Knowledge of the direct role humans have had in changing the landscape requires the perspective of historical and archaeological sources, as well as climatic and ecologic processes, when interpreting paleoecological records. People directly impact land at the local scale and land use decisions are strongly influenced by local sociopolitical priorities that change through time. A complete picture of the potential drivers of past environmental change must include a detailed and integrated analysis of evolving sociopolitical priorities, climatic change and ecological processes. However, there are surprisingly few localities that possess high-quality historical, archeological and high-resolution paleoecologic datasets. We present a high resolution 2700-year pollen record from central Italy and interpret it in relation to archival documents and archaeological data to reconstruct the relationship between changing sociopolitical conditions, and their effect on the landscape. We found that: (1) abrupt environmental change was more closely linked to sociopolitical and demographic transformation than climate change; (2) landscape changes reflected the new sociopolitical priorities and persisted until the sociopolitical conditions shifted; (3) reorganization of new plant communities was very rapid, on the order of decades not centuries; and (4) legacies of forest management adopted by earlier societies continue to influence ecosystem services today. Published in: Scientific Reports 8 (2018) 2138 https://www.nature.com/articles/s41598-018-20286-4

a number of recent paleoenvironmental studies have argued that abrupt changes in climate have been the primary cause for societal collapse. Many social scientists, including anthropologists and environmental historians, reject environmental explanations as deterministic and overly simplistic. they argue that socio-political decisions contribute to environmental change and that efforts to study societal vulnerability within a human-environment system must include analysis of complex social structures. there is a gap in our understanding of how past societies responded to climate change because there are very few interdisciplinary studies that integrate both physical and behavioral sciences in paleoenvironmental reconstructions. While there is a general sense that modern societies are more insulated than pre-industrial societies from the effects of climate change, this may not prove to be true. a more complete understanding of how both natural and human-caused changes have affected the environment in the past can potentially guide decisions aimed at promoting future sustainability. here we present a project funded by the united states National science foundation that will explicitly integrate paleoenvironmental reconstruction with socioeconomic history in a local context to identify linkages between social and environmental change associated with climate variability.

A number of recent paleoenvironmental studies have argued that abrupt changes in climate have been the primary cause for societal collapse. Many social scientists, including anthropologists and environmental historians, reject environmental explanations as deterministic and overly simplistic. They argue that socio-political decisions contribute to environmental change and that efforts to study societal vulnerability within a human-environment system must include analysis of complex social structures. There is a gap in our understanding of how past societies responded to climate change because there are very few interdisciplinary studies that integrate both physical and behavioral sciences in paleoenvironmental reconstructions. While there is a general sense that modern societies are more insulated than pre-industrial societies from the effects of climate change, this may not prove to be true. A more complete understanding of how both natural and human-caused changes have affected the environment in the past can potentially guide decisions aimed at promoting future sustainability. Here we present a project funded by the United States National Science Foundation that will explicitly integrate paleoenvironmental reconstruction with socioeconomic history in a local context to identify linkages between social and environmental change associated with climate variability.

Small lakes in low relief areas are atypical candidates for studies on paleoseismicity, but their sediments can contain seismically induced event layers (seismites) generated through strong ground shaking, sediment transport, hydrological reorganization and/or changes in groundwater chemistry and flow. Lakes Lungo and Ripasottile are shallow lakes (<10 m deep) located in the tectonically active Rieti Basin in the central Apennines, Italy, where strong normal faulting earthquakes (Mw 6.5 to 7.0) regularly occur. Sediment cores from these lakes provide paleoseismic indicators for the past~1000 years. Sedimento-logical and geochemical analysis reveals four event layers identified in both lakes that correspond with documented large-scale earthquakes in 1298, 1349, 1639, and 1703 AD. Chronological correlation between earthquakes and paleoseismic features is reliable because of the resolution of sediment dating available for the studied cores. The common physical structure is a physically homogenous bed (homogenite) of re-suspended sediment consisting of a denser, high magnetic susceptibility (k) clastic base, with organic matter concentrated above. Co-seismic to post-seismic chemical signatures are associated with some event layers and may represent abrupt or transient shifts to a groundwater-dominated system, or permanent changes in groundwater flow and/or spring discharge. Excursions in d 13 C org may represent disruptions or changes in carbon source. Not all event layers show the same features, a result attributed to differences in seismic processes as well as the lake attributes, and anthropogenic modification. The observations made here may provide a new means of detecting pale-oseismicity and may be applied to other low relief lakes in seismically active areas.

