomic richness increased nonlinearly over time and along with precipitation gradients while exhibiting a unimodal relationship with temperature and glacial activity. High‐resolution data also enabled trait assignments for most bryophyte taxa, allowing temporal analyses of community development and functional dynamics. Overall, our results demonstrated that bryophyte‐targeted primers substantially improved bryophyte recovery from sedaDNA and, when combined with trait information, provide a powerful approach for reconstructing past bryophyte ecosystems and investigating functional ecological dynamics under long‐term environmental change.