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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]

Vegetal remains are considered labile structures that quickly become decayed in ecosystems. However, certain lignified tissues (woody plants) can largely resist decomposition, becoming sometimes exceptionally well preserved. At the Upper Cretaceous site of 'Lo Hueco' (Cuenca, Spain), those woody remains (trunks and branches) with resinous material in the inner tracheids and parenchyma cells that were buried rapidly under anoxic conditions experienced a low degree of maturation, becoming exceptionally well preserved. Those woody remains deposited under oxic conditions (sub-aerial or sub-aquatic exposure) were more intensely biodegraded and subsequently carbonified, partially or completely mineralized in gypsum and covered by a ferruginous crust. These two modes of preservation are scarce, with silicification or carbonification processes much more common, and both can be considered as 'exceptional preservation'. Other vegetal remains, such as carbonified leaves, stems and roots, were collected in the site. The different modes of preservation depend directly on: depositional micro-environment (sandy distributary channel, muddy flood plain); and type (trunk, branch, stem, leave, root) and state (presence or absence of resinous material) of the material. The great abundance and diversity of fossils in 'Lo Hueco' identify it as Konzentrat-Lagerstätten, sequentially formed by alternated events of flooding and drying depositional events, but the exceptional quality and rarity of determinate vegetal macroremains preservation suggest that certain deposits of this site can be considered as conservation deposits. [ABSTRACT FROM AUTHOR]

Abstract: The sediments of La Rinconada mine (Ribesalbes-Alcora basin, Province of Castellón, Eastern Spain) have yielded one of the Early Miocene''s richest megafloral assemblages in the southwestern Mediterranean. At this site, we have found a large amount of leaf compressions and impressions without preserved cuticle. We have identified a total of 31 species of vascular plants: 1 horsetail, 1 fern, 4 conifers, 23 arboreal or bushy dicotyledoneous angiosperms and 2 monocotyledoneous angiosperms. These fossils reveal the presence during the first half of the so-called Miocene Climatic Optimum of a fluvial-lacustrine flora with well diversified mixed broadleaved deciduous and coniferous taxa. Arctotertiary elements dominate the assemblage, whereas Palaeotropical taxa scarcely occur. The occurrence of Trigonobalanopsis exacantha and Trigonobalanopsis rhamnoides is conspicuous as these are common in humid subtropical evergreen vegetation during the climatic optima in the European Oligocene and Miocene. In the La Rinconada outcrop, there is a noteworthy lack of some taxa such as Juglandaceae, Nyssa and Quercus in comparison with other contemporaneous European floras. [Copyright &y& Elsevier]

Abstract: This paper reports on analysis of plant macrofossils in aeolian deposits exposed in El Asperillo cliff in the Province of Huelva. A significant find of a large number of macrofossils of Pinus (Pinus pinaster Ait. and Pinus nigra Arnold) makes a major contribution to our understanding of the role of Pine in the Upper Pleistocene landscapes of Iberia. P. pinaster Ait. and P. nigra Arnold, are meso-microthermic species and inhabited valleys excavated in aeolian sediments mainly deposited during OIS 4 and OIS 3 (based on OSL and radiocarbon ages). Their presence in these valleys during the last part of OIS4 and OIS 3 reflects a significant fall in temperature during certain periods of these isotopic stages and helps us better understand the response of coastal dynamics to climate change. [ABSTRACT FROM AUTHOR]

Abstract: The Cal Guardiola site, discovered during the construction of an office building in the centre of Terrassa (Province of Barcelona, NE Spain), is home to one of the richest deposits of lower–middle Pleistocene flora in the Iberian Peninsula. The site contains a large quantity of plant macroremains, including non-carbonised wood, in an exceptional state of preservation. In this work, 100 wood fragments were analysed along with 25 pollen samples and 2 coprolites, all from the same horizon. These remains revealed the presence of a mixed deciduous forest with significant numbers of Quercus (Quercetum mixtum). Thermophilous, meso-hygrothermophilous and river forest species were also present, including some taxa rarely recorded for the Pleistocene, e.g., the mesocratic group of species represented by Juglans, Carya and Platanus. Fossil wood of Aesculus was also identified; this is the first Pleistocene reference of this species in Iberia. In this open Mediterranean forest, several remarkable gymnosperms were present. For example, Pinus haploxylon-type pollen was identified, demonstrating the survival of this group of conifers during the lower Pleistocene in the Iberian Peninsula. Pollen of Taxodiaceae was also found — the first reference of this family for the Iberian Pleistocene-showing these taxa survived on the Peninsula until the lower–middle Pleistocene transition. Warm-temperate and humid conditions prevailed during this interval; clear indications of an interstadial episode were observed. [Copyright &y& Elsevier]