Pollen record from Kleiner Mochowsee, Germany

A Holocene pollen diagram from Kleiner Mochowsee (northern Niederlausitz, East Germany) shows pine as an important constituent of the woodland south of the Schwielochsee. Oak woodland was widespread since the Atlantic. Betula lost its importance at the end of the Preboreal. Fagus is represented continuously in the pollen record since the Atlantic, Carpinus since the Subboreal. However, the two latter tree species remain without great importance throughout the whole pollen record. The poor sandy soils are furthermore reflected by the low values of Corylus during the Boreal, comparable to other records from Berlin and its surrounding area. The 'classical' elm decline could be shown for the Niederlausitz, radiocarbon dates assume a contemporaneous age for this event with other records from northern Germany. Only small-scaled human impact is indicated in prehistoric times, during the migration period it seems to have ceased completely. Later, in the Medieval, deforestation and tillage can be shown. Secale was cultivated since the early Medieval; an accompanying weed flora appeared at the same time. Cultivation of Fagopyrum and Linum usitatissimum could be shown for the late Medieval times.

Pollen analysis from Fiekers Busch, Rinteln, Germany

Fiekers Busch is a wet alder wood close to Rinteln (southwest of Hannover/West Germany) existing there since about 6 000 or - at the most - 7 500 radiocarbon years. The sandy layers below the peaty sequence date from about 9 000 BP. The pollen diagram shows the basic trends of the postglacial vegetational development. Low pollen frequency and poor pollen preservation do , however, strongly restrict the possibilities to explain the peculiarities of the pollendiagram, especially the high pine and linden values.

Pollen record and age determination of a sediment profile from Frengstadsetra, Norway

Innerdalen was once a mountain valley (ca. 780 m a.s.l.) with birch forests, bogs and several summer farms. Today it is a 6.5 km**2 artifical lake. In 1980 and 1981 archaeological and palynological investigations were carried out due to the hydroelectric power plans. Radiocarbon dated pollen diagrams from 9 different localities in Innerdalen provide information on a mountain environment which has been exploited to varying degrees by human groups for thousands of years. In the Birch Zone, ca. 9500-8500 years B.P., the deglaciated surface is vegetated by the normal sequence of pioneering species, first show-bed communities, then shrub/dwarf-shrub communities, and finally a birch forest community. In the Pine Zone, ca. 8500-7500 years B.P., the mixed Birch-Pine forest which prevailed at the end of the Birch Zone is replaced by a dense pine forest. The tree limit was higher than it is today. In the Alder Zone, ca. 7500-4000 years B.P., the newly arrived alder gradually succeeded pine, particularily on good soils. This alder forest has a modem analog in the pre-alpine gray alder forests in Norway. In the last part of the Alder Zone, ca. 6000-4000 years B.P., elm and hazel are nominally present on particularily rich soils, marking the edaphic and climatic optimum in Innerdalen. During this time the first evidence of human impact on the vegetation is apparent in the pollen diagrams. At both Sætersetra in the south of the valley and Liabekken in the north, forest clearance and the development of grazed grass meadows is documented, and human impact continues until the present. The Herb Zone, ca. 4000 years B.P. to 1600 A.D., is characterized by the rapid decline of alder. The forest is increasingly open, and bog formation is initiated. The sub-alpine belt of birch forest is established, probably due to the shift to a cooler, moister climate. Human activity can also have influenced the vegetational changes, although at 4 of the localities human activity also is first apparent after the alder decline. Some localities show measurably less human impact on the vegetation ca. 2600-2000 years B.P. Grazing intensity increases ca. 2000 years B.P. At the end of the Herb Zone rye and barley pollen is registered at Sætersetra and Flonan, indicating contact between the grazing activities of Innerdal and grain cultivation activities outside the valley. The Spruce Zone, ca. 1600 A.D. to the present, does not begin synchronously since the presence of long-distance transported spruce pollen at a locality is entirely dependent on the density of the vegetation ie. degree of human impact. The youngest spruce rise is ca. 1500 A.D. at Røstvangen, when summerfarming is initiated. Summerfarming activities in Innerdal produce an increasingly open landscape. Rye and barley pollen at several localities may indicate limited local cultivation, but is more likely long-distance transport via humans and domesticated animals from cultivated areas outside Innerdalen.

