TY - THES A1 - Melles, Martin T1 - Rekonstruktion der spätquartären Entwicklungsgeschichte polarer Küstenregionen mit Hilfe von Seesedimenten Y1 - 1999 ER - TY - JOUR A1 - von Hippel, Barbara A1 - Stoof-Leichsenring, Kathleen R. A1 - Schulte, Luise A1 - Seeber, Peter Andreas A1 - Epp, Laura Saskia A1 - Biskaborn, Boris A1 - Diekmann, Bernhard A1 - Melles, Martin A1 - Pestryakova, Luidmila Agafyevna A1 - Herzschuh, Ulrike T1 - Long-term funguseplant covariation from multi-site sedimentary ancient DNA metabarcoding JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - Climate change has a major impact on arctic and boreal terrestrial ecosystems as warming leads to northward treeline shifts, inducing consequences for heterotrophic organisms associated with the plant taxa. To unravel ecological dependencies, we address how long-term climatic changes have shaped the co-occurrence of plants and fungi across selected sites in Siberia. We investigated sedimentary ancient DNA from five lakes spanning the last 47,000 years, using the ITS1 marker for fungi and the chloroplast P6 loop marker for vegetation metabarcoding. We obtained 706 unique fungal operational taxonomic units (OTUs) and 243 taxa for the plants. We show higher OTU numbers in dry forest tundra as well as boreal forests compared to wet southern tundra. The most abundant fungal taxa in our dataset are Pseudeurotiaceae, Mortierella, Sordariomyceta, Exophiala, Oidiodendron, Protoventuria, Candida vartiovaarae, Pseudeurotium, Gryganskiella fimbricystis, and Tricho-sporiella cerebriformis. The overall fungal composition is explained by the plant composition as revealed by redundancy analysis. The fungal functional groups show antagonistic relationships in their climate susceptibility. The advance of woody taxa in response to past warming led to an increase in the abun-dance of mycorrhizae, lichens, and parasites, while yeast and saprotroph distribution declined. We also show co-occurrences between Salicaceae, Larix, and Alnus and their associated pathogens and detect higher mycorrhizal fungus diversity with the presence of Pinaceae. Under future warming, we can expect feedbacks between fungus composition and plant diversity changes which will affect forest advance, species diversity, and ecosystem stability in arctic regions. KW - Ecosystem dynamics KW - Fungus -plant covariation KW - ITS marker KW - Metabarcoding KW - Sedimentary ancient DNA KW - Siberia KW - trnL P6 loop Y1 - 2022 U6 - https://doi.org/10.1016/j.quascirev.2022.107758 SN - 0277-3791 SN - 1873-457X VL - 295 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Herzschuh, Ulrike A1 - Birks, H. John B. A1 - Laepple, Thomas A1 - Andreev, Andrei A1 - Melles, Martin A1 - Brigham-Grette, Julie T1 - Glacial legacies on interglacial vegetation at the Pliocene-Pleistocene transition in NE Asia JF - Nature Communications N2 - Broad-scale climate control of vegetation is widely assumed. Vegetation-climate lags are generally thought to have lasted no more than a few centuries. Here our palaeoecological study challenges this concept over glacial–interglacial timescales. Through multivariate analyses of pollen assemblages from Lake El’gygytgyn, Russian Far East and other data we show that interglacial vegetation during the Plio-Pleistocene transition mainly reflects conditions of the preceding glacial instead of contemporary interglacial climate. Vegetation–climate disequilibrium may persist for several millennia, related to the combined effects of permafrost persistence, distant glacial refugia and fire. In contrast, no effects from the preceding interglacial on glacial vegetation are detected. We propose that disequilibrium was stronger during the Plio-Pleistocene transition than during the Mid-Pliocene Warm Period when, in addition to climate, herbivory was important. By analogy to the past, we suggest today’s widespread larch ecosystem on permafrost is not in climate equilibrium. Vegetation-based reconstructions of interglacial climates used to assess atmospheric CO2–temperature relationships may thus yield misleading simulations of past global climate sensitivity. Y1 - 2016 U6 - https://doi.org/10.1038/ncomms11967 SN - 2041-1723 VL - 7 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Andreev, Andrei A1 - Nazarova, Larisa B. A1 - Lenz, Marlene M. A1 - Böhmer, Thomas A1 - Syrykh, Ludmila A1 - Wagner, Bernd A1 - Melles, Martin A1 - Pestryakova, Luidmila A. A1 - Herzschuh, Ulrike T1 - Late Quaternary paleoenvironmental reconstructions from sediments of Lake Emanda (Verkhoyansk Mountains, East Siberia) JF - Journal of quaternary science : JQS N2 - Continuous pollen and chironomid records from Lake Emanda (65 degrees 17'N, 135 degrees 45'E) provide new insights into the Late Quaternary environmental history of the Yana Highlands (Yakutia). Larch forest with shrubs (alders, pines, birches) dominated during the deposition of the lowermost sediments suggesting its Early Weichselian [Marine Isotope Stage (MIS) 5] age. Pollen- and chironomid-based climate reconstructions suggest July temperatures (T-July) slightly lower than modern. Gradually increasing amounts of herb pollen and cold stenotherm chironomid head capsules reflect cooler and drier environments, probably during the termination of MIS 5. T-July dropped to 8 degrees C. Mostly treeless vegetation is reconstructed during MIS 3. Tundra and steppe communities dominated during MIS 2. Shrubs became common after similar to 14.5 ka BP but herb-dominated habitats remained until the onset of the Holocene. Larch forests with shrub alder and dwarf birch dominated after the Holocene onset, ca. 11.7 ka BP. Decreasing amounts of shrub pollen during the Lateglacial are assigned to the Older Dryas and Younger Dryas with T-July similar to 7.5 degrees C. T-July increased up to 13 degrees C. Shrub stone pine was present after similar to 7.5 ka BP. The vegetation has been similar to modern since ca. 5.8 ka BP. Chironomid diversity and concentration in the sediments increased towards the present day, indicating the development of richer hydrobiological communities in response to the Holocene thermal maximum. KW - chironomids KW - environmental reconstructions KW - Late Quaternary KW - pollen Y1 - 2022 U6 - https://doi.org/10.1002/jqs.3419 SN - 0267-8179 SN - 1099-1417 VL - 37 IS - 5 SP - 884 EP - 899 PB - Wiley CY - New York, NY [u.a.] ER -