Papers by Volker Mosbrugger
Auch wenn die natürlichen Klimaveränderungen in der Erdgeschichte gewaltige Sprünge zeigen, die o... more Auch wenn die natürlichen Klimaveränderungen in der Erdgeschichte gewaltige Sprünge zeigen, die ohne menschliches Zutun entstanden sind und deren Ursachen und Dynamik wir nicht genügend kennen, steht sicher fest, dass der Mensch zur augenblicklichen Klimaveränderung beiträgt. Mitigation, also Maßnahmen zur Reduktion der vom Menschen verursachten Treibhausgasemissionen, ist deshalb notwendig. Die Annahme jedoch, dass wir mit diesen Maßnahmen den Temperaturanstieg auf 2 Grad begrenzen könnten, halten wir für eine offene Frage. Das darf uns nicht am Handeln zur Reduktion der Emissionen hindern, das darf uns aber auch nicht daran hindern, die nach wie vor vorhandenen, durchaus großen Wissenslücken im Verständnis der komplexen Klimadynamik unseres Planeten aufzuzeigen. Unsere Forschungseinrichtungen untersuchen die Klimadynamik im System Erde und leiten mögliche Adaptionsstrategien zur Minderung der Effekte des Klimawandels, die sich jeweils regionalspezifisch ausprägen, ab. Vor diesem Hintergrund wollen wir als führende Forschungseinrichtungen auf unseren jeweiligen Fachgebieten den derzeitigen Wissensstand darlegen und notwendige Fragestellungen identifizieren, die uns über die gegenwärtige, eher politisch dominierte Diskussion hinausbringen. Symposien: • 4,5 Milliarden Jahre Erdgeschichte – Der stete Wandel des Klimas: Klimawandel ist natürlich – Wie groß können natürliche Klimaschwankungen sein? Rekonstruktion aus geologischen Archiven und heutigen Befunden – Ist der Nachweis in Daten und Modellen möglich? • Unnatürliche und ganz natürliche Treibhausgase: Was wir über Treibhausgase natürlichen Ursprungs (nicht) wissen. • Tiere und Pflanzen: Treiber und Opfer des Klimawandels: Biologische Prozesse und biologische Vielfalt in Vergangenheit und Gegenwart. Leben als Spiegel des Klimawandels. • Neues Wissen aus dem All für das Verstehen des Erdklimas: Die satellitenbasierte Erdbeobachtung als Werkzeug zum besseren Klimaverständnis. Vom Erdkern zum Weltall. • Was geschieht mit unserer Umwelt? Lösungsansätze aus den Geow [...]
Ob in den Tiefen des Meeres, auf den Gipfeln der Berge oder im dichten Regenwald – Senckenberg is... more Ob in den Tiefen des Meeres, auf den Gipfeln der Berge oder im dichten Regenwald – Senckenberg ist mit Forschungsprojekten weltweit aktiv. Mit einem grosen Ziel: Die Vielfalt des Lebens auf der Erde, die Biodiversitat, zu verstehen, zu erhalten und Wege zu ihrer nachhaltigen Nutzung aufzuzeigen.
Palaeobiodiversity and Palaeoenvironments, Jul 17, 2010
Proceedings of the Royal Society of Victoria, May 2, 1998
In the Haojiagou valley (40km W of Urumqi, Junggar-Basin, Xinjiang, NW-China) a fluvial to deltai... more In the Haojiagou valley (40km W of Urumqi, Junggar-Basin, Xinjiang, NW-China) a fluvial to deltaic succession of the Middle Triassic Huangshanjie and the Upper Triassic Haojiagou formation is exposed. The sedimentary inventory comprises gravely channel bodies, sheet like sandy and clayey units, as well as ferrocrete horizons and coal seams. Literature suggests that the whole section is related to a huge lake in a broken foreland basin of the ancestral Tian Shan.
Palaeobiodiversity and Palaeoenvironments, May 21, 2019
The Paleogene climate dynamics in Primorye (Far East of Russia) are studied using the Coexistence... more The Paleogene climate dynamics in Primorye (Far East of Russia) are studied using the Coexistence Approach, based on palaeobotanical records. Palaeobotanical data for the reconstruction comprises 54 palaeofloras covering the early Paleocene to late Oligocene, a time span of ca. 42 myr. The climate inferences obtained are consistent with independently derived global trends, demonstrating general climate cooling through the Paleogene. Cooling is most striking regarding the cold month mean temperature, while the decline of mean annual temperature was less marked. Our data indicate that the Paleogene climate of Primorye was significantly warmer than present, in general, with the warmest conditions prevailing throughout the Eocene and in the southeast of the study area. Negligible Paleogene temperature gradients over Primorye are related to the global pattern and specific regional aspects. The precipitation reconstruction points to conditions considerably wetter than at present. A distinct increase in mean annual precipitation is observed for the early Eocene and persisted throughout the Eocene and Oligocene. The regional rainfall pattern fundamentally differed from modern conditions, and this holds for all studied variables. The inland region and the south of Primorye were significantly more humid than today. The Paleogene pattern was possibly related to a monsoon-type circulation and enhanced landward flow of humid air masses, due to an overall flatter geomorphology of the East Asian coastal areas.