A new modern analogue reference dataset and its application to the 430-kyr pollen record from Lake Biwa

This study presents a newly compiled dataset of modern pollen and climate data from 798 sites across Japan and the Russian Far East. This comprehensive reference dataset combined with the modern analogue technique (MAT) provides a powerful tool for pollen-based reconstruction of the Quaternary Northwest Pacific climate. Pollen-derived reconstruction of the modern climate at the reference pollen-sampling sites matches well with the estimated modern climate values (R2 values vary between 0.79 and 0.95, and RMSEP values vary between 5.8 and 9.7% of the modern climatic range for all nine tested variables). The successful testing of the method encourages its application to the fossil pollen records. We used a coarse-resolution pollen record from Lake Biwa to reconstruct glacial-interglacial climate dynamics in central Japan since ~438 kyr and compared it to the earlier reconstruction based on a less representative reference dataset. The current and earlier results consistently demonstrate that the coldest glacial intervals experienced pronounced cooling in winter and moderate cooling in summer, supporting the growth of cool mixed forest (COMX) where warm mixed forest (WAMX) predominates today. During the last glacial, maximum (~24 kyr BP) mean temperatures of the coldest (MTCO) and warmest (MTWA) month were about -13 °C (RMSEP = 2.34 °C) and 21 °C (RMSEP = 1.66 °C) respectively, and annual precipitation (PANN) was about 800 mm (RMSEP = 158.06 mm). During the thermal optimums of the interglacial intervals, the temperatures of the coldest and warmest month were above 0 °C and 25 °C respectively, leading to the reconstruction of WAMX and temperate conifer forest (TECO). Although both these vegetation types grow in the southern part of Japan today, WAMX requires warmer space. The presence of WAMX during marine isotope stages (MIS) 11 and 1, and its absence during MIS 9 and MIS 5 contradict the marine isotope and Antarctic ice records, suggesting that the latter two interglacials were the warmest of the last 800 kyr. The apparent contradiction allows at least three different explanations including low temporal resolution of the pollen record; different trends in CO2 concentrations during 'short' and 'long' interglacials; and regional climate variability and non-linear response of different regions to the global forcing. More definitive conclusions will be possible on the basis of forthcoming high-resolution pollen records from central Japan.

Pollen records from two outcrop profiles in the Kakitu Mountain of Tibet

There is a great similarity between pollen types which occur in the early Holocene NE Tibetan pollen spectra and those which are commonly considered to be typical for the Würm Late Glacial period in Central Europe and for the Würm Pleniglacial period in Southern Europe. Evidently, this similarity is due to a remarkable general conformity of plant taxa growing in cold-arid regions of the northern hemisphere. The improvement of the climate and the retreat of the glaciers that commenced at the end of the Würm period had already terminated definitely before 9500 BP. In addition, the climatic situation as well as the vegetation belts must have remained rather constant during the following 3000 yr, i.e. through most parts of the climatic optimum of the Holocene.

Pollen record and age determination of a sediment profile from Schmiechener See, Germany

Die untersuchten Schluffe und Kiese sind unter kaltzeitlichen Bedingungen in einem See mit Schwimmpflanzengesellschaften abgelagert worden. Zur Sedimentationszeit gab es in der Umgebung des Sees eine tundrenartige Vegetation, die auch Steppenarten enthielt.

Palynology on a profile from the Krusné Hory Mountains

Site details: The raised bog Fláje-Kiefern (50°429N, 13°329 E; 760 m a.s.l.; size ca. 500x500 m) lies in the Krusné Hory Mountains (Erzgebirge), Czech Republic, about 10 km from Georgenfelder Moor in Germany. Hejny and Slavík (1988) described the phytogeographic region of the Krusne Hory Mountains as 'a region of mountain flora and vegetation, with thermophilous species largely missing. In the natural forests, conifers, especially spruce (Picea excelsa) prevail. The deforested areas have been converted into meadows and pastures'. The climate is cool with annual average temperatures of about 5°C and annual precipitation of about 900 mm. The bedrock is Precambrian crystallinicum.

