Breaking ground: Plant diversity assessments through soil eDNA metabarcoding

Abstract

Biodiversity assessments are crucial for understanding the state and threats to nature. While plants play a central role in these assessments, traditional methods for identifying plant diversity based on physical traits can be time-consuming and require specialized skills. However, new advances in DNA analysis have opened up possibilities for expedited and cost-effective identification of biodiversity. The analysis of DNA from environmental samples, such as air, soil, and water, can detect many organisms in a single effort. However, the spatial and temporal signals of plant environmental DNA (eDNA) present in these samples are not well understood, limiting the conclusions that can be drawn from eDNA assessments. The focus of the research is on soil eDNA samples, which is where most plant DNA accumulates. The thesis includes two peer-reviewed book chapters that review current knowledge about plant eDNA samples and DNA from soil, and two original research articles that evaluate the power of soil eDNA assessments to monitor plant diversity and determine ecosystem types. The research shows how soil eDNA samples can be used to diagnose local, regional, past, and present plant diversity, as well as aid in the characterization of forest types. These findings have broad applications, from site-specific assessments to land-cover mapping, providing a baseline for decision-making in soil eDNA studies. Overall, DNA-based identification is a critical tool for meeting the biodiversity challenges of the twenty-first century.