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This paper provides quantitative reconstructions of the Lateglacial changes in four climate parameters from two fine-resolution pollen profiles in the Gutaiului Mountains, NW Romania. Climate estimates are based on two modern analogue techniques (with and without considering vegetation types) and weighted averaging partial least squares regression (WA-PLS), giving evidence for several climatic fluctuations during the period from > 14,700 to 11,500 cal. yr BP. The comparative results of the two modern analogue techniques show consistent trends of climate changes that are also coherent at both sites, but these results appear to largely disagree compared with climate reconstruction provided by WA-PLS. The modern analogue techniques revealed four intervals with low temperatures: prior to 14,700 cal. yr BP, between 13,950 and 13,800; 13,400 and 13,200; and 12,700 and 11,700 cal. yr BP. The temperature declines were more pronounced for winter than for summer, suggesting an intensification of seasonality, which together with a drop in precipitation indicates an increase in continentality. The Younger Dryas is the most pronounced cooling phase with winter temperatures ~ 14–16 °C colder than modern conditions, annual and summer temperatures ~ 2–5 °C and ~ 2 °C, respectively below present ones. Precipitation was ~ 400–500 mm, half that of present. During the Bolling and Allerod, summer temperatures were close to modern values (13 to 17 °C), whereas winter (− 6 to − 12 °C) and annual temperatures (0.5 to 6 °C) as well as precipitation were (550 to 700 mm) lower, indicating more continental conditions compared to the present-day climate.

A modern analogue technique is applied to two high-resolution pollen sequences from NW Romania to provide the first quantitative evidence for winter, summer and annual temperatures and for precipitation across the Holocene in this region. The pollen-based climate reconstructions allow the identification of four main intervals: i) an early, less stable period between 11,700 and 11,200 cal. yr BP; (ii) generally stable conditions between 11,200 and 8300 cal. yr BP with winter and annual temperatures and precipitation higher than at present, and summer temperatures about the same; (iii) lower winter and annual temperatures, and higher summer temperatures and precipitation between 8000 and 2400 cal. yr BP; (iv) warmer winter and annual temperatures and lower precipitation for the last 2400 years, whereas summer temperatures became cooler at Steregoiu and remained stable at Preluca Tiganului. The pollen-based climate reconstructions at the two sites show similar patterns in annual and winter temperatures and precipitation changes during the Holocene, but the trends appear to be less consistent for summer temperatures. Our pollen-based reconstructions revealed several short-term climatic oscillations during the Holocene, the strongest of which occur between 10,300–10,100, 8300–8000, 6800–6400, 5100–4900, 4000–3600 and 3200–3000 cal. yr BP.

Previous studies from Central Europe and North America showed that species richness is higher in urban than in rural landscapes. Do protected areas, which can be found in both city and countryside, reflect this species richness pattern? The impact of urban land-use might reduce conservation success and necessitate special management strategies. We compared species richness and species spatial turnover of selected animal and plant taxa (carabids, butterflies, snails, birds, lichens, mosses, vascular plants) in 30 protected areas in the city of Halle and 56 protected areas in the adjacent rural district of Saalkreis (Central Germany). Species were mapped by experienced biologists within a systematic species inventory. We corrected species numbers for the effects of landscape structure (e.g. size, shape and distance of habitats) which might influence species diversity beyond urbanisation effects. Butterflies, birds and lichens had significantly higher species numbers in the rural protected areas. Species spatial turnover was higher among urban areas than among rural areas or pairs of urban and rural areas for most taxa. Diversity in all taxa depended on the size of a protected area. We discussed these patterns in the context of the general urban-rural species diversity patterns. Our results indicate an increasing isolation of species assemblages with urbanisation and highlight that space for protected areas is even more limited in urban than rural areas. An effective conservation of urban species diversity should include both typical urban and semi-natural habitats to cover the full range of species living in cities.

The results of palynological studies of the Oligo-Miocene in the western part of the Euxinian Basin (Eastern Paratethys) are based on the analysis of 57 samples from core C-136A drilled near the town of Balchik, Varna district. Some samples were barren or contained very little pollen and were not included in the analysis. Quantitative data are thus confined to 26 polleniferous samples. We present results for the Upper Oligocene as well as the Tarkhanian, Karaganian, Bessarabian, and Chersonian stages of the middle to upper Miocene. Mixed deciduous forests were widespread during the time period studied. Swamp forests are also recorded, with distribution maxima observed in the Oligocene and in the Bessarabian. The widest extent of herbaceous vegetation is recorded in the late Bessarabian and Chersonian, when it occupied open landscapes after a marine regressional phase. The climatic data reconstructed by the Coexistence Approach indicate mean annual temperatures (MATs) of ca. 15–17 °C and mean annual precipitation (MAPs) of 800–1300 mm for the Upper Oligocene. The narrowest coexistence intervals of the Tarkhanian and Karaganian display MATs of 14–17 °C and MAPs of 800–1300 mm. The most substantial data are for the Bessarabian, in which the lower part is characterized by MATs of 15.6–16.6 °C and MAPs from 800–1200 (1300) mm. The results for the upper part of the Bessarabian are more variable, especially with respect to precipitation that is generally lower (700–800 mm). The same is true for the Chersonian, where besides lower precipitation, lower annual temperature and temperature of coldest month are observed. These results correlate with previous vegetation and palaeoclimate data from the Forecarpathian Basin (NW Bulgaria).

Pollen, micro-charcoal and total carbon analyses on sediments from the Turbuta palaeolake, in the Transylvanian Basin of NW Romania, reveal Younger Dryas to mid-Holocene environmental changes. The chronostratigraphy relies on AMS 14C measurements on organic matter and U/Th TIMS datings of snail shells. Results indicate the presence of Pinus and Betula open woodlands with small populations of Picea, Ulmus, Alnus and Salix before 12,000 cal yr BP. A fairly abrupt replacement of Pinus and Betula by Ulmus-dominated woodlands at ca. 11,900 cal. yr BP likely represents competition effects of vegetation driven by climate warming at the onset of the Holocene. By 11,000 cal yr BP, the woodlands were increasingly diverse and dense with the expansion of Quercus, Fraxinus and Tilia, the establishment of Corylus and the decline of upland herbaceous and shrubs taxa. The marked expansion of Quercus accompanied by Tilia between 10,500 and 8000 cal yr BP could be the result of low effective moisture associated with both low elevation of the site and with regional change towards a drier climate. At 10,000 cal yr BP, Corylus spread across the region, and by 8000 cal yr BP it replaced Quercus as a dominant forest constituent, with only little representation of Picea abies. Carpinus became established around 5500 cal yr BP, but it was only a minor constituent in local woodlands until ca. 5000 cal yr BP. Results from this study also indicate that the woodlands in the lowlands of Turbuta were never closed.

