Description: Reading the sediment record in terms of past climates is challenging since linking climate change to the associated responses of sedimentary systems is not always straightforward. Here we analyze the erosional response of landscapes on the Tibetan Plateau to interglacial climate forcing. Using the theory of dynamical systems on Holocene time series of geochemical proxies, we derive a sedimentary response model that accurately simulates observed proxy variation in three lake records. The model suggests that millennial variations in sediment composition reflect a self‐organization of landscapes in response to abrupt climate change between 11.6 and 11.9 ka BP. The self‐organization is characterized by oscillations in sediment supply emerging from a feedback between physical and chemical erosion processes, with estimated response times between 3,000 to 18,000 years depending on catchment topography. The implications of our findings emphasize the need for landscape response models to decipher the paleoclimatic code in continental sediment records.

Description: Ice-rich permafrost deposits and their isotopic composition were studied at four sites in the western foreland of the Verkhoyansk Mountains, Central Yakutia. The isotopic composition of ice wedges formed in alluvial and loess-like sediments generally reflects the palaeoclimate of winter conditions. The middle Weichselian Ice Complex developed around 41 ka 14C BP during a period with colder winters than today. Similarly severe conditions are reflected in the late Weichselian Ice Complex from around 20 ka to 13 ka 14C BP. The transition to the Holocene is characterised by increases of 5‰ and 35‰ in δ18O and δD, respectively. This warming is documented in wedge ice, which grew between 8.5 and 4.5 ka BP. Towards the late Holocene and sub-recent times, a climatic deterioration is recorded, reflected by lighter isotopic composition of ice wedges, which developed between 1.2 ka and 0.7 ka 14C BP.

Description: A pollen record, obtained from sediments of Lake Sokoch in mountain interior of the Kamchatka Peninsula, covers the last ca. 9600. years (all ages are given in calibrated years BP). Variations in local components, including pollen, spores and non-pollen palynomorphs, and related changes in sedimentation document the lake development from initially seepage and shallow basin to deeper lake during the mid Holocene and then to the hydrologically open system during the late Holocene. The studies of volcanic ashes from the lake sediment core show their complex depositional histories.Lake Sokoch occupies a former proglacial basin between two terminal moraines of the LGM time. The undated basal part of record before ca. 9600. year BP, however, does not reflect properly cold conditions. At that time, although shrublands and tundra dominated, stone birch and white birch forests have already settled in surroundings; the presence of alder woodland indicates wet and maritime-like climate. The subsequent forest advance suggesting warmer conditions was interrupted by the ca. 8000-7600. year BP spell of cooler climate. The following culmination of warmth is bracketed by the evidence of the first maximal forest extent between ca. 7400 and 5100. year BP. During that time, dramatic retreat of alder forest suggests a turn from maritime-like to more continental climate conditions. The cool and wet pulse after ca. 5100. year BP was pronounced as forests retreat while shrublands, meadows and bogs extended. An expansion of white birch forest since ca. 3500. year BP reflected the onset of drier climate, strengthening continentality and seasonal contrast. The second maximum of forests dominated by both stone and white birches occurred between ca. 2200 and 1700. year BP and indicated warming in association with relatively dry and increasingly continental climate. The following period was wetter and cooler, and minor outbreak of alder forest around ca. 1500. year BP suggests a short-term return of maritime-like conditions. Since ca. 1300. year BP forests retreated and replaced by shrublands, tundra and bogs, pointing to cool and wet climate and likely increased back continentality. A prominent re-advance of stone birch forest shown atop the record, most probably reflects recent warming trend.The reconstructed cool periods correlate well with Holocene glacial advances in neighboring mountain areas and with the tree ring and ice core records from the Central Kamchatka Depression. The Lake Sokoch pollen record, being consistent with the previously obtained regional paleoclimatic data, yet contributes new detailed information, especially for the late Holocene.