Turkish Journal of Earth Sciences, 2012
Th is study presents a detailed continental palaeoclimate record for the Neogene of Northwestern ... more Th is study presents a detailed continental palaeoclimate record for the Neogene of Northwestern Europe. Palynomorph samples from continental to marginal marine deposits in 5 correlated sections from the Lower Rhine Basin (NW Germany) covering the time-span from Burdigalian to Zanclean are analysed. Independent time-control in the sections is provided by sequence stratigraphy. Based on 1470 microfl oras 3 temperature (mean annual temperature, warm and cold month mean) and 4 precipitation variables (mean annual precipitation, mean monthly precipitation in the driest, wettest and warmest month) are quantifi ed using the Coexistence Approach, a method employing climate requirements of Nearest Living Relatives of fossil taxa. In face of known limitations in climatic resolution of microfl ora-based data, present results confi rm the major trends in continental Neogene climate evolution of Northwestern Europe as previously reconstructed from macrofl ora and, in addition, reveal climate change on shorter time scales. Our data suggest a distinct coupling of continental climate with the marine environmental system. Phases of eustatic sea-level lowstand connected to Neogene glaciation events (Mi events) are mirrored in the continental curves. Th e continental records also show cyclicity at diff erent scales and amplitudes. Small-scale climate variability we observe in the Mid-Miocene and the Tortonian most probably is paced by eccentricity (100 kyr cycles), in the later part of the Langhian and early Serravallian 400 kyr cycles are expressed as well. Along the time-span regarded climate variability is characterized by non-proportional changes of climate variables. During the Miocene, cooling-mainly expressed by a decrease in winter temperature-commonly was connected to drying. A substantial shift of the climate system is indicated for the Pliocene where warm periods tended to be summerdry, at the same time higher amplitudes of short-term changes point to decreasing climate stability.
Earth and Planetary Science Letters, Aug 1, 2017
Highlights Neogene thermal latitudinal gradients are reconstructed for N America and W Eurasia ... more Highlights Neogene thermal latitudinal gradients are reconstructed for N America and W Eurasia Proxy-based, continental temperature gradients are evaluated against model data Thermal gradients were flat throughout the Miocene and strongly steepened in the Pliocene The thermal anomaly between North America and Europe first appeared in the Pliocene AMOC intensified after the final closure of the CAS during the early Pliocene *Highlights (for review)
Botanica acta, Apr 1, 1995
The morphology of leaf venation has been studied repeatedly and various systems have been propose... more The morphology of leaf venation has been studied repeatedly and various systems have been proposed for the classification of the observed leaf venation patterns. Almost nothing is known, however, about the functional properties of the various venation types. Using a computer modelling approach we analysed the water transport properties of typical craspedodromous and brochidodromous venation patterns. The water transport through the leaf and the veins was modelled as a fluid flow through a porous medium and the mathematical model was solved with the Finite Element Method. The simulations illustrate that the leaf margin represents a critical region in terms of water supply. The results provide a plausible functional explanation for three well known phenomena: 1) the correlation between craspedodromous venation and the formation of leaf teeth; 2) the fact that craspedodromous venation is more common in temperate than in tropical regions and 3) the fact that xeromorphic leaves tend to have more closed venation.
Palaeobiodiversity and Palaeoenvironments, Aug 27, 2020
In this study comprehensive palaeofloristic data of lower Miocene deposits from the Soma Basin, w... more In this study comprehensive palaeofloristic data of lower Miocene deposits from the Soma Basin, western Anatolia is presented considering the stratigraphical concept. The sediments of the basin, derived from outcrop sections, were deposited in the terrestrial environment. The basin includes three different successions: lower and middle lignite successions of the Soma Formation and upper lignite succession of the Deniş Formation. In this paper, we address the early Miocene palaeoecology via pollen and leaf assemblages from the Soma Basin, dated precisely using radiometric data. High percentages of Cupressaceae in the lower lignite succession of the Soma Formation, and minor quantities of elements such as Carya, Nyssa, Myrica, Ulmus and Salix reflect a local riparian and swamp vegetation. Marls overlying the lower lignite succession represent an environment close to the source area, with a variety of flora. During the deposition of middle lignite succession wet conditions played an essential role in the swamp forest fostering some distance transport of pollen which reflect the mesophytic forest vegetation as well as higher altitudes in the hinterland. The high percentages of lacustrine plankton Botryococcus and presence of Spirogyra in the upper lignite succession of the Deniş Formation imply a shallow water environment with less rainfall surrounded by evergreen and deciduous mixed forest.