To improve our understanding of long-term climate changes during the Neogene in Eurasia, the international research network NECLIME — Neogene Climate Evolution in Eurasia was established in the year 2000. In this first synthesis, results of NECLIME activities focussing on the Miocene of Europe as one key area are combined to present a summary of the climate evolution in time and space. More than 300 Miocene fossil floras have been compiled and quantitatively analysed in terms of several climatic parameters during the last few years. In this volume alone, about 75 new data sets are available. To synthesize the results of this volume, quantitative climate maps for Europe are generated on palaeogeographic maps for Langhian and early Tortonian for the first time. Characteristic climate patterns appear for each time interval and can be related to both global climate change and Alpine tectonics. Generally, the climate maps combine and support the individual results discussed in this volume for the individual regions.

In the present study, 14 published megafloras from the Serbian Cenozoic are analyzed with respect to vegetation type, palaeoclimate, and palaeogeographic settings. The floras cover a time-span from the Oligocene to the late Miocene. The results obtained are compared with continental climate records from other parts of Europe and discussed in the context of global climate change. To obtain a quantitative palaeoclimate record a total of seven different climate variables is calculated for each of the floras using the Coexistence Approach. It is shown that basic patterns of vegetation change, such as the immigration of arcto-tertiary, deciduous floristic elements during the early Miocene and the decreasing diversity of laurophyllous taxa during the late Miocene, are ruled by climate change and a changing palaeogeography. The Serbian Cenozoic climate record shows a steep cooling gradient during the Oligocene that is most probably is connected to a northward movement of tectonic plates. The globally observed Middle Miocene Climate Optimum and the Late Miocene Cooling are well reflected. According to the palaeotemperatures calculated a warm temperate climate existed in Serbia throughout the time-span examined. The Late Miocene Cooling is most pronounced in winter temperatures and is connected to increasing seasonality. Precipitation rates obtained for the Serbian Cenozoic, especially those of the warmest and wettest months, tend to be lower when compared to the Central European Cenozoic. According to climate analysis and the interpretation of vegetational data there is evidence for regionally drier conditions and increased seasonality of precipitation in the time-span from the late Badenian to the early Sarmatian.

In the present study, published Miocene mega- and microfloral records compiled from a total of 92 localities in Western Eurasia are analysed with respect to diversity of different plant functional types (PFTs). To study spatial diversity patterns and their evolution three time-intervals are selected corresponding to the Langhian (16.3–13.6 Ma), the Serravallian (13.6–11.6), and the earlier part of the Tortonian (11.6–8.5 Ma). First all arboreal species occurring in the floras are classified using a total of 13 different PFTs (functional types of trees and climatically defined subtypes). In a next step, diversity spectra with respect to these PFTs are generated for each site. Cluster analysis is then performed in order to obtain groups of floras with similar spectra that are interpreted in terms of vegetation type. Their spatial distribution in each time-interval is shown in maps. According to these results, zonally arranged patterns are obtained. Broadleaved Deciduous Forests are most important in the higher latitudes while Mixed Mesophytic Forests dominate the mid-latitudes in Western Eurasia. Broadleaved Evergreen Forests are of minor importance in the area of interest. The observed diversity patterns and their changes in time are correlated with spatial climate patterns and the continental palaeoclimate evolution. During the late Miocene cooling, Broadleaved Evergreen Forests completely disappear from the mid-latitudes of Western Eurasia, and Mixed Mesophytic Forests of the mid-latitudes are mostly replaced by broadleaved deciduous vegetation types. In the context of this cooling, a drier season became established in Western Europe during the Tortonian, as is evident from reconstructed arboreal diversity data and precipitation data. In Central Europe, vegetation types indicating permanently humid conditions persisted throughout all the three time-intervals analysed.

For the Tortonian (Late Miocene, 11 to 7 Ma), we present a model simulation using the atmospheric general circulation model (AGCM) ECHAM4 coupled to a mixed-layer (ML) ocean model. The Tortonian simulation with ECHAM4/ML includes an adjusted weaker than present ocean heat transport, a generally lower palaeorography and an appropriate palaeovegetation. We analyse the climatic differences between the Tortonian run and the present-day control experiment, and we validate our Tortonian model results for the mean annual temperature and the annual precipitation with quantitative terrestrial proxy data. Globally, the Tortonian run is slightly warmer (+ 0.6 °C) and the global precipitation indicates more humid conditions (+ 27 mm/a) than the PD control run. Particularly the northern high latitudes are warmer (+ 3.5 °C) in the Tortonian simulation which leads to a weaker meridional temperature gradient than today as well as to a reduction of polar sea ice. We attribute the polar warming to the lowering of the Greenland elevation (+ 20 °C) in the Miocene and to the effects of the palaeovegetation. The reduced altitude of the Tibetan Plateau causes a warming (+ 20 °C) as compared to today and leads to a weaker Asian monsoon in the Tortonian run. For Europe, the mean annual temperature is almost unaffected as compared to today because a cooling effect of the weak palaeocean heat transport is compensated by the palaeovegetation. When validating our model results, we find that the Tortonian run is largely consistent with quantitative proxy data. However, the high latitudes tend to be generally too cool in the palaeoclimate simulation and the equator-to-pole temperature gradient is too steep as compared to proxy data. For Europe the comparison with proxy data indicates that the Tortonian simulation underestimates the mean annual temperatures, but precipitation patterns are quite consistent between model results and proxy data. Overall, the Tortonian run is quite realistic and hence the model simulation contributes to a better understanding of the relevant climate processes in the Miocene. However, the discrepancies to proxy data demonstrate that we still do not sufficiently understand the Late Miocene climate.

