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This paper presents a long-term synthetic overview of the socio-ecological dynamics responsible for the shaping of present-day rural landscapes in the Spanish Central System. Available historical and palaeoenvironmental records have been compiled and cross-referenced to characterise key transformations unfolding in this mountainous macro-region during the medieval time span. A sharp deforestation of upland pines and midland oaks was due to extensive Late Antique strategies. Pre-tenth-century trajectories are diverse and exhibit the recovery of high-mountain pine forests and highly localised agro-pastoral impact on selective mid-altitude niches. The eleventh-century early repopulation policy implied migrations, increased momentum of rural village foundation and extension of colonised agrarian landscapes in the tablelands of the Extremadurii. The pace and intensity of these phenomena depended on ecological and historical circumstances, leading to subsequently different realities. By the mid-thirteenth century the definitive pacification and the rising demographic trend facilitated the later permanent occupation and the ensuing integral and sustainable exploitation of the highlands – and especially the Transierra – within the feudal system. High-altitude landscapes exhibit intensive forest clearances due to transterminant livestock movements and the benefit of seasonal resources, whereas low-altitude settings specialised in arboriculture and diversified crops to supply urban markets. [ABSTRACT FROM AUTHOR]

Fire has been one of the main causes of disturbance of vegetation over time, and since the Neolithic has become an irreplaceable tool for the opening of forest spaces and maintenance of pastures. Previous studies showed that the intensity and effects of wildfires are related to the biomass and controlled by climate factors. However, in regions such as Cantabria, where agriculture and livestock have spread throughout the territory since prehistory, fires should also be closely related to human land uses. The aim of this paper was to investigate the history of fires and vegetation since the Neolithic in the Cantabrian Mountains, using sedimentary charcoal and pollen data to study the role of human activities in the processes that have shaped ecosystems throughout the Holocene. The asynchrony and quantitative differences in the results obtained at different sites indicate significant variations in fire patterns at regional scale since the Neolithic, although the type and size of each basin also had a strong influence on charcoal accumulation. Maximum values for charcoal accumulation rate at La Molina were observed between the Neolithic and the Bronze Age but occurred after about 3500 cal years BP at El Cueto de la Avellanosa. At El Sertal, low charcoal accumulation rate values were observed, probably because the sequence begins in a space that already had been cleared; the maximum values occurred during the most recent millennium. These data provide evidence that fire has been a key factor in forest retreat and in maintaining open landscapes since the Neolithic. [ABSTRACT FROM AUTHOR]

New palynological results from the Gafo Formation (southern sector of the Pulo do Lobo Domain, South Portuguese Zone) are integrated with recently studied sections and drillholes from the Portuguese and Spanish sectors. A total of 44 samples were studied, 27 of which were positive for palynomorph taxonomy. This research revealed well preserved palynological assemblages, including 73 spore species allocated to 28 genera, four acritarch genera, three prasinophyte algae genera plus common chitinozoan remains. Some additional forms were retained under open nomenclature. From this, the first complete age determination for the Gafo Formation in Portugal and Spain was achieved, indicating a middle Famennian (Grandispora gracilis–Grandispora famenensis, GF Biozone) to a late Famennian (Grandispora echinata, VH Biozone) age. A greywacke sample from the same Gafo Formation was dated by U–Pb zircon geochronology and a maximum depositional age of 369 ± 2.5 Ma was obtained. A correlation between these palynological and U–Pb zircon data and the palynoflora assemblages of previous authors was made, as well as with the ages of felsic volcanic rocks found intercalated in the Gafo Formation, confirming the complex stratigraphy of Pulo do Lobo Domain. The results are consistent with stratigraphic mapping and structural interpretations, allowing a middle–late Famennian age (GF and VH Biozone) to be assigned to the Gafo Formation sedimentary rocks. This work has also contributed to a reinterpretation of Gafo Formation depositional facies correlatives (e.g. the Santa Barbara Group in Spain) as being the same lithological unit. [ABSTRACT FROM AUTHOR]

