TY - THES A1 - Niemeyer, Bastian T1 - Vegetation reconstruction and assessment of plant diversity at the treeline ecotone in northern Siberia Y1 - 2016 ER - TY - JOUR A1 - Niemeyer, Bastian A1 - Epp, Laura Saskia A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Pestryakova, Luidmila Agafyevna A1 - Herzschuh, Ulrike T1 - A comparison of sedimentary DNA and pollen from lake sediments in recording vegetation composition at the Siberian treeline JF - Molecular ecology resources N2 - Reliable information on past and present vegetation is important to project future changes, especially for rapidly transitioning areas such as the boreal treeline. To study past vegetation, pollen analysis is common, while current vegetation is usually assessed by field surveys. Application of detailed sedimentary DNA (sedDNA) records has the potential to enhance our understanding of vegetation changes, but studies systematically investigating the power of this proxy are rare to date. This study compares sedDNA metabarcoding and pollen records from surface sediments of 31 lakes along a north-south gradient of increasing forest cover in northern Siberia (Taymyr peninsula) with data from field surveys in the surroundings of the lakes. sedDNA metabarcoding recorded 114 plant taxa, about half of them to species level, while pollen analyses identified 43 taxa, both exceeding the 31 taxa found by vegetation field surveys. Increasing Larix percentages from north to south were consistently recorded by all three methods and principal component analyses based on percentage data of vegetation surveys and DNA sequences separated tundra from forested sites. Comparisons of the ordinations using procrustes and protest analyses show a significant fit among all compared pairs of records. Despite similarities of sedDNA and pollen records, certain idiosyncrasies, such as high percentages of Alnus and Betula in all pollen and high percentages of Salix in all sedDNA spectra, are observable. Our results from the tundra to single-tree tundra transition zone show that sedDNA analyses perform better than pollen in recording site-specific richness (i.e., presence/absence of taxa in the vicinity of the lake) and perform as well as pollen in tracing vegetation composition. KW - environmental DNA KW - metabarcoding KW - pollen KW - Siberia KW - trnL marker KW - vegetation Y1 - 2017 U6 - https://doi.org/10.1111/1755-0998.12689 SN - 1755-098X SN - 1755-0998 VL - 17 SP - e46 EP - e62 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Niemeyer, Bastian A1 - Herzschuh, Ulrike A1 - Pestryakova, Luidmila Agafyevna T1 - Vegetation and lake changes on the southern Taymyr peninsula, northern Siberia, during the last 300 years inferred from pollen and Pediastrum green algae records JF - The Holocene : an interdisciplinary journal focusing on recent environmental change N2 - Siberian arctic vegetation and lake water communities, known for their temperature dependence, are expected to be particularly impacted by recent climate change and high warming rates. However, decadal information on the nature and strength of recent vegetation change and its time lag to climate signals are rare. In this study, we present a Pb-210/Cs-137 dated pollen and Pediastrum species record from a unnamed lake in the south of the Taymyr peninsula covering the period from AD 1706 to 2011. Thirty-nine palynomorphs and 10 morphotypes of Pediastrum species were studied to assess changes in vegetation and lake conditions as probable responses to climate change. We compared the pollen record with Pediastrum species, which we consider to be important proxies of climate changes. Three pollen assemblage zones characterised by Betula nana, Alnus viridis and Larix gmelinii (1706-1808); herbs such as Cyperaceae, Artemisia or Senecio (1808-1879), and higher abundance of Larix pollen (1955-2011) are visible. Also, three Pediastrum assemblage zones show changes of aquatic conditions: higher abundances of Pediastrum boryanum var. brevicorne (1706-1802); medium abundances of P. kawraiskyi and P. integrum (1802-1840 and 1920-1980), indicating cooler conditions while less eutrophic conditions are indicated by P. boryanum, and a mainly balanced composition with only small changes of cold- and warm-adapted Pediastrum species (1965-2011). In general, compositional Pediastrum species turnover is slightly higher than that indicated by pollen data (0.54 vs 0.34 SD), but both are only minor for this treeline location. In conclusion, the relevance of differentiation of Pediastrum species is promising and can give further insights into the relationship between lakes and their surrounding vegetation transferred onto climatic conditions. KW - morphotypes KW - Pediastrum KW - pollen KW - Siberia KW - treeline KW - vegetation Y1 - 2015 U6 - https://doi.org/10.1177/0959683614565954 SN - 0959-6836 SN - 1477-0911 VL - 25 IS - 4 SP - 596 EP - 606 PB - Sage Publ. CY - London ER - TY - GEN A1 - Niemeyer, Bastian A1 - Herzschuh, Ulrike A1 - Pestryakova, Luidmila Agafyevna T1 - Vegetation and lake changes on the