Das Tibetische Hochplateau hat uber die letzten funfzig Millionen Jahre entscheidend das globale Klima beeinflusst. Im Seeschlamm des Nam Co suchen deutsche und chinesische Forscher nach den Spuren folgenreicher Klima- und Umweltveranderungen

For the Tortonian, Steppuhn et al. [Steppuhn, A., Micheels, A., Geiger, G., Mosbrugger, V., 2006. Reconstructing the Late Miocene climate and oceanic heat flux using the AGCM ECHAM4 coupled to a mixed-layer ocean model with adjusted flux correction. Palaeogeography, Palaeoclimatology, Palaeoecology, 238, 399–423] perform a model simulation which considers a generally lower palaeorography, a weaker ocean heat transport and an atmospheric CO2 concentration of 353 ppm. The Tortonian simulation of Steppuhn et al. [Steppuhn, A., Micheels, A., Geiger, G., Mosbrugger, V., 2006. Reconstructing the Late Miocene climate and oceanic heat flux using the AGCM ECHAM4 coupled to a mixed-layer ocean model with adjusted flux correction. Palaeogeography, Palaeoclimatology, Palaeoecology, 238, 399–423] demonstrates some realistic trends: the high latitudes are warmer than today and the meridional temperature gradient is reduced. However, the Tortonian run also indicates some insufficiencies such as too cool mid-latitudes which can be due to an underestimated pCO2 in the atmosphere. As a sensitivity study, we perform a further model experiment for which we additionally increase the atmospheric carbon dioxide (700 ppm). According to this CO2 sensitivity experiment, we find a global warming and a globally more intense water cycle as compared to the previous Tortonian run. Particularly the high latitudes are warmer in the Tortonian CO2 sensitivity run which leads to a lower amount of Arctic sea ice and a reduced equator-to-pole temperature difference. Our Tortonian CO2 sensitivity study basically agrees with results from recent climate model experiments which consider an increase of CO2 during the next century (e.g. [Cubasch, U., Meehl, G.A., Boer, G.J., Stouffer, R.J., Dix, M., Noda, A., Senior, C.A., Raper, S., Yap, K.S., 2001. Projections of Future Climate Change. In: Houghton, J.T., Y. Ding, D.J. Griggs, M. Noguer, P.J. van der Linden, X. Dai, K. Maskell, C.A. Johnson (eds.), Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, 525–582]) suggesting that the climatic response on a higher atmospheric CO2 concentration is almost independent from the different settings of boundary conditions (Tortonian versus today). To validate the Tortonian model simulations, we perform a quantitative comparison with terrestrial proxy data. This comparison demonstrates that the Tortonian CO2 sensitivity experiment tends to be more realistic than the previous Tortonian simulation by Steppuhn et al. [Steppuhn, A., Micheels, A., Geiger, G., Mosbrugger, V., 2006. Reconstructing the Late Miocene climate and oceanic heat flux using the AGCM ECHAM4 coupled to a mixed-layer ocean model with adjusted flux correction. Palaeogeography, Palaeoclimatology, Palaeoecology, 238, 399–423]. However, a high carbon dioxide concentration of 700 ppm is questionable for the Late Miocene, and it cannot explain shortcomings of our Tortonian run with ‘normal’ CO2. In order to fully understand the Late Miocene climate, further model experiments should also consider the palaeovegetation.

A 3-Ma pollen record was obtained from a continuous red clay–loess–paleosol sequence at Chaona in the central Chinese Loess Plateau (CLP). The record shows a permanent change of a domination of typical Cupressaceae forest vegetation representative of an ecological environment with a relative warm and humid climate during 3.0–2.6 Ma to largely steppe vegetation under dry climate conditions after 2.6 Ma. The later is further manifested itself as steppe to forest or forest–steppe (spruce forest — mostly mesophilous herbs) between 2.6 Ma and 1.5 Ma, forest–steppe (pine–grass) between 1.5 Ma and 0.95 Ma, open forest–steppe (mesophilous and xeromorphic herbs–pine) between 0.95 Ma and 0.5 Ma, and steppe (xeromorphic herbs) after 0.5 Ma, suggesting a process of stepwise aridification in Central Asia at the late Pliocene and the Quaternary.

Eocene vegetation patterns and continental temperatures are reconstructed from the palaeobotanical record on a global scale. A total of 100 macrofloras and 45 microfloras compiled from published sources is analysed studying diversities of plant functional types and phytosociological types. The spatial patterns obtained from the diversity of plant functional types reflect the distribution of major Eocene ecosystems. As shown by the analysis different forest associations were most important with trees reaching over 50% of the total diversity in 92% of the localities. Using a phytosociological classification scheme employing the ecological requirements of the Nearest Living Relatives of fossil taxa the single floras are analysed by multivariate statistical methods. As a result the Eocene sites are allocated to 7 different groups which can be interpreted in terms of Eocene vegetation units. The distribution of these units is shown in palaeogeographical maps. It is shown that in the Eocene, major vegetation units were zonally arranged. Most of the floras located north and south of 15° latitude are classified as extra-tropical. There is evidence for seasonally drier climate conditions in some regions, but no indication for xerophytic vegetation types. The vegetation of the mid-latitudes is characterized by a very high diversity of evergreen angiosperm woods, especially in the Tethyan realm. The high Northern latitudes were covered by temperate deciduous and mixed deciduous vegetation. The reconstructed vegetational patterns are well in accordance with results obtained from the analysis of various proxy data indicating the existence of very warm high latitudes and a shallow latitudinal temperature gradient during the Eocene.

The reconstruction of the climate in the Miocene Shanwang basin is an important link in understanding past climate and environmental changes in East Asia. A recent study showed that the mean annual temperature (MAT) estimates derived from leaf margin analysis (LMA) and the Climate Leaf Analysis Multivariate Program (CLAMP) conflicted with and were remarkably lower than those estimated by the coexistence approach (CA). Overlapping distribution analysis (ODA), a new method introduced here, is used to reconstruct the Shanwang Miocene climate based explicitly on local plant distribution data and associated meteorological stations. The Shanwang flora (17–15.2 Ma) suggests a MAT of 10.9–14.5°C and a mean annual precipitation (MAP) of 1107.3–1880.0 mm. This result is closer to the values derived from CLAMP and LMA than that obtained by CA. This report is the first comprehensive intercomparison of foliar physiognomic and nearest living relative climate proxies in a Chinese context and provides important cross validation of results.

Landpflanzen nehmen auf drei Wegen Einfluss auf die klimatischen Verhaltnisse: uber Veranderungen der Strahlungsbilanz, der Stoffkreislaufe und des Impulsaustausches. Beispiele aus der Erdgeschichte zeigen, wie gros dieser Einfluss der Vegetation auf das Klimageschehen sein kann. Im Karbon fuhrte offensichtlich die Besiedlung des Festlandes durch Pflanzen zur Entwicklung eines Eishausklimas mit ausgedehnter Vereisung. Umgekehrt erlaubte zu Zeiten von Treibhausklimaten mit hohen CO2-Konzentrationen die Ausbreitung der Walder bis in hohe Breiten erst die Entwicklung eines global relativ ausgeglichenen Klimas mit warmen und eisfreien Polarregionen. Fur alle Modelle, die das Klima der kommenden Jahrzehnte berechnen sollen, ist diese Wechselwirkung von entscheidender Bedeutung.