Summary. New data from 45 sediment cores, 35 14C datings and numerous pollen analyses were considered for improving the understanding of the stratigraphy of the Tiber River delta plain. Bottom to top, the three recognized units pointed to the following environments: i) continental shelf with fairly noticeable siliciclastic input, ii) coastal plain with spread lagoons and sandy-gravelly beaches and, iii) a capping complex and mostly a paralic sediment suite which records the landscape evolution over the last 18 kyr. The study area, fully emerged until 13 kyr BP, is characterized by the deep and narrow valley incised by the Tiber River during the last glacial sea level low stand. Following its origin the valley underwent partial submersion by sea-water while Tiber River was building up a seaward retrograding bay-head delta. Beginning from 8 kyr BP this feature progradated and at 6 kyr BP changed into a wave-dominated delta which originated a strand plain with two coastal lakes. In Roman times, the most important harbour of the antiquity was built close to the Tiber River mouth. During the Renaissance, an enhanced progradation phase shaped a landscape akin to the present one, apart from some minor changes subsequent to the reclamation of coastal ponds and relic marshes in modern times. The results herein discussed confirm that the post-glacial sea level rise and the Tiber River solid discharge were the two antithetic mechanisms responsible for the landscape evolution of the deltaic area. However, during the last transgression even the antecedent topographhy played an important role, and since Neolithic times the effects of the anthro-pogenic impact were also noticeable. Zusammenfassung. Eine Teilrevision der Stratigrafie der Tiberdeltaebene wurde durch die Analyse von 45 neuen Bohrungen, 35 neuen Radiokohlenstoffdatierungen und eine in dieser Gegend zum ersten Mal durchgefuhrte Pollenanalyse ermoglicht. Es wurden drei stratigra-fische Einheiten erkannt, die von Diskordanzen getrennt sind. Die untere Einheit weist eine siliko-klastische Sedimentation des Kontinentalschelfs aus, die man dem Mittleren-Oberen Pliozan zuschreiben kann. Die obere Einheit bildete sich auf Grund der Landschaftsentwicklung wahrend der letzten 18.000 Jahre. Das heutige der Tiberdeltaebene entsprechende Gebiet war bis vor etwa 13.000 Jahren Festland, von einem engen Tal gekennzeichnet, das der Tiber wahrend des Wurmmaximums tief eingeschnitten hatte. Von 13.000 bis 7.000 Jahren v. h. wurde das Tal zum Teil vom Meer uberschwemmt, so dass eine Bucht entstand. Hier akkumulierte der Tiber ein Delta, das lange Zeit eine regressive Tendenz zeigte. Vor ungefahr 8.000 Jahren fand eine Wende statt. Fortschreitend veranderte sich das Delta von einem bay-head zu einem wave-dominated Delta. Ungefahr vor 6.000 Jahren begann die Entwicklung einer Strandebene (strand-plain), meerwarts durch zwei grofie Strandseen abgegrenzt. Vor etwa 2.500 Jahren grundeten die Romer die Kolonie Ostia an der Tibermundung. Sie nutzten die Seen fur die Salz-gewinnung. Wahrend des 1. und 2. Jh. n. Chr. bauten sie nicht weit nordlich der Flussmundung das grofite und wichtigste Hafensystem der romischen Welt. Wahrend der Renaissance fand ein neues starkes Vorrucken der Strandlinie statt. Die romischen Hafen versandeten und die Landschaft wurde immer mehr der heutigen ahnlich, besonders nach der Trockenlegung (19. Jh.) der alten Strandseen. Im Laufe der letzten 18.000 Jahre war die Interaktion des postglazialen Meeresspiegelanstieges mit der sedimentaren Zufuhr des Tibers der wichtigste Grund fur die Land-schaftsentwicklung. Die Tatigkeit des Menschen ist jedoch seit dem Neolithikum ein immer wichtiger werdender Faktor der Landschaftsveranderung geworden. Resumé. Une partielle révision de la stratigraphie de la plaine du delta du Tibre a été possible au moyen de 45 carottages, 35 nouvelles datations par le 14C et analyse pollinique. On a reconnues trois unités stratigraphiques limitées par surfaces de discordance stratigraphique. L’unité inférieure montre une sédimentation du plateau continentale pendant le Pleistocène inférieur. L’unité centrale met en évidence une plaine cotière, avec des lagunes et des plages sableuses -graveleuses, développées pendant le Pléistocène moyen et supérieur. L’unité supérieure enregistre l’évolution du paysage pendant les derniers 18 kyr. La zone reste complètement découverte, jusqu’à 13 kyr BP, et est caractérisée par une vallée fluviale étroite et profonde, gravée du fleuve Tibre dans la période wurmienne. Entre 13 et 7 kyr BP, la vallée fut partiellement inondée par la mer, et le fleuve Tibre commenca à construire un delta de fond de baie rétrogradant. Environ à 8 kyr BP le delta de fond de baie s’avanca en direction de la mer et il est progressivement passé à un delta en pointe après 6 kyr BP et se développe une plage progradée qui barre deux petits lacs cotiers. Les Romains s’installent dans la zone d’embouchure et construirent le plus grand port de l’antiquité. pendant la Renaissance une nouvelle phase intense de progradation commence et le paysage devient comme dans le présent. L’interaction entre l’élévation du niveau marine postglacial et le débit solide du fleuve Tibre a été le principal motif de l’évolution du paysage dans les derniers 18 kyr. De tout facon, l’activité humaine dans la période historique devient un facteur toujours plus important dans la modification du paysage.