The present paper reports a complete palynological study of the Upper Turolian sediments outcropping at the Venta del Moro site (eastern Iberian Peninsula). The pollen assemblages observed mainly reflect the local and regional vegetation, which must have formed part of a wetland ecosystem within a general setting of open steppe, as indicated by the great abundance and diversity of herbaceous pollen. This reflects the persistence of open vegetation in the Iberian Peninsula after the Middle Miocene when it became extensive. We here report the most recent record of Disanthus for the Iberian Peninsula. This shrub played an important role in an unusual, edaphically-mediated vegetation linked to lacustrine–palustrine or riparian shore conditions. A shift in the water level led to a flooding episode, extending wetland and causing a drastic reduction in Disanthus and Amaranthaceae. The results of quantitative (multivariate and coexistence) and semi-quantitative (integrated plant record) analyses of the pollen dataset support these interpretations of the palaeovegetation and provide insight into the regional palaeoclimate. Stable climatic conditions would appear to have reigned before the onset of the Messinian salinity crisis. The palynoflora of Venta del Moro is compared with counterparts in other areas of the Mediterranean Basin. [ABSTRACT FROM AUTHOR]

Abstract: According to pollen analysis and the 18O-isotope curve, the first part of the Late Pleistocene (ca 128–30 ka) is mainly characterized by a dynamic that alternates cold phases (Heinrich Events) and temperate phases (interstadials). These rapid fluctuations provide the context for the Neanderthal occupations in the northeastern part of the Iberian Peninsula. In this paper we present the chronological, environmental and climatic data obtained by analyzing the pollen, the charcoal, the small vertebrates (amphibians, squamates and small mammals) and the large-mammal dental wear at the Neanderthal site of Teixoneres cave, Northeastern Iberia. Levels II and III from this cavity have provided Mousterian industries and other evidence of Neanderthal occupations, such as cut-marks in large-mammal bones. A multiproxy study such as this constitutes a new approach to the chronological, environmental and climatic context in which Neanderthal populations lived in southwestern Europe (Iberian Peninsula). The results allow us to establish a relative chronology for these two levels of between ca 30–90 ka and show that they are associated with different environmental and climatic conditions: temperate and humid for Level III and cold and dry for Level II. This demonstrates that the Neanderthals were well adapted to the territory that they occupied, irrespective of the climatic conditions. [Copyright &y& Elsevier]

Abstract: Plant fossils are rarely preserved within the Upper Permian of western Europe as the majority of continental deposits consists of siliciclastic redbeds. Because organic matter such as plant debris and palynomorphs is destroyed by oxidizing conditions, these red sedimentary facies were often considered as “devoid of life”. This paper presents new palaeobotanical data from the Upper Permian strata of Minorca (Balearic Islands, Spain). In addition, a rich and diverse “Thuringian” palynoflora was recovered from the Permian sediments, and several megafloral taxa are recorded. Additionally, a detailed sedimentological analysis of the studied section is provided. The Permian succession shows a general evolution from a ponded floodplain environment to sand-sheet rivers flowing across a semi-arid alluvial plain. Additionally, new palaeobotanical elements, added to the study of palaeosols, allow reconstruction of Late Permian plant growth within the terrestrial environment, as well as a palaeoenvironment reconstruction of the preserved sedimentary interval. At the transition between ponds and alluvial plain deposits, root systems surprisingly similar to those known in extant mangroves are described for the first time within Permian deposits. As there are no other palaeobotanical remains preserved in association, the type of plant that inhabited this environment remains conjectural. [Copyright &y& Elsevier]

