Sediment DNA analyses

SedaDNA studies have the potential to revolution the study of ecosystem changes and relate ecological processes to organism abundance changes over time. The method overcomes the limitation of taxonomic resolution of pollen and scarcity of macrofossils allowing more precise composition information for plants, but also allows for extracting information on animals. SedaDNA can be extracted from lake sediment cores at different depth of the core and the sediment can be used for DNA extraction followed by amplify DNA fragments of interest using PCR methods (metabarcoding) before sequencing. Metabarcoding is currently the most commonly used method, as it provides the highest taxonomic resolution for plants and can detect mammals well. After the sequencing of the libraries, bioinformatics processing is needed, which includes cleaning the data and matching the sedaDNA reads to a DNA reference library. Overall, sedaDNA provides a more complete understanding of past vegetation communities than has been possible before, and the availability of highly curated local DNA reference libraries reduces the chance of false identification, and such a reference library is now available for the Alps. The field is advancing towards standardization across different laboratories, which allows for pooling of datasets, and there are several large datasets available for further analysis. Hence, there is great potential in sedaDNA to obtain a better understanding of the drivers and processes of change in diversity through time and also forecast effects of ongoing climate on future biodiversity.