In terms of climate, the Late Miocene represents a transitional phase between the Eocene greenhouse climate and the Quaternary icehouse situation; it is characterised by an extensive Antarctic ice sheet and incipient glaciation in the Northern Hemisphere. In order to better understand the Late Miocene climate, we performed a simulation study for the Tortonian using the complex atmospheric general circulation model ECHAM4 coupled to a mixed-layer ocean model. The boundary conditions such as the orography and the continental ice distribution were adapted to the Tortonian conditions; considering the coarse geographic resolution of the model, the land–sea distribution was assumed to be similar to the present situation and the atmospheric CO 2 concentration was set to 353 ppm. Because the mixed-layer ocean model uses a flux correction tuned to the modern oceanic heat transport a method was developed to estimate the Tortonian palaeo-flux correction based on the zonally averaged SST gradients. As compared to the present-day world, the Tortonian model run shows a significant reduction in the oceanic heat transport, a considerable warming and reduction of sea ice in high latitudes, a weakening of the Asian monsoon, a cooling in the mid-latitudes–caused by the reduced oceanic heat transport–and an increase in precipitation in Southern Europe. Except for the cooling of the mid-latitudes these results are largely consistent with proxy-data and other modelling studies although the proxy data indicate much warmer conditions in high latitudes than calculated in the model. The reasons for the discrepancies between model-based and proxy data reconstructions are discussed.

International audience; A mutual climatic range method is applied to the Mediterranean marine pollen record of Semaforo (Vrica section, Calabria, Italy) covering the period from ∼2.46 Ma to ∼2.11 Ma. The method yields detailed information on summer, annual and winter temperatures and on precipitation during the nine obliquity and precession-controlled ‘glacial’ periods (marine isotope stages 96 to 80) and eight ‘interglacial’ periods (marine isotope stages 95 to 81) characterising this time interval. The reconstruction reveals higher temperatures of at least 2.8 °C in mean annual and 2.2 °C in winter temperatures, and 500 mm in precipitation during the ‘interglacials’ as compared to the present-day climate in the study area. During the ‘glacials’, temperatures are generally lower as compared to the present-day climate in the region, but precipitation is equivalent. Along the consecutive ‘interglacials’, a trend toward a reduction in annual and winter temperatures by more than 2.3 °C, and toward a higher seasonality is observed. Along the consecutive ‘glacials’, a trend toward a strong reduction in all temperature parameters of at least 1.6 °C is reconstructed. Climatic amplitudes of ‘interglacial–glacial’ transitions increase from the older to the younger cycles for summer and annual temperatures. The cross-spectral analyses suggest obliquity related warm/humid–cold/dry ‘interglacial–glacial’ cycles which are superimposed by precession related warm/dry– cold/humid cycles. A time displacement in the development of temperatures and precipitation is indicated for the obliquity band by temperatures generally leading precipitation change at ∼4 kyr, and on the precession band of ∼9.6 kyr in maximum

Jurassic deposits are well exposed in the Qaidam Basin, Qinghai Province, northwest China, and are regarded as one of the most completely developed Early–Middle Jurassic plant-bearing sequences in northern China. The Early to Middle Jurassic palynoflora in this basin shows a high diversity of spores and pollen grains, which are characterized by four palynological assemblage zones corresponding to the Pliensbachian, Toarcian, Aalenian–Bajocian and Bathonian in age. Vegetation reconstruction demonstrates four vegetation types: upland coniferous forest in the Pliensbachian, coastal cheirolepidiacean forest in the Toarcian, lowland fern forest in the Aalenian–Bajocian and a mixed forest in the Bathonian. Nearest living relative analysis of the major plant groups shows that the Early to Middle Jurassic vegetation in the Qaidam Basin not only consists of plants with tropical–subtropical climate requirements, but also those indicating temperate climatic conditions. In addition, bryophytes and fungi as well as Cheirolepidiaceae, which are generally considered to indicate warmer and/or drier conditions, are also documented in the palynofloras. It is suggested that a temperate to subtropical climate generally prevailed during the Early to Middle Jurassic in this basin. However, the vegetation features and the sedimentary data signify that an overall humid to semi-humid phase was punctuated by warmer and locally dry and/or arid episodes. The two higher temperature and aridity events occurred in the Toarcian and Bathonian-Callovian periods in the Qaidam Basin. These climatic events can be inferred by increase of relative abundance of Classopollis pollen, some tropical–subtropical fern spores, and the occurrences of variegated, red beds and evaporite rocks. These events may either be associated in some way with a transient global warming phenomenon due to an enhanced greenhouse effect, or be linked with intensification of a potential monsoonal circulation. Such events finally caused a weakening and even arrested coal-accumulation in the Qaidam Basin during the Toarcian and the Bathonian-Callovian intervals.

Holocene coastal environmental changes are interpreted from a 590 cm long core taken from Itapeva Lake in the northern coastal plain, Rio Grande do Sul, Brazil. The sediment core is radiocarbon dated at 211 cm depth (6460±40 yr B.P.) and studied by geochemistry and palynomorph analyses. The Pleistocene–Holocene boundary is predicted at the top of a glauconitic sand layer at 330 cm depth. On the basis of C org , N, S, and palynomorph data, it is possible to distinguish four zones related to the Holocene transgression–regression cycle, as well as proxies for the salinity trends and organic matter source. The start of Zone 1 represents the oldest Holocene sedimentary record in the core. Palynomorphs reveal a marsh environment with a freshwater influence. In Zone 2, Operculoclinium centrocarpum and high S values indicate brackish water and reflect a Holocene sea-level rise related to the postglacial marine transgression. The high amount of Cyperaceae pollen grains and a significant C org increase in Zone 3 indicate a typical marsh environment with episodes of marine water that reflect a regression phase. Salvinia natans (L) All. and Cyperaceae pollen grains are the most significant palynomorphs in Zone 4, which characterizes a freshwater marsh.

Sphenobaiera huangii (Sze) Hsü is typical Early Mesozoic fossil foliage of Ginkgoales in China. It has been recorded from the Upper Triassic to the Lower Jurassic. The cuticular anatomy is investigated based on material from the type locality, Lower Jurassic Hsiangchi Formation, Zigui County, Hubei Province. The specimens are similar to S. huangii, but contain new information about leaf morphology and cuticular anatomy. Lower and upper cuticle is investigated using light and electron microscopy (LM, SEM, and TEM). Many features are described for the first time, including general structures of lower and upper cuticle, stomata, papillae, and cuticular ultrastructure. At the ultrastructural level, two layers have been distinguished in both lower and upper cuticle, including a homogeneous outer layer with granules and a heterogeneous inner layer with fibrils. Based on a literature comparison between S. huangii and other relevant species of Sphenobaiera, S. huangii may represent the best-known taxon in the genus Sphenobaiera in both leaf morphology and cuticular structures. This study provides the first detailed ultrastructural data on the leaf cuticle of Sphenobaiera, one of the oldest foliage taxa of Ginkgoales, and offers further evidence for potential discussion on the taxonomic relationships of S. huangii with other ginkgoalean taxa.

