Conservation in a litre of air

Since Ficetola et al. (2008) alerted ecologists and conservation biologists to the existence of environmental DNA (eDNA), the number of studies using eDNA has exploded, with a rapidly increasing diversity of research, monitoring, and management objectives. Initial applications focused on amphibians and fishes while today's taxonomic targets span the phylogenetic tree. The environmental media that are sampled have expanded from freshwater to saltwater to soils, and, most recently, to air. In this issue of Molecular Ecology Resources, Lynggaard et al. (Molecular Ecology Resources, 2023) use eDNA captured on air filters to census vertebrate biodiversity in a forest. With a three day, six sample period, 143 sample effort in a nature park in a rural area of Zealand, Denmark, their wild species detections comprised about 25% of the terrestrial vertebrates that are known to occur in the area, including about 33% of the mammal, 17% of the bird, and 60% of the amphibian species. This study demonstrates that air sampling for eDNA has the potential to become a powerful standard method for terrestrial biodiversity assessment that is complementary to traditional methods (e.g., trapping, visual and acoustic observation, collection of scat and hair).