Palynologie

Because of their small size and vast abundance in various types of sedimentary rocks, microfossils have found a multitude of applications in geology, especially regarding biostratigraphy, correlations and paleoenvironmental analysis. Organic-walled microfossils such as pollen, spores, and various organic debris derived from terrestrial plants, are especially useful when studying terrestrial deposits. This chapter presents the many different groups of organic-walled microfossils, collectively called palynomorphs, and the different methods palynologists use to study and extract them from sediments and rocks. We present a biostratigraphic application, the use of the pollen and spore record across the Cretaceous–Paleogene boundary, which has proven to be one of the most precise and reliable means for pinpointing this major transition within terrestrial deposits.

Traditional leafy vegetables represent inexpensive but high quality nutritional sources,
for the poor segment of the population especially where malnutrition is wide spread. The
objectives of this research were a) to identify and document the traditional leafy
vegetables and spices of Ebonyi State, and b) to assess their nutritional values with a
view of enhancing their selection as components of cooked food. Market and field
surveys were carried out for traditional leafy vegetables and spices in three major clans
in Ebonyi North senatorial zone, Ebonyi State: Izzi, Izhia and Ngbo clans. Informal
interviews were also conducted with some indigenes on the vegetables and spices
identified, including where, when and how they were obtained for sale in the markets.
Finally, proximate and Mineral content analysis of three of the traditional leafy
vegetables was done to know their nutritional as well as mineral content. Results
identified twenty-seven traditional leafy vegetables and five spices from 23 plant
families. 46.7 % of the plant collections were seen and collected from the wild, while 40
% were cultivated. 33.3 % of the leafy vegetables were tree species, 30 % were
herbaceous plants, and 23 % were climbers, while 13.3 % were shrubs. 60 % of the
species were propagated by seed, while 36.7 % were propagated by vegetative means.
The parts consumed were mainly the leaves (76.7 %), the stem, flower and the seeds. 40
% of the materials collected were major income earners for the rural populace, 36.7 %
earned some income, although small, while 23.3 % had the potential of being
transformed into large scale income earner. Results also indicated that three of the
vegetables analysed were good sources of micro-nutrients. Their calcium content ranged
between 54.06 - 90.10 mg/100 g, while zinc and lead which are antioxidants were
absent. The ash content of the three plants ranged from 8.10 - 6.30 %, while protein
ranged from 5 – 10 % of fresh weight or 13 - 30% for dry weight. Their fiber (roughage)
content was high and will promote digestion and prevent constipation when consumed.

This study provides a detailed reconstruction of the paleoenvironmental conditions that prevailed during one of the periods of modern human migration out of Africa and their occupation of the Eastern Mediterranean-Levant during the Late Middle Paleolithic-Early Upper Paleolithic. Tracing the past vegetation and climate within the Eastern Mediterranean-Levant region is largely based on a southeastern Mediterranean marine pollen record covering the last 90 kyr (core MD-9509). The various palynomorphs were linked to distinct vegetation zones that were correlated to the two climate systems affecting the study area: the low-latitude monsoon system and the North Atlantic-Mediterranean climate system. The bioprovince palynological markers show that during the period between ~56 and 44 ka, which covers the early part of Marine Isotope Stage 3 (MIS 3), there was an increase in transportation of pollen from Nilotic origin and a rise in dinoflagellate cyst ratios. These changes coincided with maximum insolation values at 65 N, which led to an enhancement in Nile River discharge into the Eastern Medi-terranean following the intensification of the African monsoonal system. At the same time, the rise in Mediterranean arboreal pollen values (broadleaved, coniferous and deciduous temperate trees) is most likely driven by increased precipitation related to the intensification of the North Atlantic-Mediterranean climate system. The ~56e44 ka wet event coincides with Dansgaard-Oeschger interstadials 14 and 12 and with a warming phase in the Levant, as evidenced by the melting of permafrost along the higher elevations of Mount Hermon. We suggest that African modern humans were able to cross the harsher arid areas due to the intensification of the monsoonal system during the first part of MIS 3, and inhabit the Eastern Mediterranean-Levant region where climatic conditions were favorable (wetter and warmer), even in the currently semiarid/steppe regions.

