Assessing arctic flora composition in the Siberian treeline ecotone by vegetation mapping, pollen analyses and sedimentary DNA metabarcoding

• Main Authors: Niemeyer, Bastian, Epp, Laura, Herzschuh, Ulrike, Pestryakova, L. A.
• Format: Conference Object
• Language: unknown
• Published: 2015
• Subjects: Arctic; Taymyr; Betula nana
• Online Access: https://epic.awi.de/id/eprint/41408/; https://epic.awi.de/id/eprint/41408/2/B_Niemeyer_INQUA.pdf; https://hdl.handle.net/10013/epic.48352; https://hdl.handle.net/10013/epic.48352.d002

Arctic environments are one of the most climatically influenced areas worldwide. These influences are currently causing major changes in vegetation composition, for example in the Taymyr lowlands, which harbour the northernmost boreal-arctic treeline areas of the world. The most dominant species of the treeline ecotone in this region are Larix gmelinii, Betula nana and Alnus viridis. They are presently shifting in density and range, and have done so multiple times throughout the Holocene. To understand the vegetation changes it is necessary to investigate the current state, before deducing changes for other time phases of the Holocene. To this end a field campaign was carried out at the Taymyr lowlands in 2013 to perform a multidisciplinary investigation by combining methods from vegetation mapping, palynological records and sedimentary DNA metabarcoding. We sampled lake sediments and mapped the vegetation along a transect spanning the treeline ecotone, with changing vegetation composition and density. Our results of the surveyed vegetation will help to investigate the current state of vegetation and will also be used as calibration of the pollen and DNA metabarcoding records. The comparison of the vegetation and pollen record will allow the assessment of over- or underrepresentation of certain taxa within the pollen signal, and this will enable a more secure interpretation of historic pollen records. We will also test this for the DNA metabarcoding data, which has not yet been systematically done for lake sediments in arctic latitudes. This multidisciplinary investigation will draw a more comprehensive image of the current vegetation composition at the Taymyr lowlands than has been possible to date, and will enable a more secure interpretation of historical vegetation change in this highly dynamic area.