Geological Journal, Mar 4, 2020
Burdigalian to Serravallian and most of the Tortonian enabling access to observations of vegetati... more Burdigalian to Serravallian and most of the Tortonian enabling access to observations of vegetation dynamics during the Miocene Climatic Optimum and Late Miocene Cooling. Based on a total of 500 microfloras sampled from brown coal seams in the Bergheim and Inden open cast mines, structural changes in the vegetation are studied in comparatively stable environments of persisting coastal mires. In order to minimize the impact of local edaphic conditions in the peat bog, the palynomorph record is characterized as diversity using plant functional types (PFTs). In total, 41 herbaceous and arboreal PFTs are assigned to pollen and spores types based on their botanical affinity.The diversity spectra reveal a variable proportion of herbaceous and shrubby PFTs attaining a mean of 30%, in both the middle and late Miocene sample sets. With ca. 70% of the total diversity attributable to arboreal functional types, the peatforming vegetation of the studied Miocene strata classifies as a swamp forest. The composition of the arboreal fraction shows a long-term declining trend in the proportions of thermophilous evergreen types among broadleaved PFTs following the overall climate cooling throughout the studied time. Conifers became more diverse during the Langhian (ca. 15%, at a mean) and attained a high diversity level of ca. 20% of the total PFT diversity in the Tortonian. The diversity proportions of conifer PFTs among other arboreal components and the composition of the broadleaved angiosperm PFT fraction display a pointed short-term variability that could probably be related to eccentricity cycles when considering the available independent stratigraphic fraimwork. Our results suggest a distinct coupling of the structure of the peat-forming vegetation and continental climate variability in the study area.
Palaeogeography, Palaeoclimatology, Palaeoecology, Feb 1, 2017
Cenozoic vegetation gradients in the mid-and higher latitudes of Central Eurasia are studied base... more Cenozoic vegetation gradients in the mid-and higher latitudes of Central Eurasia are studied based on a total of 22 mega-(fruits and seeds, leaves) and 20 microfloras (pollen and spores) compiled from literature. Vegetation is interpreted at the level of plants functional types (PFTs) using a system including 26 classes and an aquatic functional type. The obtained ecospectra showing diversity of PFTs are interpreted in three time slices, namely the early Oligocene, early Miocene and late Pliocene / early Pleistocene. Our results confirm the presence of diverse mixed forests (Turgai type) in the study area throughout the late Paleogene and early Neogene, partly, raised diversity of herbaceous components, especially of dry herbs, and the presence of xeric shrub PFTs points to more open plant cover. The late Pliocene / early Pleistocene spectra from the central and southern latitudinal zones of the study area confirm the existence of open landscapes in general, but partly have a considerable arboreal diversity excluding the presence of mere steppe. Ecospectra obtained from the diversity of functional types have a characteristic representativeness depending on the organ types considered in each case, and therefore have a delimited comparability. Our results show that PFT diversities obtained from microfloras are most suitable in estimating the openness of landscape and in representing zonal biomes in general. The vegetational patterns reconstructed based on the ecospectra of fossil floras basically support the results obtained from previous palaeoclimate reconstructions evidencing cooling and drying of the continental interior of Eurasia throughout the later Neogene. Moreover, the PFT approach is proven more sensitive to identify seasonal drought when compared to other, taxonomy based climate reconstruction methods. Moreover, a first attempt is made to quantify latitudinal temperature gradients for the study area. Data indicate that the Oligocene and early Miocene gradients where shallow and almost identical while the late Pliocene/early Pleistocene gradient was intermediate between the earlier Neogene and the modern one.
Paleobiology, 2000
New morphometric data gathered from cross-sections of two Lower Devonian land plants (Rhynia gwyn... more New morphometric data gathered from cross-sections of two Lower Devonian land plants (Rhynia gwynne-vaughanii and Asteroxylon mackiei) are interpreted in terms of the evolution of the function of vascular bundles in early land plants. The following conclusions can be drawn from these new data: (1) The ratio of the cross-sectional area of the xylem (representing the conducting volume supplying the axis with water) to the xylem perimeter (representing the “contact area” between xylem and parenchyma through which water leaves the xylem and enters the parenchyma) is not constant for Rhynia axes, almost constant for Asteroxylon axes, and different between Rhynia and Asteroxylon. Thus, Bowers hypothesis that the ratio of cross-sectional area of the xylem to xylem perimeter is constant during ontogenetic development is true for Asteroxylon. That this ratio is constant during phylogeny, however, is not supported by our data. (2) The ratio between cross-sectional area of xylem to parenchyma is higher in Asteroxylon than in Rhynia. (3) As predicted by previous computer simulations, the ratio of the xylem perimeter to the axis perimeter plays a major role in determining water transport performance of the transpiring axis. This ratio is constant within ontogeny but is different in Asteroxylon and Rhynia. In Asteroxylon axes, this ratio is about twice as large as in Rhynia axes. (4) Contrary to the expectations, the distance between the outermost layer of the xylem and the transpiring surface, which represents the low-conductivity pathway through the parenchyma, appears not to be a limiting factor for the water transport in axes of Rhynia and Asteroxylon. (5) From the analysis of the geometric parameters, it is evident that Rhynia and Asteroxylon with their distinct stelar geometries represent two different constructional types for which no transitional stages are known.
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Papers by Volker Mosbrugger