Pollen record and dating of a sediment profile from Ahlequellmoor in Germany

A pollen diagram from the Ahlequellmoor in the Solling area shows the history of vegetation and settlement over the last 7,800 years. In the early Atlantic period mixed deciduous forest with mainly Tilia together with Ulmus and Quercus grew in the area. In the late Atlantic period Quercus became most abundant. Fagus spread in the Sub-boreal period at about 2700 B.C. Since ca. 900 B.C. the Solling was covered by beech forests with some oak. In prehistoric times woodland grazing is indicated. Only in Medieval times are two settlements in the vicinity of the Ahlequellmoor reflected in the pollen diagram. The earlier one is dated to about A.D. 750-1020, and may be connected with the former Monastery of Hethis, which is thought to have existed close to the fen from A.D. 815 to 822. The second Medieval settlement dates to the 11th-12th century. The large-scale woodland destruction of late Medieval and modern times is not clearly visible. The silvicultural measures of the last 200 years are reflected by increasing values of spruce and grassland taxa.

Profiles of diatoms, pollen, XRD, XRF and organic composition of two sediment cores (PG2022 and PG2023) from Lake Kyutyunda in Yakutia, NE Siberia, Russia

Although the climate development over the Holocene in the Northern Hemisphere is well known, palaeolimnological climate reconstructions reveal spatiotemporal variability in northern Eurasia. Here we present a multi-proxy study from north-eastern Siberia combining sediment geochemistry, and diatom and pollen data from lake-sediment cores covering the last 38,000 cal. years. Our results show major changes in pyrite content and fragilarioid diatom species distributions, indicating prolonged seasonal lake-ice cover between ~13,500 and ~8,900 cal. years BP and possibly during the 8,200 cal. years BP cold event. A pollen-based climate reconstruction generated a mean July temperature of 17.8°C during the Holocene Thermal Maximum (HTM) between ~8,900 and ~4,500 cal. years BP. Naviculoid diatoms appear in the late Holocene indicating a shortening of the seasonal ice cover that continues today. Our results reveal a strong correlation between the applied terrestrial and aquatic indicators and natural seasonal climate dynamics in the Holocene. Planktonic diatoms show a strong response to changes in the lake ecosystem due to recent climate warming in the Anthropocene. We assess other palaeolimnological studies to infer the spatiotemporal pattern of the HTM and affirm that the timing of its onset, a difference of up to 3,000 years from north to south, can be well explained by climatic teleconnections. The westerlies brought cold air to this part of Siberia until the Laurentide ice-sheet vanished 7,000 years ago. The apparent delayed ending of the HTM in the central Siberian record can be ascribed to the exceedance of ecological thresholds trailing behind increases in winter temperatures and decreases in contrast in insolation between seasons during the mid to late Holocene as well as lacking differentiation between summer and winter trends in paleolimnological reconstructions.

Pollen record of sediment profile NERO from Russia

(of book) Problems of origin of the hydrosphere, history of formation and development of underground water, of the World Ocean, lakes, rivers, surface and subsurface ice are under consideration in the book. An attempt of the complete reconstruction of the continental hydrosphere in the Eastern Europe in Late Pleistocene is made. Methods of paleohydrologic studies are described. Some papers are devoted to paleoclimatic problems of river runoff formation and paleotermic evolution of continental glaciers.

XRF scanning, pollen and spores of ODP Site 108-659

Pliocene vegetation dynamics and climate variability in West Africa have been investigated through pollen and XRF-scanning records obtained from sediment cores of ODP Site 659 (18°N, 21°W). The comparison between total pollen accumulation rates and Ti/Ca ratios, which is strongly correlated with the dust input at the site, showed elevated aeolian transport of pollen during dusty periods. Comparison of the pollen records of ODP Site 659 and the nearby Site 658 resulted in a robust reconstruction of West African vegetation change since the Late Pliocene. Between 3.6 and 3.0 Ma the savannah in West Africa differed in composition from its modern counterpart and was richer in Asteraceae, in particular of the Tribus Cichorieae. Between 3.24 and 3.20 Ma a stable wet period is inferred from the Fe/K ratios, which could stand for a narrower and better specified mid-Pliocene (mid-Piacenzian) warm time slice. The northward extension of woodland and savannah, albeit fluctuating, was generally greater in the Pliocene. NE trade wind vigour increased intermittently around 2.7 and 2.6 Ma, and more or less permanently since 2.5 Ma, as inferred from increased pollen concentrations of trade wind indicators (Ephedra, Artemisia, Pinus). Our findings link the NE trade wind development with the intensification of the Northern Hemisphere glaciations (iNHG). Prior to the iNHG, little or no systematic relation could be found between sea surface temperatures of the North Atlantic with aridity and dust in West Africa.