Description: The northeastern part of Eurasia represents one of Earth‟s most extreme periglacial climate regions, characterized by the strongest seasonal temperature amplitudes on the northern hemisphere. The region is occupied by deep-reaching permafrost and covered by widespread taiga and tundra vegetation (Müller et al., 2010). Paleoenvironmental studies have been conducted close to the northern polar cycle in the Verkhoyansk Mountain Range and its western foreland to infer periglacial landscape dynamics in response to late Quaternary climate change. The distribution of preserved terminal moraines reveal several mountain glacier advances in the past (Stauch and Lehmkuhl, 2010). According to luminescence dating, the widest geologically documented glacial advence took place during the Saalian stage around 135 ka. Less extended glaciations to the foreland appeared during the early Weichselian at 100-120 ka and at 85-90 ka, while the youngest glaciation (〉50 ka) was confined to the mountain area. No regional glacial advance is evident for the late Weichselian and the last glacial maximum, a time which was characterized by aeolian loess formation (Stauch et al., 2007, Popp et al., 2007). Sediment cores from the 25 m deep Lake Billyakh (340 m a.s.l.), a former proglacial basin, document environmental changes of the last 50 kyr (Diekmann et al., 2007). Pollen records indicate a dry climate for the late Weichselian, indicated by a change from tundra towards cold steppe vegetation after 32 ka until 13.5 ka BP (Müller et al., 2009, 2010). For the same time, sedimentological and diatom data indicate a lake level drop. Modelling experiments with a general circulation model suggest that the consecutive decline in the extent of mountain glaciers and increase in dryness through the Weichselian was dictated by the growing shielding effect of the western Eurasian ice sheets that prevented the supply of moist Atlantic air masses to eastern Siberia (Krinner et al., 2011). In addition, enhanced deposition of dust reduced the albedo and promoted ice and snow melting during summer (Krinner et al., 2011). Environmental changes towards interglacial conditions of the Holocene are documented in the Lake Billyakh deposits (Müller et al., 2009) as well as in a peat section at Dyanushka River (Werner et al., 2009). Both records show that climate amelioration started after 13.5 ka BP with the quick return of larch trees that also persisted during the Younger Dryas cold spell, suggesting that the Verkhoyansk Mountain area possibly represented a plant refugium during the climate extremes of the last ice age (Tarasov et al., 2009). Reforestation continued since 11.4 ka BP with the spread of boreal cold deciduous and taiga forests and reached a maximum extent after 7 ka BP. Limnological conditions of Lake Billyakh changed to a higher lake-level and increased biological productivity consistent with climate warming and increased humidity. Mean July air temperatures reconstructed by fossil aquatic chironomids, using a regional inference model (Nazarova et al., 2011), indicate warmest summer temperatures between roughly 9.0 and 6.6 ka BP. The stable-isotope composition of ice wedges in permafrost soils point to warmer winters during the early Holocene compared to the late Holocene (Popp et al, 2006). The recognition of a regional early Holocene climate optimum is consistent with long-term Holocene climate development in wide parts of northern Eurasia. References Diekmann, B., Andreev, A.A., Müller, G., Lüpfert, H., Pestryakova, L., Subetto, D., 2007. Expedition 'Verkhoyansk 2005' - Limnogeological studies at Lake Billyakh, Verkhoyansk Mountains, Yakutia. In: Schirrmeister, L. (ed.): Expeditions in Sibiria in 2005, Reports on Polar and Marine Research, 550: 247-258. Krinner, G., Diekmann, B., Colleoni, F., Stauch, G., 2011. Global, regional and local scale factors determining glaciation. Quaternary Science