Middle Miocene deposits exposed at the Tınaz lignite mine, Yatağan Basin, Muğla, southwestern Turkey, were palynologically investigated. The Tınaz lignite mine section belongs to the Eskihisar Formation. The lignite seam at the base of the section represents the uppermost part of the Turgut Member. Above, c. 65 m of clayey siltstone, limestone, and marls represent the Sekköy Member. Nine spores, zygospores and cysts of fungi and algae, seven moss and fern spores, 12 gymnosperm pollen types, and more than 80 angiosperm pollen taxa were recovered from the Tınaz lignite mine section. Three pollen zones were recognized, of which pollen zone 1 corresponds to the formation of the main lignite seam and reflects the change from a fluviatile to a lacustrine depositional setting. Pollen zones 2 and 3 and a transitional zone 2-3 reflect different stages of lake development and a shift in local vegetation from forested (pollen zones 1 and 2) to more open (transitional zone 2-3, zone 3). Interpreting changes in regional vegetation from pollen zones 1 to 3 is not straightforward as changes in the pollen spectra may be affected by changing contributions of airborne and water transported pollen and spores to the observed palynoassemblages. Age inference for the Tınaz lignite mine section has been complicated by the absence of datable ash layers, associated mammal faunas, or marine sediments. However, pollen zone 3 shares key features with the pollen spectrum recovered from the nearby mammal site Yenieskihisar (upper part of Sekköy Member) for which an age of 12.5-11.2 Ma has been suggested, and to the youngest pollen zone recovered from the mammal locality Çatakbağyaka, 10 km south of Tınaz, that probably represents mammal zone MN7/8 instead of MN5 or MN6 as previously suggested. In contrast, pollen zones 1 and 2 are fairly similar to the basal parts of the Çatakbağyaka pollen flora (uppermost parts of Turgut Member, basalmost parts of Sekköy Member). Furthermore, new mammal data from the Yatağan basin suggest that the layers below pollen zone 1 are MN4/5, and that carnivores cooccuring with pollen zone 1 in the main lignite seam of Eskihisar probably belong to MN6. Hence, a Langhian to Serravallian age can be inferred for pollen zones 1 and 2 of the Tınaz lignite mine section, and a late Serravallian age for pollen zone 3. Palaeobiogeographic relationships of the palynofloras are generally northern hemispheric, with many north temperate tree taxa showing modern disjunctions East Asia- NorthAmerica (Tsuga, Carya), East Asia- western Eurasia (Zelkova), East Asia- North America- western Eurasia (Liquidambar), or restricted to East Asia (Cathaya, Eucommia) or North America (Decodon). A few taxa belong to extinct lineages that have complex biogeographic patterns (Engelhardioideae, Cedrelospermum). The presence of Picrasma (Simaroubaceae) in the lower lignite layers of pollen zone 1 is remarkable, as the botanical affinities with the enigmatic flower Chaneya present in early to middle Miocene deposits of Turkey and Central Europe have recently been shown to be with Picrasma.

We present the results of a pollen analysis performed in la Chaux d'Arlier, an area located in the north-east of France, in the Jura Mountains (Granges-Narboz municipality in the Doubs department, south of the city of Pontarlier). Many burial mounds were discovered in La Chaux d'Arlier. These barrows were built during the Bronze Age and the Iron Age. This area is also known for its wetland density (lakes and peat bogs). The site called « les Emboussoirs » (818 m high) is a polje (a large, flat-floored depression within karst limestone) which began feeding a lake during the last glaciation. According to the sedimentological analysis we are able to trace the evolution of this lake, which became a swamp and then a peat bog. In this sequence we identify four sedimentological units which are lacustrian (U1), unstable transitory (U2), stable transitory (U3) and at last peaty unit (U4).
The age-depth model allows to assign a statistical calibrated dating to sedimentical events (transition between organic rich sediments, altered organic matter, clayed deposits, carbonate deposits). It also allows to date the beginning of anthropogenic indicators curves in the palynological diagram.
Previous palynological studies suggest a first human impact from 3800 cal BC in the nearby peat bog « les Barbouillons » (820 m high), located less than 4 kilometers away from « Les Emboussoirs ». According to this analysis, anthropogenic indicators are continuous since 2700 cal BC, i.e., the Bronze Age. These data support the need for further palynological investigations in order to characterize this settlement.
Three anthropogenic phases are identified in this analysis. The first phase occurs during the Neolithic period between 3265 and 2681 cal BC. Then a more significant anthropogenic phase transformed the vegetation during Bronze Age and Iron Age (1600 cal BC until 148 cal BC). The last period spread between 33 cal BC to the end of sampling 1087 cal AD (88 cm).
The analysis at Les Emboussoirs complements the pollinic signal recorded in Les Barbouillons. Anthropogenic indicators are combined to non-pollen palynomorphs (such as coprophilous fungi spores) recorded in the present study. The study contributes to the description of human activities in Protohistory even though the peaty unit is an unusual poor matter for the palynological preservation. The anthropogenic indicators are also scarce and required an increase of the sampling resolution. This sampling framework is wide (between 5 to 30 centimeters) and doesn't allow an accurate description of the environmental evolution.

Detailed analyses of the Lake Van pollen, Ca / K ratio, and stable oxygen isotope record allow the identification of millennial-scale vegetation and environmental changes in eastern Anatolia throughout the last glacial (∼ 111.5–11.7 ka BP). The climate of the last glacial was cold and dry, indicated by low arboreal pollen (AP) levels. The driest and coldest period corresponds to Marine Isotope Stage (MIS) 2 (∼ 28–14.5 ka BP), which was dominated by highest values of xerophytic steppe vegetation. Our high-resolution multi-proxy record shows rapid expansions and contractions of tree populations that reflect variability in temperature and moisture availability. These rapid vegetation and environmental changes can be related to the stadial-interstadial pattern of Dansgaard–Oeschger (DO) events as recorded in the Greenland ice cores. Periods of reduced moisture availability were characterized by enhanced occurrence of xerophytic species and high terrigenous input from the Lake Van catchment area. Furthermore, the comparison with the marine realm reveals that the complex atmosphere–ocean interaction can be explained by the strength and position of the westerlies, which are responsible for the supply of humidity in eastern Anatolia. Influenced by the diverse topography of the Lake Van catchment, more pronounced DO interstadials (e.g., DO 19, 17–16, 14, 12 and 8) show the strongest expansion of temperate species within the last glacial. However, Heinrich events (HE), characterized by highest concentrations of ice-rafted debris (IRD) in marine sediments, cannot be separated from other DO stadials based on the vegetation composition in eastern Anatolia. In addition , this work is a first attempt to establish a continuous microscopic charcoal record for the last glacial in the Near East. It documents an immediate response to millennial-scale climate and environmental variability and enables us to shed light on the history of fire activity during the last glacial.

This article presents a review of the data collected from the palynological analysis of six sites situated on the southern edge of the Armorican Massif (coastal Vendée, Western France). A multi and interdisciplinary approach, involving branches as diverse as archaeology, history, geography, geomorphology, sedimentology, climatology and the natural sciences, enabled us to gain an understanding of the evolution of vegetation and coastal ecosystems from the end of the Preboreal period to the present, and to see whether this evolution was due to the combined influence of climate and geomorphology of the environment or due to the influence of natural factors, human-induced processes or interaction between these components.
Since the Preboreal, the coastal area has undergone significant geomorphological changes through a succession of marine transgressions and regressions. Coastal valleys filled up rapidly to the Atlantic and the progressive development of dune ridges led to the clogging of lagoons, resulting in the present day tidal marshes. On the first hillsides of the coastal area, and with improvement in climate conditions, a woodland environment rapidly appeared which had distinctive features related to the proximity of the ocean. These data reinforce the research already carried out on the subject and help in an understanding of the evolution of coastal and continental ecosystems. From the end of the Mesolithic period this woodland ecosystem saw clearance activities which were sometimes followed by the cultivation of such plants as cereals or walnut. The discovery of this type of occurrence is not an isolated case in continental Europe. However, the date of these occurrences raises numerous questions about the earliest stages of neolithization, about the diffusion of agricultural knowledge and the factors leading to this diffusion.

Abstract :

The study of gardens, landscapes and ancient cultivated spaces, which was based until around thirty years ago on literary, historical, epigraphic or artistic sources, has since benefited from a more adequate method of analysis : Archaeobotany.

This archaeological discipline brings together but also relies on domains of study whose research supports are plant remains, of a very varied nature, of the micro- or macroscopic order. It tends to show us that life, although ephemeral, never completely disappears. Each category of remains has, in general, its own branch of study : by approaching some of them through various concrete cases of archaeological excavations, we will see that the plant embodies a link between the understanding of the past and apprehension of the future.

Résumé :

L'étude des jardins, des paysages et des espaces cultivés anciens, qui reposait essentiellement, jusqu'à il y a environ une trentaine d'années, sur des sources littéraires, historiques, épigraphiques ou artistiques, bénéficie, depuis lors, d'une méthode d'analyse plus adéquate : l'archéobotanique.

Cette discipline de l'archéologie regroupe mais aussi s'appuie sur des domaines d'études dont les supports de recherche sont des vestiges végétaux, de nature très variée, de l'ordre du micro- ou du macroscopique. Elle tend à nous démontrer que le vivant, s'il est éphémère, ne disparaît jamais totalement. Chaque catégorie de vestiges possède, en général, sa propre branche d'étude : en abordant quelques-unes d'entre elles à travers divers cas concrets de fouilles archéologiques, nous verrons que le végétal incarne un trait d'union entre la compréhension du passé et l'appréhension du futur.

Preventive archaeology and evolution of the vegetation landscape from the Iron Age to the Middle Ages in Gâtinais: highlighting hemp culture and retting activities (Courcelles and Sceaux-en-Gâtinais, Loiret, France)

During the construction of the Highway A19, preventive archaeological excavations were carried out in the Gâtinais and two of them were completed by paleoenvironmental studies. The first site is located in the valley of the Rimarde (Courcelles, Loiret). The samplings were taken from a site near a Neolithic occupation, funeral circles of the Late Bronze Age and a Carolingian necropolis, but the sedimentary sequence only starts during the Iron Age. It is a very open landscape, dominated by agro-pastoral practices which display a major expansion and diversification in the late Roman Empire (cereals, hemp and walnut), and then have their peak in the Early Middle Ages. During Central Middle Ages, rye and flax cultivation appears in the agricultural landscape. The second boring is located between the Maurepas brook (Sceaux-du-Gâtinais, Loiret) and a Gallo-Roman route and remains of buildings. From the beginning of the Iron Age, agricultural and pastoral activities are important. First, the ripisilvae vegetation is maintained and then suffers significant cuts in late Roman Empire. This phenomena is probably in correlation with the strong development of agricultural activities, particularly the cultivation of hemp, and the retting practices. With the distinct decline of these textile activities, the site is invaded by sedge meadow and becomes peaty.

Dans le cadre de la construction de l’autoroute A19, des fouilles archéologiques préventives ont été menées dans le Gâtinais et deux d’entre elles ont été associées à des études paléoenvironnementales. Le premier site se localise dans la vallée de la Rimarde (Courcelles, Loiret). Les prélèvements jouxtent une occupation du Néolithique ancien, des cercles funéraires de l’Âge du Bronze final et une nécropole carolingienne, mais la séquence sédimentaire ne débute qu’au cours de l’Hallstatt. Le paysage est très ouvert, dominé par les pratiques agro-pastorales qui connaissent un important essor et une diversification au Bas Empire (céréales, noyer et chanvre), puis leur apogée au Haut Moyen Âge. Au Moyen Âge Central, la culture du seigle et celle du lin apparaissent dans le paysage agricole. Le second sondage se localise près du ruisseau de Maurepas (Sceaux-du-Gâtinais, Loiret), aux abords d’une voie et de restes de bâtiments de l’époque gallo-romaine. Dès le début de l’Âge du Fer, la céréali- culture et les activités pastorales sont très présentes. La végétation de ripisylve, d’abord entretenue, subit ensuite des coupes importantes au Bas Empire, probablement en relation avec le fort développement des activités agricoles, notamment celui de la culture du chanvre, et des pratiques de rouissage. Avec le net recul de ces activités chanvrières, le site est envahi par la cariçaie et devient tourbeux.

Before the closing of its lagoons and the progradation of the Hebros delta, Ainos took advantage of an almost insulate position, which made it one of the main hubs between the Greek Aegean and the Thracian hinterland. Annual Turkish archaeological excavations (since 1973) and international geoarchaeological research (since 2011-2012) have revealed several components of the polis’ territory (necropoleis, roads, anchoring sites, fortifications) and offered information about the ecological impact of the Greek, Roman, Byzantine and Ottoman occupation on the natural environment. This article is a short critical synthesis of these discoveries, which can serve as a basis for the reconstruction of Ainos’ environmental history.

the ‘taxodiaceous’ Cupressaceae typically has a papilla in the leptoma area and is common in Cenozoic strata because some
of its genera were key elements in lignite forming swamp forests. Dispersed fossil pollen of this group are often assigned to
particular genera and, based on the modern ecologies of these taxa, to particular palaeoenvironments. In this study, we
investigated pollen of all nine genera of the former Taxodiaceae using light and scanning electron microscopy to evaluate
whether pollen morphology can be used to discriminate modern genera of this paraphyletic group. We found few genus- or
subfamily-diagnostic characters among members of taxodiaceous Cupressaceae. Features such as orbiculae and pollen and
leptoma size cannot be used to discriminate subfamilies. However, three basal subfamilies share short papillae, whereas in
two more derived clades (Sequoioideae and Taxodioideae) papillae are markedly longer. In the generally non-papillate core
Cupressaceae, the leptoma (aperture) area may or may not possess a distinct circular thinning as also found in the basal
grade of taxodiaceous Cupressaceae. Our results show that it is difficult if not impossible to distinguish genera of the
ecologically distinct Taxodioideae and Sequoioideae based on pollen morphology. In view of a much wider ecological
amplitude of many taxodiaceous Cupressaceae during large parts of the Cenozoic, we conclude that it is not recommendable
to infer particular palaeoenvironments on the basis of dispersed taxodiaceous pollen grains alone.

Honey is a natural product that acts directly on our biological systems in a significant number of ways. Amongst the many health benefits of honey are its antioxidant, antifungal, anticancer and bacteriostatic properties to its free fat and cholesterol values.Today, the density and availability of these plant species which honey bees forage for nectar are threatened by the vicious impart of climate change, environmental degradation and over exploitation by man for his livelihood options. Systematic identification and documentation of these species is the basic prerequisite for their conservation and sustainability. The major aim of this work was to evaluate palynologically after acetolysis the pollen spectrum of five honey samples from three zones in Southern Nigeria. The results showed diversity of fifty-sixty (56) honey plants belonging to twenty one (21) plant families distributed within 53 genera comprising of 19 dicots and 2 monots. Three predominant families were frequently encountered, these were Fabaceae, Euphorbiaceae and Anacardiaceae contributing a total of 1672.74 plants pollen with 983.45 (58.79%), 372.9 (22.29%) and 316.3 (18.9%), respectively. Fabaceae contributed the highest honey plant of (9) species Senna hirsuta L, Danialla oliveri (Rolfe) Hutch & Dalz. Brachystegia eurycoma Harms, Senna occidentale L. Link, Isoberlinia dokas Craib & Stapf, Erythrina senegalensis D.C., Albizia zygia (DC.) Macbr, Tephrosia bracteolate Guill. & Perr, Tephrosia purpurea L., Parkia biglobosa (Jacq) R. ex Don-H.C., Entada abyssinica Steud. ex A. Rich., Crotolaria retusa L. and Dialium guineense Willd. Predominant honey plants were Anacardium occidentale L, Ageratum conyzoides L, D.oliveri, Alchornea cordifolia Muell, Arg, Trichilia spp and Elaeis guineensis Jacq. with 31.14, 32.48, 39.9, 58.74, 35.26 and 60.92 %, respectively. The result equally reflected the habit and conservation status of these predominant honey plants. Apart from A. occidentalis and E. guineensis which are cultivated, others are found in the wild and are vulnerable to climate variability and change (threatened). Poor pollen spectrum recorded in some samples could be a reflection of loss of bioresources attributed to high level of anthropogenic activities. It is therefore, recommended that policy makers and indeed beekeepers in these zones as a matter of urgency should embark on extensive propagation, afforestation, and conservation of these predominant honey plants within their apiaries to improve food security, income generation for farmer’s and as carbon repossession in the ecosystem.

proposed three similarly constructed fossil generic spore names with the first word base, Laevigat-, attached to the uniform ending-sporites giving the three generic names: Laevigata-sporites, Laevigati-sporites and Laevigato-sporites. The names were proposed as part of Ibrahim's original morphographic classification of fossil spores, in which the stem base (first element) of the generic name with different and varying endings (e.g.,-a- ,-es- ,-i-, or-o-) is attached to the uniform ending-sporites; the particular ending of the stem base, coming in the middle of the name, being an important key to the taxonomic position of the spore genus in his suprageneric artificial, morphographical groupings (Aletes [-a-], Monoletes [-o-] and Triletes [-i-and-es-], vide Ibrahim, l.c.: 15–16). As a result, several sets of nearly similar generic names were produced (The International Fossil Plant Names Index, 2014–onwards [http:// fossilplants.info/about]):

A newly discovered locality of an hitherto unknown age, but now estimated to the Late Ordovician, in south-eastern Morocco has yielded numerous specimens of problematic soft-bodied metazoans preserved in coarse sandstones. The excellent preservation of the recovered specimens permits an improved understanding of both the palaeobiology of these Ordovician metazoans and the taphonomic processes associated with them. This style of soft tissue preservation is closely comparable to that of the late Neoproterozoic problematic Ediacaran organisms, and is virtually absent in the Phanerozoic. Palynological analysis (chitinozoans and acritarchs) of shaly intercalations in an ophiuroid-bearing sandstone slab facilitates accurate identification of the site as belonging to the Upper Ktaoua Formation and thus a relative dating of the associated fossils. The chitinozoan assemblage is relatively well preserved, moderately diverse and closely comparable to the previously described chitinozoan fauna from the Upper Ktaoua Formation (Rawtheyan, late middle Ashgill age). Acritarchs are abundant but mostly ill-preserved; nonetheless they clearly indicate an undifferentiated Ashgill age, consistent with the chitinozoan chronostratigraphic result. These datings prove that the newly discovered Moroccan metazoan assemblage contains one of the oldest
known paropsonemids, and possibly some of the youngest protolyelloids and aglaspidids. The new finds also show that Ediacara-like coarse-clastic preservation did not completely vanish with the onset of the Phanerozoic.

Au tout début de la période romaine, un taux d’arbres inhabituellement élevé a été mis en
évidence par la palynologie sur le site de la Source des Roches à Chamalières (Puy-de-Dôme),
gisement qui a livré plus de 3500 ex-voto en bois au début des années 70. Durant le second
âge du Fer et l’époque romaine, un tel niveau de boisement n’est observé nulle part ailleurs,
ni en plaine de Limagne, ni sur le plateau des Dômes. L’hypothèse d’un sanctuaire de plein
air, soutenue par Anne-Marie Romeuf qui a dirigé la fouille, se trouve ainsi confortée par
l’analyse pollinique, qui permet d’envisager la possibilité de la présence d’un « bois sacré »
composé principalement de chênes. La combinaison des données archéobotaniques issues de
la palynologie et de la carpologie contribue à renforcer la compréhension du site d’un point
de vue paysager et nous renseigne également sur les types d’offrandes végétales associées au
dépôt des ex-voto.

Abstract :

The study of gardens, landscapes and ancient cultivated spaces, which was based until around thirty years ago on literary, historical, epigraphic or artistic sources, has since benefited from a more adequate method of analysis : Archaeobotany.

This archaeological discipline brings together but also relies on domains of study whose research supports are plant remains, of a very varied nature, of the micro- or macroscopic order. It tends to show us that life, although ephemeral, never completely disappears. Each category of remains has, in general, its own branch of study : by approaching some of them through various concrete cases of archaeological excavations, we will see that the plant embodies a link between the understanding of the past and apprehension of the future.

Résumé :

L'étude des jardins, des paysages et des espaces cultivés anciens, qui reposait essentiellement, jusqu'à il y a environ une trentaine d'années, sur des sources littéraires, historiques, épigraphiques ou artistiques, bénéficie, depuis lors, d'une méthode d'analyse plus adéquate : l'archéobotanique.

Cette discipline de l'archéologie regroupe mais aussi s'appuie sur des domaines d'études dont les supports de recherche sont des vestiges végétaux, de nature très variée, de l'ordre du micro- ou du macroscopique. Elle tend à nous démontrer que le vivant, s'il est éphémère, ne disparaît jamais totalement. Chaque catégorie de vestiges possède, en général, sa propre branche d'étude : en abordant quelques-unes d'entre elles à travers divers cas concrets de fouilles archéologiques, nous verrons que le végétal incarne un trait d'union entre la compréhension du passé et l'appréhension du futur.

International audienceThe research carried out since 2010 on the granitic plateaus of the Haute-Combraille, in the west of the department of Puy-de-Dôme, as part of the MINEDOR program (Archaeological and palaeo-environmental characterization of Arverni’s gold mines in Haute- Combraille) of the Clermont-Ferrand MSH, have highlighted the key role of mining in the process of turfigenesis at the origin of peatland formation. One of the main objectives of this interdisciplinary research program was to characterize the ancient gold mining phases through their environmental impact, by coupling palynological and isotopic analyzes of samples taken in peat bogs. However, it appears that all peatlands identified and analyzed are closely connected to gold mines, whether they are in the immediate vicinity or even inside these mines, the oldest of which date back to the Second Iron Age. Indeed, mining works have the effect of disrupting local drainage networks, either voluntarily for the needs of the extraction (tanks, washery), or indirectly during their abandonment (accumulation of water in the cavities, clogging ditches due to the erosion of the dumps). While highlighting this phenomenon has important methodological (and even epistemological) consequences for palaeoenvironmental analyzes, it also opens up new perspectives by showing the fundamentally anthropogenic nature of many wetlands. From a landscape history point of view, the close link between mines and peatlands is a result whose scope will have to be measured, as peatlands, which are considered as “natural environments” to be preserved for their natural resources and their biodiversity, appear here as the consequence of highly polluting activities. However, they could play a key role in trapping paleo-pollutions, thus avoiding their diffusion into the environment.Les recherches conduites depuis 2010 sur les plateaux granitiques de la Haute-Combraille, dans l’ouest du département du Puy-de-Dôme, dans le cadre du programme MINEDOR (Caractérisation archéologique et paléo-environnementale des mines d’or arvernes de Haute-Combraille) de la MSH de Clermont-Ferrand, ont mis en évidence le rôle déterminant des exploitations minières dans le processus de turfigenèse à l’origine de la formation des tourbières. L’un des objectifs prioritaires de ce programme de recherche interdisciplinaire était de caractériser les phases d’exploitation aurifère anciennes à travers leur impact environnemental, en couplant analyses palynologiques et isotopiques d’échantillons prélevés dans des tourbières. Or il apparaît que toutes les tourbières identifiées et analysées sont étroitement connectées à des aurières, qu’elles se situent à proximité immédiate ou à l’intérieur même de ces mines dont les plus anciennes datent du Second Âge du Fer. En effet, les travaux miniers ont pour effet de désorganiser les réseaux de drainage locaux, soit volontairement pour les besoins de l’exploitation (réservoirs, laveries), soit indirectement lors de leur abandon (accumulation d’eau dans les cavités, colmatage des fossés du fait de l’érosion des haldes). Si la mise en évidence de ce phénomène a d’importantes conséquences méthodologiques (et même épistémologiques) pour les analyses paléoenvironnementales, elle ouvre aussi de nouvelles perspectives en montrant le caractère fondamentalement anthropique de bon nombre de zones humides. Du point de vue de l’histoire des paysages, le lien étroit entre mines et tourbières est un résultat dont il faudra mesurer la portée, car les tourbières, qui sont considérées comme des « milieux naturels » par excellence, à préserver pour leur ressource en eau et leur biodiversité , apparaissent ici comme la conséquence d’aménagements liés à des activités en l’occurrence très polluantes. Toutefois, elles ont pu jouer un rôle essentiel dans le piégeage des paléo-pollutions, évitant ainsi leur diffusion dans l’environnement