Abstract: In this paper we present a review of the available pollen analyses in the north-western Iberian Range with the aim of studying Fagus glacial refugia and Holocene expansion. The work collects the available pollen analyses in the area (24 sites and 58 14C dates). Based on the available palynological data, we try to reconstruct the changes that occurred in the distribution of Fagus sylvatica in the north-western Iberian Range during the late Pleistocene and the Holocene, its spread patterns and the possible causes for such changes. Results from pollen analyses allow establishing at the Middle Holocene the beginnings of Fagus expansion mostly in relation to anthropic activities. Also, the pollen data demonstrate the existence of Fagus glacial refuge during the Late Pleistocene and the Early Holocene. Therefore, we hypothesize that present-day beech forests, in the area under study, are the direct result of the relic populations that survived the last glaciations and that have been favoured by both environmental conditions and human activities. [Copyright &y& Elsevier]

Abstract: This paper uses a palynological sequence to examine the Holocene (8390–160calyrBP) environmental history of the Sierra de Baza (Granada, southeastern Spain) with the goal of establishing the mechanisms exerting control over vegetation change. During the period ca 8390–6320calyrBP, Pinus dominated the pollen spectra, indicating a forested landscape over the high-elevation areas of the Sierra. From ca 6320–3800calyrBP, an expansion of deciduous oaks and other broad-leaf trees took place. After an optimum around 5800–5600calyrBP, mesophytes decreased in the 3800–2560calyrBP interval while a fire-prone scrub became established. The main loss of forest accompanied the spread of thorny matorral after ca 2560calyrBP. Overall, this mountain region has shown itself to be sensitive to a range of influences, among which a continental climate that has become increasingly arid over the last 5000 years, the scarcity of soils suitable for cultivation, a geology that includes sources of copper and other metals and, especially, the incidence of grazing as well as the repeated appearance of fires during the last 4000 years, are highlighted. The history of the vegetation of the Sierra de Baza seems clearly influenced by changes in local economy. Here we discuss how ecological transitions have interacted with cultural changes, with emphasis on the locally highly populated Chalcolithic (5700–4400calyrBP) and Argaric (4400–3550calyrBP) periods, as well as the Iberian period (3200–2220calyrBP). The sierra was abandoned during the Iberian Period which was, paradoxically, when the highest human impact on mountain vegetation is noticeable. [Copyright &y& Elsevier]

Abstract: This paper presents a mid- to late-Holocene vegetation sequence of a Juniperus thurifera-dominated area in the eastern, continental plateaux of the Segura Mountains of southeastern Spain. A mid-Holocene maximum of mesic tress is recorded in the pollen diagram between c. 6640 and 4790 cal years BP with the vegetation dominated by deciduous oaks. A dramatic decline in deciduous oaks occurred from approximately 4700 cal years BP to be replaced initially by evergreen oak, and then junipers and other xerophytes from c. 4500 cal years BP. This trend of xericness in the vegetation is coherent with regional and extra-regional palaeoclimatic records for increased mid-Holocene aridity. Significant anthropogenic modification of the vegetation occurred in this region from c. 1350 cal years BP represented by a large reduction in all tree taxa (except Juniperus) and increases of thorny scrub and nitrophilous assemblages. Increased fire incidence, pastoralism, and arboriculture were associated with this anthropogenic activity. We conclude that present-day J. thurifera-dominated communities in this region have become established through a combination of two predominant processes; increased aridification from c.4500 cal years BP and anthropogenic activity from c. 1200 cal years BP. [Copyright &y& Elsevier]