The fluvial harbour of Aquileia (Italy), one of the most important Roman trading centres in the Mediterranean, was abandoned after the city's destruction in 452 AD. The deserted harbour evolved into a swamp surrounded by a floodplain that has recorded the anthropogenic, environmental and climatic pressures that have occurred during the last 1500 years in the northern Adriatic. Focusing on the period since 500 AD, we here reconstruct the area's long-term ecosystem dynamics. We show that ecosystem dynamics mainly mirror the climate phases of the pre-industrial era. After the Roman era, anthropogenic activities (agriculture, pasture and fire activity) declined in scope and amplitude and are chronologically limited (from the late 7th to the early 13th centuries AD), acting as a background pressure on ecosystems. The main non-human impacts recorded by ecosystems correspond to the Late Antique Little Ice Age and the Pre-industrial Little Ice Age. The temperatures reconstructed for the Medieval Climate Anomaly are close to those recorded for the 20th century AD but they differ from the 21st century AD. Aquileia shows that ancient harbours are key areas to understand how climate and human societies have shaped northern Adriatic environments since the post-Roman period.

The paleoecology of the Pecora Valley, Tuscany

Charcoal analysis, applied in sediment facies analysis of the Pecora river palaeochannel (Tyrrhenian 23 southern Tuscany, Italy), detected the occurrence of past fire events in two different fluvial 24 landforms at 800–450 BC and again at AD 650–1300. Taking place in a central Mediterranean 25 district adequately studied through palaeoenvironmental and archaeological research, the 26 investigation determined land changes, time phases and socio-economic driving forces involved in 27 dynamic processes of fire. The fire sequences had purely anthropogenic origins and was linked to 28 forest opening and reduction by local communities. Introduced by the Etruscans, fires dated to 800–29 450 BC involved mainly the forest cover on the hilly slopes, ensuring agricultural exploitation. 30 From AD 650, fires contributed to Medieval upstream reclamation and vegetation clearing of flat 31 swamplands. From AD 850 to 1050, the use of fire spread over a wider area in the river valley, 32 increasing ...