High-resolution pollen records from the northern alpine foreland are used to evaluate the patterns of climate change during the period between the late Eemian Interglacial (marine oxygen isotope stage OIS 5e) about 115 ky ago and the end of the St. Germain II (OIS 5a, Dansgaard–Oeschger interstadial D/O IS21) about 75 ky ago. For the quantitative climate interpretation of the fossil pollen assemblages, we compare two different methods, a modern analogue technique and a mutual climatic range approach. The results not only reveal major climatic changes at the transition to stadials and interstadials, but also indicate short-term oscillations which are followed by an almost full return to the preceding climate conditions, and components of gradual trends resembling saw-tooth structures. Based on the pollen data, the climate reconstructions suggest that the optimum in St. Germain II (OIS 5a, D/O IS21) in winter temperatures was about 0.8 to 1.4 °C and in summer temperatures about 0.7 to 1.2 °C warmer than the optimum in St. Germain I (OIS 5c, D/O IS22 to IS24). The severe and short-time Montaigu cold event (iceberg discharge event C23) clearly divided St. Germain I into two thermal periods. Thus, St. Germain Ia (D/O IS24) preceding the Montaigu event is slightly more favourable than the following St. Germain Ic (D/O IS23). Since several climate oscillations occurred during these interstadials, they show only limited stability. With respect to the stadial periods, the results reveal a coherent pattern for all records. Winter temperatures during Melisey II (OIS 5b, C21) are about 1 to 4 °C lower than those during Melisey I (OIS 5d, C24). As regards short-term climate changes during Melisey I and Melisey II, consistent amelioration episodes may be distinguished during these intervals.

The Smrekovec Tertiary (Slovenia) represented an important marine connection between the Tethys Ocean and the developing Paratethys. The Paleogene sequence rests unconformably on Permotriassic rocks of the Southalpine Kamnik Alps. It starts with Eocene terrigenous sediments and marine carbonates grading into Oligocene shallow marine sediments. After an increasing deepening of the environment, explosive eruptions of the Smrekovec volcano to the N led to the deposition of thick volcaniclastics. The calc-alkaline volcanic rocks and their associated volcaniclastics are of andesitic to (rhyo)dacitic composition. Volcanic activity lasted from Rupelian until Chattian (if not earliest Miocene) times. The present appearance of the Smrekovec Tertiary is interpreted to result from late-Alpine tectonics along the Periadriatic Fault possibly representing a pull-apart or extensional duplex structure within the Permotriassic succession of the Kamnik Alps. It is thus an erosional remnant of a former larger depositional area and did not have the form of the present basin around Smrekovec in Paleogene times.

In the present study, proxy data concerning changes in atmospheric CO2 and climatic conditions from the Late Eocene to the Early Miocene were acquired by applying palaeobotanical methods. Fossil floras from 10 well-documented locations in Saxony, Germany, were investigated with respect to (1) stomatal density/index of fossil leaves from three different taxa (Eotrigonobalanus furcinervis, Laurophyllum pseudoprinceps and Laurophyllum acutimontanum), (2) the coexistence approach (CA) based on nearest living relatives (NLR) and (3) leaf margin analysis (LMA). Whereas the results of approach (1) indicate changes in atmospheric CO2 concentration, approaches (2) and (3) provide climate data. The results of the analysis of stomatal parameters indicate that the atmospheric CO2 concentration was higher during the Late Eocene than during the Early Oligocene and increased towards the Late Oligocene. A lower atmospheric pCO2 level after the Late Eocene is also suggested by an increase in marine palaeoproductivity at this time. From the Late Oligocene onwards, no changes in atmospheric CO2 concentration can be detected with the present data. For the considered sites, the results of the coexistence approach and of the leaf margin analysis document a significant cooling event from the Late Eocene to the Early Oligocene. The pCO2 decrease from the Late Eocene to the Early Oligocene indicated by the stomatal data raised in this study was thus coupled to a temperature decrease which is reflected by the present datasets. From the Early Oligocene onwards, however, no further fundamental climate change can be inferred for the considered locations. The pCO2 increase from the Early Oligocene to the Late Oligocene, which is indicated by the present data, is thus not accompanied by a climate change at the considered sites. A warming event during the Late Oligocene is, however, recorded by marine climate archives. According to the present data, no change in pCO2 occurred during the cooling event at the Oligocene/Miocene boundary, which is also indicated by marine data. The quality and validity of stomatal parameters as sensors for atmospheric CO2 concentration are discussed.

The Miocene Shanwang biota from eastern China contains exceptionally well-preserved plant fossils with abundant leaf fossils and palynomorphs co-occurring at several levels in the sedimentary succession. This has provided an ideal opportunity to undertake detailed comparative quantitative palaeoclimate reconstruction, based on both mega- and microfloral assemblages, using various approaches, namely the coexistence approach (CoA), leaf margin analysis (LMA) and Climate Leaf Analysis Multivariate Programme (CLAMP). By applying these approaches to the same dataset and using multiple fossil assemblages from different levels we are able to compare results from the different methods of climate prediction. CLAMP and LMA give consistently lower temperature (mean annual temperature, MAT) predictions than the CoA. Taking errors into account all methods indicate no overall climate change through the sequence studied. Results from CoA show overall agreement in the palaeoclimate parameters obtained using both pollen and leaf datasets indicating a high degree of internal consistency with this method.

International audience; Analyses of Eemian climate dynamics based on different reconstruction methods were conducted for several pollen sequences in the northern alpine foreland. The modem analogue and mutual climate sphere techniques used, which are briefly presented, complement one another with respect to comparable results. The reconstructions reveal the occurrence of at least two similar thermal periods, representing temperate oceanic conditions warmer and with a higher humidity than today., Intense changes of climate processes become obvious with a shift of winter temperatures of about 15degreesC from the late Rissian to the first thermal optimum of the Eemian. The transition shows a pattern of summer temperatures and precipitation increasing, more rapidly than winter temperatures. With the first optimum during the Pinus-Quercetum mixtum-Corylus phase (PQC) at an early stage of the Eemian and a second optimum period at a later stage, which is characterised by widespread Carpinus, climate gradients across the study area were less intense than today. Average winter temperatures vary between -1.9 and 0.4degreesC (present-day -3.6 to 1.4degreesC), summer temperatures between 17.8 and. 19.6degreesC, (present-day 14 to 18.9degreesC). The timberline expanded about 350 m when compared to the present-day limit represented by Pinus mugo. Whereas the maximum of temperature parameters is related to the first optimum, precipitation above 1100 mm is higher during the second warm period concomitant to somewhat reduced temperatures. Intermediate, smaller climate oscillations and a cooling becomes obvious, which admittedly represent moderate deterioration but not extreme chills. During the boreal semicontinental Eemian Pinus-Picea-Abies phase, another less distinct fluctuation occurs, initiating the oscillating shift from temperate to cold conditions. (C) 2003 Elsevier Science B.V All rights reserved.

