Moss-Accumulated eDNA Is a Promising Source for Terrestrial Biodiversity Surveys Across the Tree of Life and Biomes

Developments in the environmental DNA (eDNA) field have revolutionised our ability to map biodiversity by providing cost-effective and non-invasive means to survey organisms across the tree of life. In the terrestrial realm, a variety of eDNA sources have been employed, but we lack easily accessible and cosmopolitan sources of terrestrial eDNA. Here we document the value of a novel eDNA source for mapping lifeforms across the tree of life in temperate and tropical ecosystems: mosses (Bryophytes). First, we analysed eDNA from 25 moss patches collected using three sampling methods (swabbing, moss stubs, and washes of moss stubs) across three sites in Denmark. We detected 26 vertebrate species, 54 invertebrate genera, 21 vascular plant genera, and 553 bacterial and 210 fungal genera. Swabbing was sufficient to obtain eDNA, eliminating the need for destructive sampling of mosses. Subsequently, employing the swabbing approach in gallery forest and savanna ecosystems in Côte d'Ivoire we assessed its use for vertebrate detections. Metabarcoding of 29 moss swabs yielded 18 bird, 13 mammal, and two amphibian genera, confirming its applicability in the tropics. Our findings expand the current biodiversity monitoring toolkit by capitalising on a cosmopolitan and readily available terrestrial eDNA source.