Integration of a diverse set of data from pollen, wood, macrofossils and dendrochronological studies from the Sierra de Ayllón, a mountainous region in central Spain, enables one of the most complete palaeoecological vegetation reconstructions for almost the whole Holocene on the Iberian Peninsula. Previously, the absence of pollen data for the early Holocene in the eastern part of the Sistema Central mountains had been a gap in the information needed for correctly reconstructing palaeoenvironmental change there. Our pollen study on the Valdojos site finally allows this issue to be resolved. This analysis highlights the crucial role played by pine woodlands throughout the first half of the Holocene in this region. The importance of the pine woods in the region enables us to show the clear difference in vegetation between the western and eastern parts of the Sistema Central mountains for the early to mid Holocene. Moreover, the Fagus pollen found at Valdojos, dating to ca. 7,000–6,600 cal years bp, is the oldest beech record for the central and eastern part of this chain of mountains during the Holocene. This supports the hypothesis of the existence of beech refuges in the Sistema Central for this time span. Furthermore, we used the tree-ring series from the Pinus cf. sylvestris subfossil wood from the Sandria site to extend the previous data from the Sierra de Ayllón to almost the entire Holocene. This tree-ring record is the most complete data set from the Iberian Peninsula and southern Europe and it also provides data on some aspects of the palaeoenvironment. [ABSTRACT FROM AUTHOR]

This paper presents a palynological study of the archeological layers from the Neanderthal site Abrigo 3 del Complejo del Humo, in southern Spain (Málaga), with the aim of reconstructing the environmental conditions in the vicinity of this hominin site. The Upper Pleistocene vegetation and its variability are described, revealing a high diversity of thermophilous plant taxa throughout the cold dry phases, together with a long-term persistence of woody taxa, including Mediterranean, mesophytes, xerothermics and conifers. With the pollen records of Maytenus senegalensis as an outstanding finding, this study demonstrates the co-existence of temperate, Mediterranean and Ibero-Maghrebian angiosperms on the southern coastal plains of the Iberian Pleistocene where Neanderthals survived for a long time. It is therefore clear that Neanderthals and early Upper Paleolithic modern humans lived in a litoral refugium, which was a propitious environment for maintaining a high biodiversity, including potentially edible plant species. Besides, this coastal refugium offers broad possibilities for hunting, and interpopulational relationships through coastal platforms. • A palynological study of the archeological layers from the Neanderthal site of Abrigo 3 del Complejo del Humo. • A high diversity of thermophilous plant taxa throughout the cold dry phases. • The co-existence of temperate, Mediterranean and Ibero-Maghrebian angiosperms in the southern of the Iberian Pleistocene. • Neanderthals and early Upper Paleolithic people lived in a litoral refugium. [ABSTRACT FROM AUTHOR]

This paper presents pollen analyses and radiocarbon dating on Crocuta coprolites from Las Ventanas (LV) and Carihuela (Car) Caves in southern Spain (Granada), with the aim of reconstructing the environmental conditions of these hominin sites. The LV coprolites are radiocarbon dated from c. 37,890 to 6980 cal yr BP, and the Car coprolites from c. 31,063 to 7861 cal yr BP. Overall, the palaeoecological scenario inferred from both coprolite series display similar patterns, with Pinus , Poaceae, and Artemisia as dominant during the full Pleistocene, and an important contribution of Quercus in the most recently dated coprolite samples. While the palynology is consistent with results of former investigations on the past environments in the region as obtained from other deposits (peat bogs, cave infills), the Late Glacial and Holocene chronology of several coprolites in both sites is in conflict with the generally accepted timing of extinction of Crocuta in western Europe. A discussion on the taphonomical processes and potential sources of carbon contamination of the radiocarbon samples is provided. The correlation between pollen from coprolites and from sedimentary records, and the paucity of the fossil bone record suggests nevertheless, that a late survival of Crocuta in southern Spain should not be categorically discarded. • New pollen analyses and radiocarbon dating on Crocuta coprolites from Las Ventanas (LV) and Carihuela (Car) Caves. • The palaeoecological scenario inferred from both coprolite series display similar patterns. • Timing of extinction of Crocuta in western Europe. • A late survival of Crocuta in southern Spain should not be categorically discarded. [ABSTRACT FROM AUTHOR]