An Oligocene succession from the Slovenian Sava Basin (Zasavje) was analysed to reconstruct climate and vegetation of the interval. Independent quantitative approaches were applied on a detailed palynological data set to reconstruct both parameters separately allowing for a synthesis and interpretation. The reconstruction of palaeoclimate is based on the coexistence approach and documents an equal, warm-temperate, humid climate with low annual variation. Quantitative results indicate values of mean annual temperature of 16–19°C, with winter temperatures of 6–9°C and summer temperatures of 25–28°C, and a mean annual precipitation ranging between 1100 and 1300 mm. In contrast to the very homogeneous climatic signal, the vegetational reconstruction based on multivariate statistical analyses shows distinct changes through time. During intervals of peat accumulation, the environment was a typical swamp vegetation dominated by Taxodiaceae and ferns, in which ephemeral small ponds developed due to changing groundwater levels. With the development of an expanded limnic environment, the Taxodiaceae retreated and a riparian swamp flora dominated. This vegetation, in turn, was displaced by elements of drier mesophytic habitats that increased in abundance during a tectonically forced lowering of the groundwater table. Subsequently, the entire study area was flooded by transgression and overlain by marine sediments. All changes in vegetation can be explained by influences of the basin development on the habitats of the plant communities. The results demonstrate a vegetational change in the Oligocene of the Sava Basin that is independent from climate. Vegetation change dynamics were controlled probably by the regional tectonic–palaeogeographic development within a very equable, warm-temperate, and humid climate.

Based on recent studies, the impact of global sea-level and climate change on the paleogeographic and sedimentary evolution of the Tertiary of the Lower Rhine Basin is analysed. It is shown that major changes in global climate and sea-level, such as the high-stand during the Middle Miocene climate optimum, the extreme low-stands near the base of the Tortonian and within the Messinian, are clearly reflected in the sedimentary succession. Continental climate curves, as reconstructed from Tertiary macrofloras of the Lower Rhine Basin, can be correlated with the marine, long-term isotope record. As shown by the analyses, a warm and humid climate with mean annual temperatures above 13°C and mean annual precipitation not below 1000 mm, persisted throughout the Late Miocene to Early Pliocene. Continental, high-resolution, climate data show that Late Miocene alternations of lignites and elastics are rather caused by tectonic and sedimentary processes (such as the repeated migration of the river system) than by major climate changes.

The potential of fossil wood and charcoal from browncoal deposits as sources of reliable paleoenvironmental information is explored with material from the Lower Rhine Embayment (Germany). The presence of charcoalified material demonstrates proof of natural wildfires in Tertiary mire environments, most probably during, or after periods of increased drainage and drying of surface vegetation and litter. The results presented suggest that sampling from charcoal layers may provide a more statistically reliable data set for study of such environments. Inclusion of taxa recovered from charcoal layers might compensate for the taphonomic and preservational bias of Tertiary lignitic floras based solely on the collection of lignitic wood. These data confirm the hypothesis that, during certain intervals of the Miocene, both monocotyledonous and dicotyledonous angiosperms might have dominated or represented significant portions of the peat-forming vegetation. The importance of palms and shrubby woody taxa, such as ‘Cyrilla’, is particularly striking from new evidence of charcoalified remains. In addition, certain wood anatomical features observed from well preserved lignitic wood and charcoal may be used as indicators of environmentally modulated growth: (1) clear growth rings testify to the existence of a seasonal climate; (2) wide variations in growth ring characters indicate variable environmental conditions; and (3) high incidence of dicotyledonous taxa, with abundant small vessels and scalariform perforation plates, is interpreted as evidence of a mesic environment.

We reconstruct quantitatively the Middle to Upper Miocene climate evolution in the southern Forecarpathian Basin (Central Paratethys area, Northwest Bulgaria) by applying the coexistence approach to 101 well-dated palynofloras isolated from three cores. The climatic evolution is compared with changes in vegetation and palaeogeography. The Middle Miocene was a period of a subtropical/warm–temperate humid climate with mean annual temperature (MAT) between 16 and 18°C and mean annual precipitation (MAP) between 1100 and 1300 mm. Thereby, during the entire Middle Miocene a trend of slightly decreasing temperatures is observed and only small climate fluctuations occur which are presumably related to palaeogeographic reorganisations. The vegetation shows a corresponding trend with a decrease in abundance of palaeotropic and thermophilous elements. The Upper Miocene is characterised by more diverse climatic conditions, probably depending on palaeogeographic and global climatic transformations. The beginning of this period is marked by a slight cooling and a significant drying of the climate, with MAT 13.3–17°C and MAP 652–759 mm. After that, fluctuations of all palaeoclimate parameters occur displaying cycles of humid/dryer and warmer/cooler conditions, which are again well reflected in the vegetation. Our study provides a first quantitative model of the Middle–Upper Miocene palaeoclimate evolution in Southeastern Europe and is characterised by a relatively high precision and resolution with respect to the climate data and stratigraphy.

The leaves of extant terrestrial plants show highly diverse and elaborate patterns of leaf venation. One fundamental feature of many leaf venation patterns, especially in the case of angiosperm leaves, is the presence of anastomoses. Anastomosing veins distinguish a network topologically from a simple dendritic (tree-like) pattern which represents the primitive venation architecture. The high degree of interspecific variation of entire venation patterns as well as phenotypic plasticity of some venation properties, such as venation density, indicate the high selective pressure acting on this branching system. Few investigations deal with functional properties of the leaf venation system. The interrelationships between topological or geometric properties of the various leaf venation patterns and functional aspects are far from being well understood. In this review we summarize current knowledge of interrelationships between the form and function of leaf venation and the evolution of leaf venation patterns. Since the functional aspects of architectural features of different leaf venation patterns are considered, the review also refers to the topic of individual and intraspecific variation. One basic function of leaf venation is represented by its contribution to the mechanical behaviour of a leaf. Venation geometry and density influences mechanical stability and may affect, for example, susceptibility to herbivory. Transport of water and carbohydrates is the other basic function of this system and the transport properties are also influenced by the venation architecture. These various functional aspects can be interpreted in an ecophysiological context.

A new approach is proposed to obtain quantitative temperature reconstructions from Early and Middle Pleistocene pollen and megafloral records. Utilizing the indicator species concept pioneered by Iversen (1944, Geologiska Foreningen Forhandlingar Stockholm 66, 463–483), the new methodology overcomes the problem of non-analogue plant communities by only taking into account the presence/absence of taxa rather than their relative abundances. Based on the present day thermal tolerances of the taxa from a fossil assemblage, the temperature interval in which all taxa from this assemblage can coexist is determined. A databank containing the climate tolerances of 85 taxa from European pollen records was established. To increase the temperature resolution of the method, procedures were developed to assess the most likely intervals for the actual temperatures within the calculated common thermospheres and the routine evaluation of the mean temperatures of the warmest and coldest months (MTW and MTC). After calibrating the approach on modern assemblages, it was applied to Tiglian and Holsteinian pollen sequences from Lieth (northern Germany) and Lac du Bourget (northern French Alps). For both records the method yields detailed temperature reconstructions of temperate and cold episodes. During the coldest episode of the Lieth section, the MTC may have been as low as −16°C. Corresponding MTW values range from 14.5 to 21°C, thus testifying to a strong continentality at that time. During the warmest period reconstructed for the Lieth section, the MTC was similar to the value as measured in the area today (1.5°C), whereas the MTW was probably higher than at present (20.1°C). For the coldest interval from the Lac du Bourget pollen sequence, the reconstructed MTC values reach a minimum of −15°C. Corresponding MTW values range from 15 to 22°C, again implying a strong continentality. For the warmest period our approach yields MTC values between −2 and 2°C and MTW values between 16.5 and 22°C. For both records, the resolution for the MTW and MTC reaches 1.5 and 2.5°C, respectively.

Identification of charcoal fragments (≥2 mm) using reflected light microscopy is routinely carried out to study former natural ecosystems, assess changes in vegetation communities over time and identify the influence and patterns of behaviour of human populations on vegetation. Material studied comes either from archaeological horizons or soil profiles. Despite undeniable limits, informative results have been obtained in the last 25 years, mostly in southwestern Europe, where charcoal analysis has been widely applied in Quaternary studies. Examples of these achievements are provided, focusing on the major vegetation trends since the Upper Palaeolithic to the Middle Ages. The techniques used for charcoal analysis in the reconstruction of Quaternary vegetation are now being used to study Tertiary charcoal and lignites. The study of fossil charcoal can be a highly informative method for interpreting ancient ecosystems as species easily degraded may be preserved by charcoalification. Some results from the Lower Rhine Embayment (Germany) are presented here.

The first detailed reconstruction of the continental paleoclimate evolution of the Northwest German Tertiary (Late Oligocene to Pliocene) is presented. The paleoclimate data are derived from the paleobotanical record using the coexistence approach, a method recently introduced that employs climatic requirements of the Nearest Living Relatives of a fossil flora. Twenty six megafloras (fruits and seeds, leaves, woods) from the Tertiary succession of the Lower Rhine Basin and neighboring areas are analyzed with respect to ten meteorological parameters. Additionally, two sample sets from Late Miocene to Early Pliocene sediments comprising 396 palynofloras are analyzed by the same method providing a higher temporal resolution. The temperature curves show a comparatively cooler phase in the Late Oligocene, a warm interval the Middle Miocene, and a cooling starting at 14 Ma. The cooling trend persisted until Late Pliocene with a few higher frequency temperature variations observed. From the beginning of Late Miocene to the present, the seasonality increases and climate appears to have been less stable. As indicated by the precipitation data, a Cfa climate with wet summers persisted in NW Germany from Late Oligocene to Late Pliocene. The results obtained are well in accordance with regional and global isotope curves derived from the marine record, and allow for a refined correlation of the Tertiary succession in the Lower Rhine Basin with the international standard. It is shown that the reconstructed data are largely consistent with the continental climate record for the Northern Hemisphere, as reported by various authors. Discrepancies with previous reconstructions are discussed in detail.

Several sections from the uppermost Eocene and Oligocene of northern Slovenia have been investigated with respect to sedimentary facies, foraminiferal assemblages, stable isotopes, carbonate microfacies, and palynology. The main objective was to reconstruct the paleoenvironmental history of the Paleogene Paratethys in this region of the eastern Alpine realm. The sediments exhibit a transgressive succession beginning with conglomerates, sandstones, and mudstones of fluvial and lacustrine origin followed by carbonates and muddy marls indicating marine conditions. The foraminiferal faunal changes from brackish to shallow marine to deeper marine assemblages and the distribution of the palynofloras corroborate the sedimentological results. Microfacies analysis of the limestones shows a wide variation of shallow water, generally mud-rich facies dominated by coralline algae, foraminifera, and corals. Microfaunas adapted to low-oxygen conditions indicate temporal sluggish bottom-water circulation which can be associated with high fresh-water fluxes. These results are discussed as reflecting both the global sea-level rise during the Early Oligocene and the regional tectonic and climatic evolution.

Buchenblatter, die auf Grund starken multiplen Stresses eine Aberration des Aderungsmusters aufweisen, werden morphologisch beschrieben. Die Ahnlichkeit der aberranten Aderungsmuster zu phylogenetisch alteren Fagaceen-Gattungen wird diskutiert und auf die Moglichkeit solcher Aberrationen im Fossil-Beleg hingewiesen. Stress induced aberrations of the leaf venation in beech (Fagus sylvatica L.) – Short communication Aberrations of leaf venation in beech leaves, caused by multiple stress, are described morphologically. Similarities between these aberrations and phylogenetically older genera of the Fagaceae are discussed and the possibility of such aberrations in the fossil record is mentioned.

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.

A new method in palaeoclimatology, initially proposed by Mosbrugger and Schilling (1992) , which makes it possible to extract a maximum of information from the available proxy-data is tested. It possesses a capacity to produce a detailed palaeoclimate reconstruction, which is consistent with both proxy-data and the physics of atmospheric models. Since proxy-data information is particularly poor on a global scale, our method focuses on smaller-scale regions of better proxy-data coverage. It consists of an iterative coupling of inverse mesoscale atmospheric modelling with proxy-based palaeoclimate reconstruction. Using this method, the palaeoclimate of the Tortonian (Upper Miocene) of the Lower Rhine Embayment (northwest Germany) is reconstructed with a high spatial resolution. The results include a physically consistent inter- and extrapolation of proxy-derived palaeoclimate data in space and onto variables not accessible from geological–palaeontological proxies alone. Moreover, the method delivers statistics of the large-scale atmospheric flows as information on the coupling of the regional climate to global fields.

