The younger dryas cooling in northeast Germany: summer temperature and environmental changes in the Friedländer Groβe Wiese region

Abstract

A lake sediment record from the Friedländer Groβe Wiese in northeast Germany was studied to reconstruct summer temperature changes associated with changes in vegetation development during the Weichselian Lateglacial. The record was analysed for pollen, chironomids, and oxygen and carbon isotopes of lake marl. The combination of radiocarbon dates, the presence of the Laacher See Tephra and correlation of lithological and palynological changes with other records from the region indicated that the record encompassed the Allerød to the early Holocene. Pollen assemblages reflect development of birch and later pine‐dominated forests during the Allerød, comparable to other sites in the region. Chironomid‐inferred mean July air temperatures (C‐IT) for this period range between ∼14.0 and 14.8°C. A temporary decrease in C‐IT of ∼1°C, a negative shift in the isotope records, and a minor decline of birch may correspond to Greenland Interstadial 1b. Even though the transition to the Younger Dryas appears to be affected by reworking and redeposition processes, a drop in C‐IT to ∼11.1°C is reconstructed for the later part of the Younger Dryas, while it appears that pine locally persisted in the region. Comparison with a nearby pollen record further indicates a local expansion of wetland grasses during this period. At the transition to the Holocene, C‐IT increased to ∼15.7°C, while birch and pine forests re‐expanded. Copyright © 2012 John Wiley & Sons, Ltd.

To what extent did changes in July temperature influence Lateglacial vegetation patterns in NW Europe?

“…When the chironomid-based temperatures or pollen ; L ¼ Lusvatnet (Aarnes et al, 2012;Birks et al, 2014); K ¼ Kråkenes Brooks and Birks, 2000); AF ¼ Abernethy Forest (Birks and Mathewes, 1978;Brooks et al, 2012); WB ¼ Whitrig Bog (Mayle et al, 1997;Brooks and Birks, 2000); A ¼ Loch Ashik (Walker et al, 1988;Brooks et al, 2012); HW ¼ Hawes Water (Walker, 1955;Smith, 1958;Oldfield, 1960;Pennington, 1977;Bedford et al, 2004); Q ¼ Quidenham Mere (Hunt and Birks, 1982;Jeffers et al, 2012a); N ¼ Lough Nadourcan (Watts, 1977;Watson et al, 2010;Jeffers et al, 2012b); F ¼ Fiddaun (Van Asch et al, 2012b;Van Asch and Hoek, 2012;H ¼ Hijkermeer (Heiri et al, 2007); KV ¼ Klein Ven (Van Asch et al, 2013); FGW ¼ Friedl€ ander Grobe Wiese (Van Asch et al, 2012a); Ech ¼ Ech (Millet et al, 2012); LR ¼ Laguna de la Roya (Muñoz Sobrino et al, 2013). E ¼ Lochan an Druim, Eriboll (Birks, 1984), S ¼ Slotseng (Mortensen et al, 2011); B ¼ Bjørker€ ods mosse and 2 other sites (Liedberg J€ onsson, 1988); U ¼ Usselo (Van Geel et al, 1989); DB ¼ De Borchert (Van Geel et al, 1981). percentages are highly variable during an interval we have also indicated this.…”

“…Birch woodland was sparse in Ireland (Watts, 1977;Van Asch and Hoek, 2012), even though summer temperatures were suitable for tree growth. Explanatory hypotheses propose the importance of other limiting climate variables such as a lack of precipitation, exposure to strong cold winds, late-spring frosts, dry soils, and grazing (Atkinson, 1992) by herbivores such as Giant Irish Deer and Reindeer (Watts, 1977;Van Asch and Hoek, 2012) Birch seedlings are destroyed by persistent grazing (Atkinson, 1992).…”

Palaeoenvironmental Proxies for Permafrost Presence During the Younger Dryas, Central Poland

“…In the European lowlands, between~55 and 50°N, mean annual air temperatures in the Younger Dryas probably ranged from À8 to À1°C, temperatures of the coldest month from À25 to À15°C and those of the warmest month from 11 to 14°C (Isarin, 1997;Isarin et al, 1998;van Asch et al, 2012). Climatic simulations suggest that cooling was more severe near the Atlantic Ocean than in central Europe.…”

Multiproxy-Untersuchungen zur Paläoökologie und -hydrologie eines spätglazial- bis frühholozänen Flachsees im nordostdeutschen Küstengebiet (Glowe-Paläosee/Insel Rügen)

“…Im Unterschied dazu herrscht in großflächigen Sandgebieten, z. B. im Bereich des Haffstausees (Bramer 1975, de Klerk 2004, Lampe et al 2011, van Asch et al 2012) sowie seiner Abflüsse im Raum Friedland und Demmin (Janke 1978), zeitweise die Kiefer mit über 75 % Pollenanteil vor.…”