Ole e 1 protein is involved in olive fertilization mechanisms controlling pollen tube development. Similarly to the process by which pollen grains hydrated and form a pollen tube upon arrival at the female gametophyte, when pollen grains fall on the nasal mucosa the expression of Ole e 1 protein induce allergic reaction in sensitive individuals. The research was conducted in Ourense (North-western Spain), during the 2009–2018 period. Ole e 1 protein was collected using a Cyclone Sampler and processed with the ELISA methodology. Airborne Olea pollen were monitored using a Hirst type volumetric sampler. Allergy risk episodes identified by pollen concentrations were detected in five of the 10 studied years, all with moderate risk. Actual risk episodes of allergy increased when the combination of pollen and Ole e 1 concentrations were considered. Moderate risk episodes were detected during 9 years and high-risk episodes during 3 years. In addition, some years of low annual pollen concentrations recorded high total amounts of Ole e 1. During the years with lower pollen production, the tree increases the synthesis of Ole e 1 to ensure proper pollen tube elongation in order to complete a successful fertilization. This fact could justify higher sensitization rates in years in which a lower pollen production is expected. The present method contributes to the determination of the real exposure to Ole e 1 allergen evaluating the role of this protein as an aeroallergen for sensitized population. The allergen content in the atmosphere should be considered to enhance the prevention of pollinosis clinical symptomatology and the reduction of medicine consumption. [ABSTRACT FROM AUTHOR]

A new nothospecies Ranunculus ×prieti is described following morphological and molecular characterization. Hypervariable Amplified Fragment Length Polymorphism (AFLP) markers, flow cytometry (FCM) analysis and pollen viability were conducted. The profiles of hybrid samples were compared to their presumed parental taxa R. amplexicaulis and R. gramineus. Morphological study revealed that all hybrid individuals were morphologically intermediate between their parents, showing ovate-lanceolate basal leaves and amplexicaul cauline leaves as in R. amplexicaulis and yellow corollas as in R. gramineus. Principal coordinates analysis of the AFLP data set showed that hybrids are closer to R. gramineus than to R. amplexicaulis, whereas the results obtained by flow cytometry indicate otherwise. Pollen fertility estimation of R. ×prieti ranged from 68.83 to 95.81%, showing that hybrid samples are well established and fertile. [ABSTRACT FROM AUTHOR]

The biostratigraphical ranges, geographical distribution and taxonomy of 45 dinoflagellate cyst species are described based on the analysis of 99 samples from the Upper Cenomanian–Lower Turonian outcrop sections of Puentedey, Fuentetoba, Condemios and Tamajón in northern Spain. A specific rank for Coronifera hebospina (formerly Coronifera oceanica subsp. hebospina) and the new combination Exochosphaeridium majus are proposed. The generic assignment of Implestosphaeridium? clavulum and Implestosphaeridium? polytrichum are questioned. Early Turonian range tops for Coronifera albertii, Cyclonephelium vannophorum and Palaeohystrichophora palaeoinfusa are confirmed. [ABSTRACT FROM PUBLISHER]

Macroscopic charcoal, pollen and non-pollen palynomorphs were isolated from a colluvial soil located on a small hill in Campo Lameiro (NW Spain) in order to elucidate the vegetation history of the area and its relation to fire and human activities. The presence of macroscopic charcoal throughout the 2.10 m thick soil (42 samples) is evidence of frequent fires during the last c. 6300 years. The charcoal record was dominated by Quercus (probably Q. robur), Ericaceae (probably Arbutus unedo and Erica arborea) and Fabaceae (mainly Genista type). Abrupt changes in the charcoal assemblage are less explicit in the pollen sequence, probably as a result of pollen inflow from the downhill surroundings of the study site. Combined results indicated that the original oak woodland was gradually replaced by pyrophytic shrubs (Ericaceae and Fabaceae) as a result of fire recurrence. Non-pollen palynomorphs strongly suggested that vegetation was deliberately ignited by past human societies to facilitate grazing. No evidence of local agricultural practices was found. Episodes of accelerated shrubland expansion occurred c. 6000-5500 cal. BP, c. 4000-3500 cal. BP and c. 1700 cal. BP, the latter of which caused the definitive settlement of shrublands dominated by Ericaceae and Fabaceae which are nowadays widespread in NW Iberia. [ABSTRACT FROM AUTHOR]