In palaeobotany, leaf venation density is still primarily used as a taxonomic character although numerous studies on recent plants reveal that leaf venation density may be influenced by various environmental factors. To promote the use of leaf venation density as a palaeoclimate/palaeoenvironmental proxy we give a brief review of these studies and provide some additional data. Our review shows that environmental factors that increase transpiration of plants or decrease water availability also tend to increase the leaf venation density. Based on the analysis of leaves of some recent and fossil plants we found: (1) Venation density may be measured as vein length per area or as distance between veins, but the first parameter is more reliable. (2) Depending on the plant species, leaf venation density may or may not vary with leaf size. This `leaf size effect' has to be taken into account when leaf venation density is to be used as a palaeoclimate/ palaeoenvironmental proxy. (3) No significant effect of a changing atmospheric carbon dioxide concentration on leaf venation density was observed. (4) In Permian seed plants, intraspecific variation of leaf venation density was similar to that observed in modern angiosperms. Obviously, even in these seed plants, leaf venation density can be used as a palaeoclimate/palaeoenvironmental proxy.

New methods of sampling, preparing and identifying fossil wood fragments preserved in browncoal are presented and used to aid in reconstructions of the vegetation from the Miocene Lower Rhine Basin (Germany). The technique involves laboratory charring wood specimens followed by routine identification with reflected light microscopy. Problems concerning the taxonomic identification of the fossil wood are discussed. A list of taxa is presented for the Garzweiler Seam and the implications for reconstructing the Miocene palaeoenvironment are discussed with reference to ecological comparisons of extant taxa: the nearest living relative approach. Results indicate a dominance of conifer wood types, mostly representing members of the Taxodiaceae and Cupressaceae; extensive sampling is required of both small (macroscopic) and large fragments to obtain results comparable with palynological assemblages. Up to now, twenty-one taxa of gymnosperms and angiosperms have been recognized from the Garzweiler seam. Data obtained are compared with those from pollen analysis and corroborate the previously identified trend consisting of increasing concentrations of Taxodium towards the upper section of the seam.

The analyses of the form–function relationship in plant water transport systems are severely restricted due to several factors: (1) It is almost impossible to directly observe the water flow in single components of the xylem: tracheids or vessels. (2) The water relations of tissues or whole plant organs are difficult to measure experimentally. (3) Systematic comparative studies of various xylem constructions are severely hampered by individual variations in morphology as well as by the complex pattern of physiological reactions of living plants. (4) Finally, direct experimental work on fossil plants is obviously impossible. Here, numerical modelling is provided as an alternative to experimental studies. Computer simulations have the following advantages and possibilities. (1) The different levels of xylem organization, conduits or conducting bundles and systems of conducting bundles, can be modelled by appropriate physical models. (2) Systematic parameter variations are easily accomplished. The consideration of arbitrary architectures is possible and, thus, a direct comparison of various xylem architectures. (3) High resolution results on the spatial as well as the temporal level can be obtained. (4) The evolutionary process can be simulated with the approach of synergetics (a mathematical theory which describes self organization processes) allowing form–function relationships to be tested. In this paper some numerical studies of the water transport properties of telomes with various stele types to provide a functional explanation for observed patterns of stelar evolution are presented. It is demonstrated that water transporting function is the crucial factor in the evolution of the various steles. Three geometric parameters which determine the water transport performance and the water transport efficiency of transpiring plant axes are identified. These geometric parameters provide the basis for a functional explanation of the evolution of the stele. Using the approach of phenomenological synergetics the stelar evolution itself is simulated as system state transitions induced by water supply demands of the axis.

The coexistence approach is introduced as a method for quantitative terrestrial palaeoclimate reconstructions in the Tertiary. It is based on the assumption that Tertiary plant taxa have similar climatic requirements to their nearest living relatives. The aim of the coexistence approach is to find for a given fossil flora and a given climate parameter the climatic interval in which all nearest living relatives of the fossil flora can coexist. For this purpose we have developed a data base, CLIMBOT (containing for over 800 Tertiary plant taxa, the nearest living relatives and their climatic requirements) and an algorithm for analysis, CLIMST. For all types of fossil floras the coexistence approach thus allows the rapid quantitative reconstruction of 10 different climate parameters, including the mean annual temperature, temperature of the warmest month, temperature of the coldest month, mean annual precipitation, maximum monthly precipitation, minimum monthly precipitation, precipitation of the warmest month, relative humidity, potential evaporation, as well as the ratio of mean annual precipitation over potential evaporation. The reliability and resolution of the coexistence approach are tested with various techniques and proved to be reasonably good; for instance, the resolution with respect to the mean annual temperature can be up to 1°C. Applications to various modern and fossil floras are illustrated and the advantages and disadvantages of the coexistence approach are discussed.

A detailed stable carbon isotopic profile of a late Miocene browncoal seam from the Lower Rhine Embayment, Germany, reveals two clear separate cycles of different frequency: this is the first instance of this type of isotopic signature being recognized within coals. The ratio of the two frequencies suggests this isotopic signal possibly resulted from climatic or vegetational responses to orbital forcing. The cyclicity has been enhanced by the application of conventional filtering methods on the data set. An analysis of the seam’s palynology indicates a correlation between heavier isotopic compositions and the presence of Sequoiapollenites polyformosus, whose parent plant is believed to have favoured moist climates and higher groundwater tables.

During land plant evolution, a change in stelar architecture, i.e., in the geometric arrangement of the water-conducting tissue inside the plant axis, can be observed. In the most primitive stele type, the protostele, the vascular tissue is organized as a simple central strand. Further evolutionary changes led to more peripherally arranged vascular tissues. In the siphonostele, for example, the vascular tissue forms a hollow cylinder filled with pith. A functional explanation of this early stelar evolution is provided in the present paper. Using a numerical simulation approach, we analyze the water transport properties of various protostelic and siphonostelic model axes. The results indicate that several geometric parameters are relevant for understanding the water transport properties of various stele types and for explaining the early stelar evolution: the parenchymatic path lengths (i.e., the distance between the xylem surface and the transpiring plant surface), the ratio of xylem surface over transpiring surface, and the ratio of cross-sectional area of xylem to cross-sectional area of the parenchyma outside of the xylem. As a whole, the evolution of early stele types may be viewed as a size-related multi-criteria optimization process in which the xylem volume as well as the fluid pressure gradients in the parenchyma and in the xylem are minimized. For slender plant axes, a protostele appears to be the optimal stelar architecture. In wider plant axes, however, other stelar architectures (such as a siphonostele) prove to be more efficient than a protostele.