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The synthetic analysis of several pollen records from sub-Mediterranean lowland Pre-Pyrenean regions evidences expansion of forests during the Early Holocene in Northeastern Iberia and the establishment of dense deciduous broadleaf forests during the Holocene Climate Optimum. Pollen records show the broadleaf deciduous forests resilience against cooling phases during the Mid-Holocene period, with slight regressions of oak woodlands and expansion of conifers or xerophytic taxa contemporary to some cooling episodes (i.e. 8.2 and 7.2 kyr cal. BP). Major vegetation changes influenced by climate change occurred in the transition to the Late Holocene, in terms of the start of a succession from broadleaf deciduous forests to evergreen sclerophyllous woodlands. The lack of evidence of previous occupation seems to support the Neolithisation of the NE Iberian Peninsula as a result of a process of migration of farming populations to uninhabited or sparsely inhabited territories. In that context, remarkable changes in vegetation were recorded from 7.3 kyr cal. BP onwards in the Lake Banyoles area, where the establishment of permanent farming settlements caused the deforestation of oak woodlands. In La Garrotxa region, short deforestation episodes affecting broadleaf deciduous forests, together with expansion of grasslands and presence of Cerealia-t were documented in the period 7.4–6.0 kyr cal. BP. Finally, in the coastal area, where less evidence of Early Neolithic occupations is recorded, evidence of Neolithic impact is reflected in the presence of Cerealia-t in 6.5–6.2 kyr cal. BP, but no strong human transformation of landscape was carried out until more recent chronologies. [ABSTRACT FROM AUTHOR]

The tempo and mode of colonization of the Iberian Peninsula (IP) by Cannabis sativa , its further internal spreading and the potential cultural and environmental factors involved remain unknown. The available continental-wide European meta-analyses using pollen and archeological evidence account for only a few IP sites, insufficient for a sound assessment. This paper presents a nearly comprehensive database of almost 60 IP sites with palynological evidence of Cannabis and analyzes the corresponding spatiotemporal patterns. The first scattered records of this pollen type date from the Middle and Upper Paleolithic (150–12 kyr BP) and would have entered the IP by maritime Mediterranean or terrestrial continental pathways, or both. A first burst of introductions, probably in a cultivated form, would have occurred during the Neolithic (7–5 kyr BP) using similar paths. Human participation in these Neolithic introductions remains unclear but cannot be dismissed. A period of reduced Cannabis arrivals (mostly via maritime pathway) occurred between the Chalcolithic and the Roman Epoch (4.5–2 kyr BP), when the innermost parts of the IP were colonized (Late Bronze). A second, likely anthropogenic, introduction acceleration took place in the Middle Ages (1.5 kyr BP onward) using the Mediterranean and the continental pathways. Maximum cultivation and hemp retting activity was recorded during the Modern Ages (16th-19th centuries), coinciding with the increased demand of hemp fiber to supply the Spanish royal navy for imperial expansion and commerce. A potential link between Cannabis colonization/introduction bursts and climatic warmings has been observed that should be tested with future studies. Regional moisture variations seem to be less influential. Further efforts to enhance and improve the database used in this study are encouraged. The results of this paper should be compared with archeological and historical evidence to clarify the role of human migrations and cultural changes in the historical biogeography of Cannabis in the IP. • Cannabis entered the Iberian Peninsula (IP) as soon as ∼150 kyr BP likely by wild dispersal. • The first burst of introductions occurred in the Neolithic (7–5 kyr BP). • Spreading across the whole IP occurred the Chalcolithic-Roman periods (4.5–2 kyr BP). • An introduction acceleration took place in the Middle Age (1.5 kyr BP onward). • Maximum hemp cultivation/retting occurred in Modern Ages (16th-19th centuries). • Colonization/introduction bursts coincided with warmer climatic phases. [ABSTRACT FROM AUTHOR]

The Pliocene Villarroya basin fill consists of lacustrine and alluvial deposits over 100 m thick. The lacustrine deposits, up to 30 m thick, comprise three sequences. The two lower sequences consist of profundal, laminated deposits formed by mostly terrigenous facies that are overlain by charophytic carbonates and varves. The uppermost, third sequence made up of massive bioturbated mudstones corresponds to a very shallow lacustrine–palustrine environment. Bulk mineralogy comprises carbonates, clay minerals, quartz and feldspars. The carbonates are: exogenic, biogenic calcite and biogenic aragonite. Biogenic calcite constitutes ostracod shells and charophyte stem encrustations, whereas aragonite forms gastropod shells and, in some varve intervals, charophyte encrustations. The clay minerals are illite, kaolinite, palygorskite, chlorite and paragonite, which are inherited from source rocks, and smectite and interstratified clays, which are probably formed in the soils of the source area. Variations in clay mineralogy reflect the interplay between the climate, tectonic rejuvenation and the paleogeography of the basin.The pollen assemblages indicate significant variations in climate: a first phase of varying climate was followed by cool-temperate and sub-humid phases that culminated in a temperate and dry episode, which is recorded in the lower part of the second lacustrine sequence. This was succeeded by a marked warm and humid episode, which may be correlated with the Mid-Pliocene warmth about 3.0 Ma and the subsequent cooling phase, which is recorded in the upper, third sequence.In the two lower sequences (profundal lacustrine deposits), ostracods indicate oligosaline to mesosaline waters with salinity variations and some warm and Na–Cl episodes. Molluscs are characterized by hydrobiids, suggesting a salinity stress. In the upper, palustrine deposits, the ostracods and aquatic mollusc assemblages indicate fresh, cold waters. Faunal records indicate that changes in salinity do not correlate with climate, suggesting phases of significant saline inputs to the lake which were recorded in the lower first sequence and in the upper part of the second sequence.The lacustrine sequence of Villarroya record pronounced variations in climate and in the lacustrine environment. However, there are no consistent relationships between the climate conditions inferred from the pollen data and the sedimentary record of the environmental changes, showing that other factors, especially tectonics, have exerted an influence on the paleoenvironmental evolution, and on the sedimentary record of the Pliocene Villarroya lake. [Copyright &y& Elsevier]