Reviews, 30: 821-831. Müller, S., Tarasov, P. E., Andreev, A., Diekmann, B., 2009. Late Glacial to Holocene environments in the present-day coldest region of the Northern Hemisphere inferred from a pollen record of Lake Billyakh, Verkhoyansk Mts ., NE Siberia. Climate of the Past 5: 73-84. Müller, S., Tarasov, P.E., Andreev, A.A., Tuetken, T., Gartz, S., Diekmann, B., 2010. Late Quaternary vegetation and environments in the Verkhoyansk Mountains region (NE Asia) reconstructed from a 50-kyr fossil pollen record from Lake Billyakh. Quaternary Science Reviews, 29: 2071-2086. Nazarova, L., Herzschuh, U., Wetterich, S., Kumke, T., Pestryakova, L., 2011. Chironomid-based inference models for estimating mean July air temperature and water depth from lakes in Yakutia, northeastern Russia. Journal of Paleolimnology, 45(1): 57-71. Popp, S., Belolyubsky, I., Lehmkuhl, F., Prokopiev, A., Siegert, C., Spektor, V., Stauch, G., Diekmann, B. (2007): Sediment provenance of late Quaternary morainic, fluvial and loess-like deposits in the southwestern Verkhoyansk Mountains (eastern Siberia) and implications for regional palaeoenvironmental reconstructions. Geological Journal, 42: 477-497. Popp, S., Diekmann, B., Meyer, H., Siegert, C., Syromyatnikov, I., Hubberten, H. W., 2006. Palaeoclimate signals as inferred from stable-isotope composition of ground ice in the Verkhoyansk foreland, Central Yakutia. Permafrost and Periglacial Processes, 17: 119-132. Stauch, G., Lehmkuhl, F., 2010. Quaternary glaciations in the Verkhoyansk Mountains, Northeast Siberia. Quaternary Research, 74: 145-155. Stauch, G., Lehmkuhl, F., Frechen, M., 2007. Luminescence chronology from the Verkhoyansk Mountains (North-Eastern Siberia). Quaternary Geochronology, 2: 255-259. Tarasov, P., Müller, S., Andreev, A., Werner, K., Diekmann, B., 2009. Younger Dryas Larix in eastern Siberia: A migrant or survivor? PAGES News, 17(3): 122-123. Werner, K., Tarasov, P.E., Andreev, A.A., Müller, S., Kienast, F., Zech, M., Zech, W., Diekmann, B., 2009. A 12.5-kyr history of vegetation dynamics and mire development with evidence of Younger Dryas larch presence in the Verkhoyansk Mountains, East Siberia, Russia. Boreas, 39(1): 56-68.

Description: Fossil diatom assemblages in a sediment core from a small lake in Central Kamchatka (Russia) were used to reconstruct palaeoenvironmental conditions of the late Holocene. The waterbody may be a kettle lake that formed on a moraine of the Two-Yurts Lake Valley, located on the eastern slope of the Central Kamchatka Mountain Chain. At present, it is a seepage lake with no surficial outflow. Fossil diatom assemblages show an almost constant ratio between planktonic and periphytic forms throughout the record. Downcore variations in the relative abundances of diatom species enabled division of the core into four diatom assemblage zones, mainly related to changes in abundances of Aulacoseira subarctica, Stephanodiscus minutulus, and Discostella pseudostelligera and several benthic species. Associated variations in the composition and content of organic matter are consistent with the diatom stratigraphy. The oldest recovered sediments date to about 3220 BC. They lie below a sedimentation hiatus and likely include reworked deposits from nearby Two-Yurts Lake. The initial lake stage between 870 and 400 BC was characterized by acidic shallow-water conditions. Between 400 BC and AD 1400, lacustrine conditions were established, with highest contributions from planktonic diatoms. The interval between AD 1400 and 1900 might reflect summer cooling during the Little Ice Age, indicated by diatoms that prefer strong turbulence, nutrient recycling and cooler summer conditions. The timing of palaeolimnological changes generally fits the pattern of neoglacial cooling during the late Holocene on Kamchatka and in the neighbouring Sea of Okhotsk, mainly driven by the prevailing modes of regional atmospheric circulation.