southern Taymyr peninsula, northern Siberia, during the last 300 years inferred from pollen and Pediastrum green algae records T2 - The Holocene N2 - Siberian arctic vegetation and lake water communities, known for their temperature dependence, are expected to be particularly impacted by recent climate change and high warming rates. However, decadal information on the nature and strength of recent vegetation change and its time lag to climate signals are rare. In this study, we present a Pb-210/Cs-137 dated pollen and Pediastrum species record from a unnamed lake in the south of the Taymyr peninsula covering the period from AD 1706 to 2011. Thirty-nine palynomorphs and 10 morphotypes of Pediastrum species were studied to assess changes in vegetation and lake conditions as probable responses to climate change. We compared the pollen record with Pediastrum species, which we consider to be important proxies of climate changes. Three pollen assemblage zones characterised by Betula nana, Alnus viridis and Larix gmelinii (1706-1808); herbs such as Cyperaceae, Artemisia or Senecio (1808-1879), and higher abundance of Larix pollen (1955-2011) are visible. Also, three Pediastrum assemblage zones show changes of aquatic conditions: higher abundances of Pediastrum boryanum var. brevicorne (1706-1802); medium abundances of P. kawraiskyi and P. integrum (1802-1840 and 1920-1980), indicating cooler conditions while less eutrophic conditions are indicated by P. boryanum, and a mainly balanced composition with only small changes of cold- and warm-adapted Pediastrum species (1965-2011). In general, compositional Pediastrum species turnover is slightly higher than that indicated by pollen data (0.54 vs 0.34 SD), but both are only minor for this treeline location. In conclusion, the relevance of differentiation of Pediastrum species is promising and can give further insights into the relationship between lakes and their surrounding vegetation transferred onto climatic conditions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 421 KW - morphotypes KW - Pediastrum KW - pollen KW - Siberia KW - treeline KW - vegetation Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-404882 VL - 25 IS - 4 ER - TY - JOUR A1 - Niemeyer, Bastian A1 - Klemm, Juliane A1 - Pestryakova, Luidmila Agafyevna A1 - Herzschuh, Ulrike T1 - Relative pollen productivity estimates for common taxa of the northern Siberian Arctic JF - Review of palaeobotany and palynology : an international journal N2 - Pollen productivity estimates (PPE) are used to quantitatively reconstruct variations in vegetation within a specific distance of the sampled pollen archive. Here, for the first time, PPEs from Siberia are presented. The study area (Khatanga region, Krasnoyarsk territory, Russia) is located in the Siberian Sub-arctic where Larix is the sole forest-line forming tree taxon. Pollen spectra from two different sedimentary environments, namely terrestrial mosses (n = 16) and lakes (n = 15, median radius similar to 100 m) and their surrounding vegetation were investigated to extract PPEs. Our results indicate some differences in pollen spectra between moss and lake pollen. Larix and Cyperaceae for example obtained higher representation in the lacustrine than in terrestrial moss samples. This highlights that in calibration studies, modem and fossil datasets should use archives of similar sedimentary origin. Results of an Extended R-Value model were applied to assess the relevant source area of pollen (RSAP) and to calculate the PPEs for both datasets. As expected, the RSAP of the moss samples was very small (about 10 m) compared to the lacustrine samples (about 25 km). Calculation of PPEs for the six most common taxa yielded generally similar results for both datasets. Relative to Poaceae (reference taxon, PPE = 1) Betula nana-type (PPEmoss: 1.8, PPElake: 1.8) and Alnus fruticosa-type (PPEmoss:6.4, PPElake:2.9) were overrepresented while Cyperaceae (PPEmoss:0.5, PPElake:0.1), Ericaceae (PPEmoss: 0.3, PPElake <0.01), Salix (PPEmoss:0.03, PPElake <00.1) and Larix (PPEmoss: <0.01, PPElake:0.2) were under-represented in the pollen spectra compared to the vegetation in the RSAP. The estimation for the dominant tree in the region, Larix gmelinii, is the first published result for this species, but needs to be considered very preliminary. The inferred sequence from over- to under-representation is mostly consistent with results from Europe; however, the absolute values show some differences. Gathering vegetation data was limited by the remoteness of our study area and a lack of high-resolute satellite imagery and vegetation maps. Our estimate may serve as a first reference to strengthen future vegetation reconstructions in this climate-sensitive region. (C) 2015 Elsevier B.V. All rights reserved. KW - Lacustrine surface samples KW - Moss samples KW - Extended R-Value model KW - Pollen source area KW - Khatanga river Y1 - 2015 U6 - https://doi.org/10.1016/j.revpalbo.2015.06.008 SN - 0034-6667 SN - 1879-0615 VL - 221 SP - 71 EP - 82 PB - Elsevier CY - Amsterdam ER -