Abstract  Estimations based upon geostatistics and mapping have enabled the construction of a spatial model to predict the presence of biological particles in a particular region. This methodological proposal has been tested in a case study, at a regional scale, of airborne Olea pollen, using the data acquired from␣various sampling stations that are designed for the aerobiological monitoring of pollen levels. These sampling stations have been set up in cities throughout the region of Andalusia (southern Spain) at sites with very different characteristics in terms of biogeography, bioclimate, topography and vegetation. Pollen counts were made daily at all sites during 2003 using a volumetric spore-trap. Data were comparatively analysed in classical diagrams and by means of spatial-temporal maps. Space-time models were constructed using three coordinates, x, y (the UTM coordinates of each sampling station) and z, (the aerobiological data compiled for a specific period). The aerobiological data were interpolated by applying the traditional geostatistical method of Kriging. The introduction of the variable “space” into the model allowed us to predict pollen levels in different areas throughout the region. The interpolation method was used to make weekly estimations of Olea pollen values in areas where there was no aerobiological sampling station. In addition, the maps generated present a two-dimensional vision of the study area, showing that bioclimatic diversity of this region promotes a step-wise flowering of Olea. [ABSTRACT FROM AUTHOR]

A preliminary study to compare Poaceae pollen data and to determine possible differences in pollen productivity and/or seasonality was performed at six locations in Catalonia (Spain): Barcelona, Bellaterra, Girona, Lleida, Manresa and Tarragona over a 6-year period (1996-2001). In the study area, Poaceae pollen grains are an important cause of respiratory allergies. Being present in the atmosphere all year round, the grass pollen concentrations are especially significant between May and August. The absolute peak occurs in June, except in Lleida where the peak comes earlier, possibly due to the early flowering of particular steppe species. Even if there are differences between different years, Girona and Lleida (inland locations) usually present the highest annual grass pollen index with, on average, 2177 pollen grains per year. Barcelona and Tarragona (the coastal sites) show the lowest levels, with around 1140 grass pollen grains per year. The respective local climates are very different, and pollen grains may originate in different grass species. A decreasing trend in the Poaceae annual pollen index was found over the period of the present study. [ABSTRACT FROM AUTHOR]

Temperature is one of the main factors affecting the start of flowering in tree species that flower at the beginning of spring. Knowledge of the chilling and heat needs required by plants to overcome the period of dormancy enables us to determine the onset of pollination, which is of great importance to allergy sufferers. This study attempted to obtain behaviour models with a view to determining both the onset of the olive pollen season and daily pollen concentrations during the pollination period in Vigo. Monitoring was carried out using a Lanzoni VPPS 2000 pollen trap, from 1995 to 2002 inclusive. Olea pollen is mainly detected during the spring, principally in May. Given the geographical location, the very limited presence of this tree in the study area and the low Olea pollen concentrations detected in northern Spain as a whole, the values recorded here in the atmosphere of Vigo are particularly striking. A strong correlation was observed between total quantity olive pollen collected over the season and rainfall recorded during the second fortnight in February. According to the proposed model, an average of 680 Chilling Hours (CH) are necessary to overcome the chill period and break the state of bud dormancy, and 481 Growth Degree Days (GDD) °C are needed to induce flowering. Models for predicting daily mean pollen concentrations combine temperature and the previous days' pollen concentrations as predictor variables to provide a high level of prediction. [ABSTRACT FROM AUTHOR]

