Maximizing vegetation representation of the catchment in sedimentary DNA with targeted cores in small lakes

Abstract

Sedimentary DNA is becoming an invaluable tool for biodiversity assessments across spatial and temporal scales. Accurate interpretation, however, requires a clear understanding of its origin and taphonomy, from transport to preservation processes within lake systems. Insights into these processes are crucial for developing efficient sampling methods for precise ecological monitoring. Our analysis of 42 adjacent surface sediment sample replicates shows that deeper, central samples, with reduced influence from aquatic taxa, exhibit greater taxonomic richness compared to near-shore samples. By comparing these results to systematic vegetation surveys, we demonstrate that central cores are optimal as they capture the main taxonomic richness in the catchment, while marginal samples near inflows are essential for detecting rarer, spatially restricted taxa. This study highlights the potential of central-core sampling to effectively capture vegetation profiles in small, bathymetrically simple lakes, while enhancing the understanding of DNA transport mechanisms in catchments with similar topographic or hydrological characteristics.