Parmi les derniers developpements en matiere de palynologie, un nombre croissant de travaux s’interesse notamment a la reconstitution quantitative du couvert vegetal. En effet, la relation non-lineaire observee entre les comptages polliniques et la vegetation, principalement liee a des differences interspecifiques de production pollinique et de dispersion du pollen, peut etre corrigee via l’utilisation de modeles mathematiques comme le Landscape Reconstruction Algorithm, avec ses deux sous-modeles REVEALS et LOVE .L’application du modele REVEALS aux donnees holocenes du Bassin parisien a permis d’obtenir une estimation des proportions relatives des principaux taxons presents dans le paysage, au niveau regional. Ces resultats modifient significativement la hierarchie des differentes essences floristiques. Par exemple, la part accentuee des taxons herbaces dans les quantifications conduit a une importante reevaluation de l’etendue des milieux ouverts durant toute la periode postglaciaire. De meme, on percoit plus fortement l’impact sur le paysage des pratiques agro-pastorales au travers de proportions accrues des taxons marqueurs d’anthropisation.

This paper reviews the palaeobiogeography of Taxus baccata (yew) and the human social customs and traditions relating to this tree in southwest Europe. Pollen and archaeobotanical (charcoal, seeds and manufactured tools) evidence supplemented by some data from ethnographical sources have been considered in an integrated approach focused on the Holocene. The geographical scope covers northern Spain, including both sides of the Pyrenees to southeast France, northeast Spain and the Balearic islands. Although the first archaeobotanical occurrences of yew have been recorded at 12–8 cal. kyr bp, the highest values have been found between 7,000 and 2,000 cal. bp as reflected in its maximum pollen curves in the study area. According to the pollen records this taxon had a first significant presence within the mixed oak woods and then it gradually disappeared (ca. 3,000 bp) from middle altitudes. This might be due to a combination of changing climatic conditions responsible for the major Holocene vegetation changes and increasing human pressure. A wide diversity of human uses is observed in the record of yew macroremains from archaeological sites. The presence of charcoal, potentially consumed fruits, manufactured tools and other archaeobotanical evidence of yew associated with livestock activities lead us to propose a set of past uses that may have contributed to its clear decrease in the late Holocene. Despite this intensive exploitation it is also rather common to find old specimens of planted yew throughout the study area, witnessing its endurance in the memories of people wherever it has remained.

Because of their small size and vast abundance in various types of sedimentary rocks, microfossils have found a multitude of applications in geology, especially regarding biostratigraphy, correlations and paleoenvironmental analysis. Organic-walled microfossils such as pollen, spores, and various organic debris derived from terrestrial plants, are especially useful when studying terrestrial deposits. This chapter presents the many different groups of organic-walled microfossils, collectively called palynomorphs, and the different methods palynologists use to study and extract them from sediments and rocks. We present a biostratigraphic application, the use of the pollen and spore record across the Cretaceous–Paleogene boundary, which has proven to be one of the most precise and reliable means for pinpointing this major transition within terrestrial deposits.