The analysis of environmental DNA (eDNA) is revolutionizing the monitoring of biodiversity as it allows to assess organismic diversity at large scale and unprecedented taxonomic detail. However, eDNA consists of an extracellular and intracellular fraction, each characterized by particular properties that determine the retrievable information on when and where organisms live or have been living. Here, we review the fractions of eDNA, describe how to obtain them from environmental samples and present a four-scenario concept that aims at enhancing spatial and temporal resolution of eDNA-based monitoring. Importantly, we highlight how the appropriate choice of eDNA fractions precludes misinterpretation of eDNA-based biodiversity data. Finally, future avenues of research towards eDNA fraction-specific analyses are outlined to unravel the full potential of eDNA-based studies targeting micro- and macro-organisms.
Keywords: allochthonous DNA; ancient DNA; biodiversity assessment; environmental DNA; extracellular DNA; intracellular DNA; metabarcoding; spatial resolution; temporal resolution.
© 2022 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd.