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Owing to long-term similarities with regard to orbital climate forcing (i.e., low eccentricity and a dampened influence of precession), Marine Isotope Stage (MIS) 11 represents one of the closest astronomical analogues for present and future climate. Hence, insights into the climate variability of MIS 11 can contribute to a better understanding of the climatic evolution of the present (Holocene) interglacial as it would occur without human interference. In order to elucidate the natural climate variability during MIS 11, this study examines predominantly annually laminated lake sediments of Holsteinian age from Dethlingen, northern Germany. The Holsteinian interglacial is widely accepted to be the terrestrial equivalent of MIS 11c in central Europe and can be biostratigraphically correlated with the Hoxnian, Mazovian and Praclaux interglacials on the British Isles, in Poland and in France, respectively. These correlations yield the potential to cross-check the results from individual sites on a regional scale. This study is based on a multi-proxy approach including palynological, micropaleontological, sedimentological, geochemical and time series analyses within a wellconstrained chronological framework that has been established through varve counting and regional bio-stratigraphic correlations with other annually laminated archives of Holsteinian age. In particular, the here-presented study aims at (i) fingerprinting the long-term (centennial- to millennial-scale) and short-term (sub-decadal- to decadal-scale) climate variability during the Holsteinian interglacial, (ii) deciphering the nature, tempo and trigger mechanisms of abrupt climate change under interglacial boundary conditions, and (iii) assessing its impact on terrestrial ecosystems. With regard to long-term climate variability, the vegetation succession at Dethlingen as inferred from pollen data provides insights into the mesocratic to telocratic forest phases of a glacial-interglacial cycle spanning ~11500 (± 1000) years of the 15-16-ka-long Holsteinian interglacial. The development of temperate mixed forests suggests a general prevalence of mild climatic conditions during the Holsteinian. The older parts of the interglacial are characterised by the strong presence of boreal tree taxa (e.g., Picea), whereas the younger parts of the interglacial are marked by the expansion of sub-Atlantic to Atlantic forest elements (e.g., Abies, Buxus, Ilex, Quercus) and the decline of boreal tree taxa. This vegetation succession suggests a general warming trend and decreasing seasonality over the course of the Holsteinian interglacial. Based on the maximum pollen abundances of indicator tree taxa (e.g., Buxus and Quercus), peak warmth was reached during the later stages of the interglacial; it was accompanied by high humidity. The forest succession of the Holsteinian interglacial was punctuated by abrupt and gradual changes in the abundances of temperate plant taxa. These vegetation changes indicate considerable intra-interglacial climate variability. In particular, two marked declines of temperate taxa leading to the transient development of boreal and sub-boreal forests were triggered by centennial-scale climate oscillations, here termed Older and Younger Holsteinian Oscillations (OHO and YHO). These oscillations occurred ~6000 and ~9000 years after the onset of the interglacial pioneer forestation in central Europe, respectively. To assess the impact of abrupt climate change on terrestrial ecosystems during the Holsteinian and to investigate the underlying driving mechanisms, the intervals spanning the OHO and the YHO at Dethlingen were subjected to decadal-scale palynological and sedimentological analyses. Based on these data, the OHO comprises a 90-year-long decline of temperate taxa associated with expansion of Pinus and non-arboreal pollen, and a subsequent 130-year-long recovery of temperate taxa marked by the pioneer expansion of Betula and Alnus. Owing to its highly characteristic imprint on vegetation dynamics, the OHO can be identified in pollen records from the central European lowlands north of 50º latitude, from the British Isles to Poland. A close inspection of individual pollen records from that region reveals the prevalence of colder winters during the OHO, with a gradient of decreasing temperature and moisture availability, and increased continentality towards eastern Europe. This climate pattern points to a weakened influence of the westerlies and/or stronger influence of the Siberian High connected to the OHO. The vegetation dynamics during the YHO are characterised by a decline of temperate taxa (particularly of Carpinus) and the expansion of pioneer trees (mainly Betula). In contrast to the OHO, frost-sensitive taxa (e.g., Ilex, Buxus and Hedera) continued to thrive. This suggests that mean winter temperatures remained relatively high (>0 ºC) during the YHO pointing to a decrease of summer warmth related to the climatic deterioration. The YHO, which has a duration on the order of 300 years, is centered within a long-term (~1500-year) decline and subsequent, millennial-scale recovery of temperate taxa. Because the impact of the OHO and the YHO on the vegetation at Dethlingen was markedly different, both short-term climate oscillations may have been caused by different trigger mechanisms. For the OHO, the inferred regional-scale winter cooling over central Europe lasting for several decades points to a decrease in ocean heat transport, most likely related to a transient slowdown in North Atlantic Deep Water formation. This view is supported by the strong resemblance of the OHO to the 8.2 ka event of the Holocene with regard to the duration, imprint on terrestrial ecosystems, spatial pattern of the climatic impact, timing within the respective interglacial, and prevailing interglacial boundary conditions. In contrast, the presence of frost-sensitive taxa during the YHO appears to exclude a reduction in oceanic heat transport as postulated for the OHO. Instead, the long-lasting, gradual changes in the abundances of temperate taxa suggest a connection to orbital forcing, with the triggering mechanism causing the centennial-scale vegetation setback itself remaining unclear. The characteristics of short-term climate variability were investigated based on microfacies and time series analyses of a ~3200-year-long, annually laminated window of the Dethlingen record. The annual laminations at Dethlingen comprise biogenic varves consisting of two discrete sub-layers. The light layers, which are controlled by the intensity of diatoms blooms during spring/summer, reflect changes in the productivity of the Dethlingen palaeolake. In contrast, the dark layers, which consist predominantly of amorphous organic matter and fragmented diatom frustules, represent sediment deposition during autumn/winter. Spectral analyses of the thicknesses of the light and dark layers have revealed several peaks exceeding the 95% and 99% confidence levels that are near-identical to those known from modern instrumental data and Holocene records. Decadal-scale signals at periods of 90, 25, and 10.5 years are likely associated with the 88-, 22- and 11-year solar cycles; hence, solar activity appears to have been a forcing agent in productivity changes of the Dethlingen palaeolake. Sub-decadal-scale signals at periods between 3 and 5 years and ~6 years may reflect an influence of the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO) on varve formation during winter.
Forty two samples of the Late Eocene Kiliran oil shale, Central Sumatra Basin, Indonesia were collected from a 102 m long drill core. Palynofacies and geochemical analyses have been carried out to reconstruct the paleoenvironmental conditions and paleoecology during deposition of the oil shale. Amorphous organic matter (AOM) is very abundant (>76%). B. braunii palynomorph is present (3-16%) as the only autochtonous structured organic matter and generally more abundant in middle part of the profile. The stable carbon isotopic composition of organic matter (δ13C) varies from -27.0 to -30.5‰ and is generally more depleted in middle part of the profile. The ratio of total organic carbon to sulfur (TOC/S), used as salinity indicator, ranges from 2.5 to 15.8 and shows variations along the profile. Relatively less saline environments are observed in the middle part profile. Fungal remains are generally present only in middle part of the profile with distinct peak of abundances. The presence of fungal remains is regarded as an indication for a relatively warmer climate during deposition of middle part of the profile. The warmer climate is thought to influence the establishment of a thermocline, limiting the supply of recycled nutrients to the epilimnion. Consequently, the primary productivity in the Kiliran lake decreased during deposition of the middle part of the profile as indicated by the relatively depleted δ13C and the blooming of B. braunii. The chemocline was also shoaling during deposition of the middle part of the profile according to the higher abundance of isorenieratene derivatives of green sulfur bacteria origin. The warmer climate affected also to increase of water supply and thus less saline environments.
Tectonic subsidence is also thought to be a significant factor for the development of the Kiliran lake. The Zr/Rb ratio, an indicator for grain size, ranges from 0.4 to 1.3 and generally increases upwards along the profile. Three sudden decreases of the ratio are observed, indicating rapid change to finer grain size. These decreases are interpreted to indicate rapid deepening events of the lake due to mainly periodic subsidence. During deposition of lower part of the profile, the subsidence rates might have been relatively higher than sediment and water supply rates, resulting in a higher autochtonous fraction in the oil shale. During deposition of middle part of the profile, the sediment and water supply rates were relatively higher promoting distinct progradational sedimentation. Subsequently, the lake became more shallow and smaller during deposition of the upper part of the profile, leading to a relatively higher terrigenous input to the oil shale.
Norneohop-13(18)-ene and neohop-13(18)-ene derived from methanotrophic bacteria are the dominant hopanoid hydrocarbons. The sum of their concentrations varies from 40.6 to 360.0 μg/g TOC. The δ13C of these compounds are extremely depleted (-45.2 to -50.2‰). The occurrence of abundant bacteria including methanotrophic bacteria was responsible for the recycling of carbon below the chemocline of the lake. The effect of the recycling of carbon is observed by the presence of a concomitant depletion (about 7-9‰) in 13C of some specific biomarkers derived from organisms dwelling in the whole phototrophic zone.
4-Methylsterane and 4-methyldiasterene homologues occur in the oil shale as the predominant biomarkers. The sum of the concentrations of all homologues are about 40.3-1,009.2 μg/g TOC with generally higher values in uppermost and lower parts of the profile. Ca accounts as the predominant element in the oil shale, ranging from 5.0 to 16.7%. This element shows generally parallel variation with the 4-methylsterane homologues along the profile. This suggests that the 4-methylsteranes were derived from biological sources favoring more alkaline and more trophic environments. On the other hand, these compounds were less abundant in middle part of the profile which is consistent with less alkaline and less trophic environments promoting B. braunii to bloom.
The 4-methylsterane homologues are considered to originate from Dinoflagellates. Alternation between Dinoflagellates and B. braunii in Paleogene lake systems due to water chemistry changes are known from previous studies. Moreover, freshwater Dinoflagellates have been frequently reported to occur in the basin depocenters. In the present case, distinct alternation between B. braunii abundances and concentrations of 4-methylsterane homologues along the studied oil shale profile suggest that the 4-methylsterane homologues were derived from freshwater Dinoflagellates although dinosterane is not present in the sediment extracts. Water alkalinity and trophic level changes were most likely responsible for the alternation of Dinoflagellates and B. braunii blooming.
Despite mounting evidence of the anthropogenic influence on the Earth's climate, underlying mechanisms of climate change often remain elusive. The investigation of periods of rapid climate change from geological archives may provide crucial information about magnitude, duration, teleconnections of and regional responses to global and hemispheric scale climate perturbations. Thus, paleoclimate reconstructions may help in mitigating and adapting to the challenges of the coming decades. The '8.2 kyr B.P. climatic event' has previously been proposed as a possible analogue for the future climatic scenario of a reduced Atlantic Meridional Overturning Circulation (AMOC). The catastrophic drainage of the Laurentide meltwater lakes through the Hudson Bay and into the Labrador Sea, that occurred ca. 8.47 kyr B.P., caused the slowdown of the AMOC around 8.2 kyr B.P.. Subsequently, reduced heat transfer towards Europe triggered a substantial decline in (winter) temperature and pronounced changes in atmospheric circulation patterns in many regions of the northern hemisphere, especially the North Atlantic realm and Europe. Among the regions affected by the 8.2 kyr B.P. climatic event, the Eastern Mediterranean region is of particular interest for both past and future climate developments. Traditionally characterized as a region highly sensitive to variations in the climate systems of the high and low latitudes, abrupt climate changes have the potential to strongly alter atmospheric circulation patterns and thus precipitation distribution in the region that may have severe socioeconomical consequences. The analysis of stable hydrogen (δD) and oxygen isotopes (δ18O) in precipitation is an excellent tool to trace changes in atmospheric circulation. Here, we present a comparative study of δD and δ18O in precipitation from the Eastern Mediterranean region both in a present day scenario and during the 8.2 kyr B.P. climatic event. We analyze the influences of topography, air mass trajectory, climate and seasonality among others the stable isotopic compositions of meteoric waters from the Central Anatolian Plateau (CAP), Turkey, in order to create a first-order template which may serve as a reference against which paleoenvironmental proxy data may be more accurately interpreted and tested. Further, we employ a multiproxy approach on the early Holocene peat deposits of the classical site of Tenaghi Philippon (TP), NE Greece, to investigate paleoenvironmental responses to northern hemisphere cooling during the 8.2 kyr B.P. climatic event and aim to determine changes atmospheric circulation from δD of leaf wax n-alkanes (δDwax).
Based on δD and δ18O data from more than 480 surface water samples from the CAP, we characterize moisture sources affecting the net isotopic budget of precipitation, manifesting in a systematic north-south difference in near-sea level moisture compositions. Rainout, induced by the major orographic barriers of the plateau, the Pontic Mountains to the north and the Taurus Mountains to the south, strongly shape the modern patterns of δD and δ18O. Stable isotope data from the semi-arid plateau interior provide clear evidence for an evaporitic regime that drastically affects surface water compositions. Strong evaporative enrichment contrasts rainfall patterns along the plateau margins, in part obfuscating the effects of topography and air mass trajectory.
Consequently, in order to address possible influences of evaporation on δD and δ18O in paleoprecipitation from TP, we analyze n-alkane abundances and distributions along with stable carbon isotope compositions of total organic carbon (δ13CTOC) and palynological data to estimate surface moisture conditions during the early Holocene (ca. 8.7 - 7.5 kyr B.P.) and especially during the 8.2 kyr B.P. climatic event. A period of relatively dry surface conditions from ca. 8.7 to 8.2 kyr B.P., indicated by low values of the 'aquatic index' (Paq ) and by elevated Average Chain Length (ACL) values, in concert with elevated δ13CTOC values, precedes the 8.2 kyr B.P. climatic event. The event itself is characterized by slightly wetter, more humid conditions, as suggested by an increase in Paq values as well as reduced ACL and δ13CTOC values between ca. 8.2 and 7.9 kyr B.P.. In the upper section of the core, a distinct change in paleohydrology becomes. A steep increase in Paq and a decrease in ACL values as well as variations in δ13CTOC from 7.9 kyr B.P. onwards imply considerably elevated surface moisture levels, likely caused by the increased activity of the karstic system of the surrounding mountains. Collectively, the biomarker proxies presented here, reveal a concise picture of changing moisture conditions at TP that is consistent with palynological data and provide detailed paleoenvironmental information for the analysis of δDwax as a paleoprecipitation proxy. The long-term decline in δDwax values characterizes the lower section of the core until ca. 8.2 kyr B.P.. The 8.2 kyr B.P. climatic event itself is connected to two distinct positive hydrogen isotope excursions: a minor shift in δDwax around 8.2 kyr B.P. and a major shift in δDwax between ca. 8.1 and 8.0 kyr B.P.. The upper part of the section shows a progressive trend towards higher δDwax values. With no indication of increased evaporitic conditions at TP during the 8.2 kyr B.P. climatic event, as evident in biomarker proxies and pollen data, we link shifts in δDwax to changes in Mediterranean air mass trajectories supplying precipitation to northeastern Greece, with variations in the relative contributions of northerly derived, D-depleted moisture and southerly-derived, D-enriched moisture. Possible control mechanisms include changes in the influence of the Siberian High and differences in the influence of the African and Asian monsoon circulations on anticyclonic conditions in the Mediterranean region as well as regional inflow of moist air from the Aegean Sea.
Forty two samples of the Late Eocene Kiliran oil shale, Central Sumatra Basin, Indonesia were collected from a 102 m long drill core. The oil shale core represents the deposition time of about 240.000 years. Palynofacies and geochemical analyses have been carried out to reconstruct the paleoenvironmental conditions and paleoecology during deposition of the oil shale. Amorphous organic matter (AOM) is very abundant (>76%). B. braunii palynomorphs are present (3-16%) as the only autochtonous structured organic matter and generally more abundant in the middle part of the profile. The stable carbon isotopic composition of bulk organic matter (13C) varies from -27.0 to -30.5‰ and is generally more depleted in the middle part of the profile. The ratio of total organic carbon to sulfur (TOC/S), used as salinity indicator, ranges from 2.5 to 15.8 and shows variations along the profile. Slightly less saline environments are observed in the middle part of the profile. Fungal remains are generally present only in this part with a distinct peak of abundance. The presence of fungal remains is regarded as an indication for a relatively warmer climate during deposition of the middle part of the profile. The warmer climate is thought to influence the establishment of a thermocline, limiting the supply of recycled nutrients to epilimnion. Consequently, the primary productivity in the Kiliran lake decreased during deposition of the middle part of the profile as indicated by the relatively depleted 13C values and the blooming of B. braunii. The chemocline was also shoaling during the deposition according to the higher abundance of total isorenieratane and its derivatives originated from green sulfur bacteria dwelling in the photic zone euxinia. The warmer climate is also thought to influence the slightly decrease of water salinity during deposition of the middle part of the profile. The occurrence of B. braunii in Kiliran lake is also recognized from organic geochemical data. The distribution of n-alkanes is characterized by the unusual high amount of C27 n-alkane relative to the other long-chain n-alkanes. The concentrations of C27 n-alkane vary from 30.1 to 393.7 μg/g TOC and are generally in parallel with the abundances of B. braunii palynomorphs along the profile. The 13C values of this compound are about -31‰ and up to 2‰ enriched relative to those of the adjacent long-chain n-alkanes. B. braunii race A can thus be regarded as the significant biological source of the C27 n-alkane. Lower amounts of lycopane are observed in many oil shale samples (0 to 54.7 μg/g TOC). The 13C value of this compound is 17.2‰. This strong enrichment of 13C suggests that the lycopane was derived from B. braunii race L. The concentrations of lycopane develop generally in opposite with those of C27 μalkane. It is likely that both B. braunii races bloomed in alternation in the lake, probably due to changes on specific water chemistry. Norneohop-13(18)-ene and neohop-13(18)-ene derived from methanotrophic bacteria are the dominant hopanoid hydrocarbons. The sum of their concentrations varies from 40.6 to 360.0 μg/g TOC. The 13C of these compounds are extremely depleted (-45.2 to -50.2‰). The occurrence of abundant bacteria including methanotrophic bacteria was responsible for the recycling of carbon below the chemocline of the lake. The effect of the recycling of carbon is observed by the presence of a concomitant depletion (about 7-9‰) in 13C of some specific biomarkers derived from organisms dwelling in the whole phototrophic zone. 4-Methylsterane and 4-methyldiasterene homologues occur in the oil shale as the predominant biomarkers. The sum of the concentrations of all homologues are about 40.3-1,009.2 μg/g TOC with generally higher values in the uppermost and lower parts of the profile. Calcium (Ca) accounts as the predominant element in the oil shale, ranging from 5.0 to 16.7%. This element shows generally parallel variation with the 4-methylsterane and 4-methyldiasterene homologues along the profile. This suggests that these compounds were derived from biological sources favoring more alkaline and more trophic environments. On the other hand, these compounds were less abundant in the middle part of the profile which is consistent with less alkaline and less trophic environments promoting B. braunii to bloom. Alternation between Dinoflagellates and B. braunii in ancient lacustrine environments due to water chemistry changes have been known from previous studies. In the present case, distinct alternation between B. braunii abundances and concentrations of 4-methylsterane and 4-methyldiasterene homologues along the studied oil shale profile suggest a hypothesis that these compounds were derived from freshwater Dinoflagellates although dinosterane is not present in the sediment extracts. Water alkalinity and trophic level changes were most likely responsible for the alternation of Dinoflagellates and B. braunii blooming.
Terrestrial climate and ecosystem evolution during ‘Greenhouse Earth’ phases of the early Paleogene remain incompletely known. Particularly, paleobotanical records from high southern latitudes are giving only limited insights into the Paleocene and early Eocene vegetation of the region. Hence, data from continuous well-calibrated sequences are required to make progress with the reconstruction of terrestrial climate and ecosystem dynamics from the southern latitudes during the early Paleogene.
In order to elucidate the terrestrial conditions from the high southern latitudes during the early Paleogene, terrestrial palynology was applied in the present study to two well-dated deep-marine sediment cores located at the Australo-Antarctic region: (i) IODP Site U1356 (Wilkes Land margin, East Antarctica) and (ii) ODP Site 1172 (East Tasman Plateau, southwest Pacific Ocean). The studied sequence from IODP Site U1356 comprises mid-shelfal sediments from the early to middle Eocene (53.9 – 46 million years ago [Ma]). For the ODP Site 1172, the studied succession is characterized by sediments deposited in shallow marine environments of the middle Paleocene to the early Eocene (60.7 – 54.2 Ma).
Based on the obtained pollen and spores (sporomorphs) results from the studied sequences of Site U1356 and Site 1172, this study aims to: (1) decipher the terrestrial climate conditions along the Australo-Antarctic region from the middle Paleocene to the middle Eocene; (2) evaluate the structure, diversity and compositional patterns of forests that throve in the Australo-Antarctic region during the early Paleogene; (3) understand the response of forests from the high southern latitudes to the climate dynamics from the early Paleogene; (4) establish a connection between the generated terrestrial palynomorph data and published Sea Surface Temperatures (SSTs) from the same cores.
To decipher the terrestrial climatic conditions on the Australo-Antarctic region, this study relies on the nearest living relative (NLR) concept that assumes that fossil taxa have similar climate requirements as their modern counterparts. This approach was applied to the sporomorph results of Site U1356 and Site 1172, following mainly the bioclimatic analysis. With regard to the structure and diversity patterns of the vegetation from the same region, the present study presents combined qualitative (i.e., reconstruction of the vegetation based mainly on the habitats of the known living relatives) and quantitative (i.e., application of ordination techniques, rarefaction and diversity indices) analyses of the fossil sporomorphs results.
The overall results from the paleoclimatic and vegetation reconstruction approaches applied in the present study, indicate that temperate and paratropical forests during the early Paleogene throve under different climatic conditions on the Wilkes Land margin and on Tasmania, at paleolatitudes of ∼70°S and ∼65°S, respectively.
Specifically, the sporomorph results from Site U1356, suggest that a highly diverse forest similar to present-day forests from New Caledonia was thriving on Antarctica during the early Eocene (53.9 – 51.9 Ma). These forests were characterized by the presence of termophilous taxa that are restricted today to tropical and subtropical settings, notably Bombacoideae, Strasburgeria, Beauprea, Spathiphyllum, Anacolosa and Lygodium. In combination with MBT/CBT paleotemperature results, they provide strong evidence for near-tropical warmth at least in the coastal lowlands along the Wilkes Land margin. The coeval presence of frost tolerant taxa such as Nothofagus, Araucariaceae and Podocarpaceae during the early Eocene on the same record suggests that paratropical forests were thriving along the Wilkes Land margin. Due to the presence of this kind of vegetation, it is possible to suggest that forests in this region were subject to a climatic gradient related to differences in elevation and/or the proximity to the coastline.
By the middle Eocene, the paratropical forests that characterized the vegetation of the early Eocene on the Wilkes Land margin were replaced by low diversity temperate forests dominated by Nothofagus, and similar to present-day cool-temperate forests from New Zealand. The dominance of these forests and the absence of thermophilous elements together with the lower temperatures suggested by the MBT/CBT and the sporomorph-based temperatures indicate consistently cooler conditions during this time interval.
With regard to the sporomorph results of Site 1172, this study suggests that three vegetation types were thriving on Tasmania from the middle Paleocene to the early Eocene under different climatic conditions. During the middle to late Paleocene, warm-temperate forests dominated by Podocarpaceae and Araucariaceae were the prevailing vegetation on Tasmania. The dominance of these forests was interrupted by the transient predominance of cool-temperate forests dominated by Nothofagus and Araucariaceae across the middle/late Paleocene transition interval (~59.5 to ~59.0 Ma). This cool-temperate forest was characterized by a lack of frost-sensitive elements (i.e., palms and cycads) indicating cooler conditions with harsher winters on Tasmania during this time interval. By the early Eocene, and linked with the Paleocene Eocene Thermal Maximum (PETM), Paleocene temperate forests dominated by gymnosperms were replaced by paratropical rainforests with the remarkable presence of the tropical mangrove palm Nypa during the PETM and the earliest Eocene. The overall results from Site U1356 and Site 1172, provide a new assessment of the terrestrial climatic conditions in the Australo-Antarctic region for validating climate models and understanding the response of high-latitude terrestrial ecosystems to the climate dynamics of the early Paleogene on southern latitudes.
The climatic conditions in the higher latitudes during the early Paleogene were further unravelled by comparing the obtained terrestrial and marine results. The integration of the obtained sporomorph data with previously published TEX86-based SSTs from Site 1172 documents that the vegetation dynamics were closely linked with the temperature evolution from the Australo-Antarctic region. Moreover, the comparison of TEX86-based SSTs and sporomorph-based climatic estimations from Site 1172 suggests a warm-season bias of both calibrations of TEX86 (i.e., TEX86Hand TEX86H), when this proxy is applied to high southern latitudes records of the early Paleogene.
Für die Analyse klimagesteuerter terrestrischer und mariner Ökosystemdynamik im Spätglazial und Holozän des Ägäisraums wurden terrestrische (Pollen und Sporen) und marine Palynomorphe (organischwandige Dinoflagellatenzysten) aus einem marinen Kern des Berg-Athos-Beckens hochauflösend (d.h. in einer zeitlichen Auflösung zwischen ~30 und ~200 Jahren) untersucht. Darüber hinaus wurden Pollen und Sporen eines terrestrischen Kerns aus dem Drama-Becken (nördliches Hinterland der Ägäis) analysiert. Neben der qualitativen Analyse wurden mit Hilfe der Technik der modernen Analoge quantitative Rekonstruktionen der Paläotemperaturen und -niederschläge im terrestrischen Raum vorgenommen. Für den marinen Kern wurden außerdem Sedimenthelligkeit, Sauerstoffisotopie und magnetische Suszeptibilität untersucht. Über die Entwicklung eines konsistenten Altersmodells für beide Kerne konnten Aussagen über eine regionale, klimagesteuerte Differenzierung zwischen der Vegetationsentwicklung im Küstenbereich und der Vegetationsentwicklung in intramontanen Ökosystemen getroffen werden. Während des Pleniglazials (~21 ka bis ~14,7 ka BP) herrschten im nördlichen Ägäisraum kühle und vor allem trockene Bedingungen vor. Offen liegende Schelfflächen wurden von einer Pinus-dominierten Vegetation besiedelt, bis der Schelf während des anschließenden Meiendorf-Bølling-Allerød-Interstadialkomplexes (~14,7 ka bis ~12,7 ka BP) durch den Schmelzwasserpuls MWP-1A überflutet wurde. Während des Meiendorf-Bølling-Allerød-Interstadialkomplexes herrschten im nördlichen Ägäisraum etwas humidere Bedingungen als während des Pleniglazials. In der anschließenden Jüngeren Dryas (~12,7 ka bis ~11,7 ka BP) war das Klima hingegen mindestens ebenso arid und die Oberflächenwassertemperaturen in der Nordägäis fast ebenso gering wie während des Pleniglazials. Das lokale Klima im Drama Becken war von ~21 ka BP bis zum Ende der Jüngeren Dryas generell trockener als die allgemeinen Klimabedingungen im nördlichen Ägäisraum. Die Vegetationsentwicklung im nördlichen Ägäisraum wurde während des Spätquartärs vor allem durch die zur Verfügung stehende Feuchtigkeit gesteuert. Auch nach der Jüngeren Dryas war die Humidität im Ägäisraum zu gering, um eine Wiederbewaldung zu ermöglichen, wie sie in Mitteleuropa und dem westlichen Mittelmeergebiet bereits ab ~11,6 ka BP stattfand. Ein Vegetationsrückschlag um ~11,0 ka BP korreliert mit der aus Mitteleuropa bekannten präborealen Oszillation bzw. dem 11,2-ka-Klimaereignis. Die holozäne Wiederbewaldung setzte im östlichen Ägäisraum erst ab 10,2 ka BP ein; sie wurde durch einen sukzessiven Anstieg der Winterniederschläge von ~225 auf über ~300 mm/Jahr ermöglicht. Sowohl dieser Anstieg der Winterniederschläge als auch ihr Rückgang nach 7,0 ka BP sind eng mit der Ablagerung des Sapropels S1 (zwischen ~9,6 ka und ~7,0 ka BP) verknüpft. Die relativ humiden und milden Winterbedingungen während der Ablagerung des S1 wurden von durch Vegetationsrückschläge dokumentierten, kurzfristigen Klimaereignissen bei ~9,3 ka, ~8,7 ka, ~8,2 ka und ~7,6 ka BP unterbrochen. Diese kurzfristigen Klimaereignisse gehen mit Unterbrechungen bzw. Abschwächungen der S1-Bildung einher. Besonders ausgeprägt ist der regionale Ausdruck des 8,2-ka-Ereignisses, welches für die am stärksten ausgeprägte und auch aus anderen Bereichen des östlichen Mittelmeers überlieferte Unterbrechung des S1 zwischen ~8,4 ka und ~8,0 ka verantwortlich zeichnet. Während der Bildung des S1 wurde die Klimaentwicklung im Ägäisraum generell weniger vom Klimasystem der hohen Breiten beeinflusst als vielmehr vom Monsunsystem der niederen Breiten. Allerdings war die Intensität des Sibirischen Hochs während des frühen Holozäns und nach dem S1-Intervall ein wichtiger Faktor für das Winterklima. Auch während des Holozäns wurden Klimaschwankungen im Drama-Becken deutlicher von der lokalen Vegetation reflektiert als von der Vegetation des nördlichen Ägäisraums im Allgemeinen. So wirkte sich z.B. das 8,2-ka-Ereignis sehr stark auf die Vegetationsentwicklung im Drama Becken aus; es verursachte einen Rückgang der Sommer- und Wintertemperaturen um mehr als 3° C. Dieser starke Temperatureinbruch ist auf lokale mesoklimatische Effekte zurückzuführen. Die Vegetation in den Randbereichen der Ägäis erfuhr weitere Rückschläge bei ~6,5 ka, ~5,6 ka und ~4,3 ka BP. Die Einbrüche bei ~5,6 ka und ~4,3 ka BP sind mit rapiden Klimaänderungen in großen Teilen der Nordhemisphäre korrelierbar, die ebenso wie die Jüngere Dryas und das 8,2-ka-Klimaereignis Einfluss auf Hochkulturen in Nordostafrika und im Mittleren Osten hatten. Die aus dem Holozän überlieferten Klimadaten machen deutlich, dass dieser Zeitraum von einer weitaus stärkeren Klimavariabilität geprägt wurde als noch bis vor kurzem angenommen.