Since the beginning of aeropalynology, aerobiologists have tried to develop models able to predict the pollen load of the atmosphere to help physicians and patients suffering pollen allergies to improve the efficiency of pollen allergies prophylaxis. Some models have been developed by aerobiological services and are used for real time predictions, now provided online. They are statistical models and require the pollen load of the previous days as input, as well as statistics on the pollen load of the previous years, daily meteorological data and geographic information on the pollen sources. Here we propose to use process-based phenological models to predict the time course of the pollen load of the atmosphere using solely daily mean temperatures as input. The model proposed has been fitted and validated for 13 major allergenic taxa ( Alnus , Artemisia , Betula , Castanea , Corylus , Cupressaceae, Olea , Plantago , Platanus , Populus , Poaceae, Quercus and Tilia ) in different areas of France and Spain. The model has been integrated into a freeware called PPF (Positive Pollen Forecast), which will be made available from the 5 th Framework EU project POSITIVE web page at: http://www.forst.tu-muenchen.de/LST/METEOR/positive/. [ABSTRACT FROM AUTHOR]

Summary 1The fossil pollen record of Cañada de la Cruz in the Segura mountains of southern Spain yields insights into high-elevation vegetational dynamics over the last c . 8320 years. Phases of xerophytic grassland alternate with high-mountain open pine forests and expansion of deciduous forests and Mediterranean scrub at lower altitudes. 2Longer-term stable vegetation patterns are interrupted by multidecadal to century-scale shifts at about 7770, 3370, 2630, 1525 and 790 years BP. 3Some of the vegetation types have no modern analogues and represent high-altitude remnants of widespread last-glacial xerophytic communities. Other species patterns, characteristic of current scrub associations, appeared only within the last 800 years. 4The sequence fits within the regional context of a generally wet mid-Holocene (c . 7700–3300 years BP) characterized by spread of mesophilous vegetation, between drier conditions characterized by greater abundance of xerophytes. 5The pollen record and current ecological studies on high-elevation vegetation of Mediterranean Spain suggest that control of vegetation is primarily climatic although grazing pressure, which would have pushed vegetation over a threshold for change, cannot be discounted. [ABSTRACT FROM AUTHOR]

Pollen analysis from a 14.1 m core recovered from a valley mire at Espinosa de Cerrato (Palencia, Spain), suggests that Pinus woodland has dominated this area of the Northern Meseta throughout almost the entire Holocene, in contrast to many other locations in Iberia where early-Holocene conifer woodland was progressively replaced by deciduous taxa. This unique pattern of vegetation development is attributable to a combination of continental climate, edaphic conditions of these Mesetas, and perhaps fire. These data suggest that vegetation in this area has been remarkably stable over an extended timescale and that arguments concerning Pinus communities not being native in the region are unfounded. Anthropogenic impact can be detected at c. 4500 [sup 14C] yr BP, affecting evergreen Quercus woodlands, and between c. 3000 and 2000 [sup 14]C yr BP affecting Pinus woodlands. The pine forests were replaced by plant communities resembling the present-day landscape (shrubs and cereals) from c. 1500 [sup 14]C yr BP. [ABSTRACT FROM AUTHOR]

Percentage and concentration pollen diagrams are presented for two cores (taken 5 m apart) at an upper Pleistocene and Holocene site at Navarres (Valencia, eastern Spain). Chronological information is provided by an internally consistent radiocarbon dating series that extends from c. 20700 to 3075 yr BP. The results highlight the dangers of relying on a single core in interpreting the patterns of variation of particular taxa. Significant palynological differences, seemingly locational, are described between the two cores. The upper Pleistocene records accords well with the widely recognized European sequence of (a) upper Pleniglacial (b) Bölling-Allerod warm period, and (c) Younger Dryas crisis. However, the sequence does not show disruption of vegetation patterns following the commencement of the Holocene, and Pinus continues to be dominant up to c. 5500 6000 yr BP. Later, there is evidence for Quercus forest, mesophilous trees, and xerosclerophyllous Mediterranean vegetation, which is coincident with eutrophication of the study site. These vegetation changes are discussed in the context of anthropogenic disturbance by Neolithic people, competitive exclusion, and climatic change. [ABSTRACT FROM AUTHOR]