Earlier studies on Holocene fills of upland lakes (Lago Forano and Fontana Manca) in northern Calabria, Italy, showed that these hold important palaeoecological archives, which however remained poorly dated. Their time frame is improved by new 14C dates on plant remains from new cores. Existing pollen data are reinterpreted, using this new time frame. Two early forest decline phases are distinguished. The earliest is linked to the 4.2 kyr BP climatic event, when climate became distinctly drier, other than at Lago Trifoglietti on the wetter Tyrrhenian side, where this event is less prominent. The second is attributed to human impacts and is linked to middle-Bronze Age mobile pastoralism. At Fontana Manca (c. 1000 m a.s.l.), it started around 1700 BC, in the higher uplands a few centuries later (Lago Forano, c. 1500 m a.s.l.). In the Fontana Manca fill, a thin tephra layer occurs, which appears to result from the AP2 event (Vesuvius, c. 1700 BC). A third, major degradation phase dates...

The palynological study of the lacustrine sediments from Lagaccione, a maar-lake near Lago di Bolsena in central Italy, has provided a palaeoenvironmental record for the last 100,000 years. The chronology of the sequence is based on sixteen radiocarbon dates and a tephra layer at the base of the St Germain II s.l. The pollen record, starting during the St Germain I forest phase and ending about 3000 years ago, shows that remarkable changes occurred in the floristic composition, in the structure of the vegetation and in the plant biomass, including also long-lasting periods of open woodlands, often with an appreciable floristic diversity, during the last pleniglacial. Three new vegetational oscillations (Etruria I, Etruria II and Etruria III), characterized by a well-defined vegetation composition and dynamics, have been recognized after the St Germain I forest phase and before the middle pleniglacial interstadials. New evidence has been obtained for a significant diffusion of deciduous trees in the Italian peninsula during the late-glacial.

Pollen and algae microfossils preserved in sediments from Pyramid Lake, Nevada, provide evidence for periods of persistent drought during the Holocene age. We analyzed one hundred nineteen 1-cm-thick samples for pollen and algae from a set of cores that span the past 7630 years. The early middle Holocene, 7600 to 6300 cal yr B.P., was found to be the driest period, although it included one short but intense wet phase. We suggest that Lake Tahoe was below its rim for most of this period, greatly reducing the volume and depth of Pyramid Lake. Middle Holocene aridity eased between 5000 and 3500 cal yr B.P. and climate became variable with distinct wet and dry phases. Lake Tahoe probably spilled intermittently during this time. No core was recovered that represented the period between 3500 and 2600 cal yr B.P. The past 2500 years appear to have had recurrent persistent droughts. The timing and magnitude of droughts identified in the pollen record compares favorably with previously publi...

Late-glacial (17–11 cal ka BP) pollen records from midwestern North America show similar vegetation trends; however, poor dating resolution, wide-interval pollen counts, and variable sedimentation rates have prevented the direct correlation with the North Atlantic Event Stratigraphy as represented in the Greenland ice-core records, thus preventing the understanding of the teleconnections and mechanisms of late-Quaternary events in the Northern Hemisphere. The widespread occurrence of late-glacial vegetation and climates with no modern analogs also hinders late-glacial climate reconstructions. A high-resolution pollen record with a well-controlled age model from Crystal Lake in northeastern Illinois reveals vegetation and climate conditions during the late-glacial and early Holocene intervals. Late-glacial Crystal Lake pollen assemblages, dominated by Picea mariana and Fraxinus nigra with lesser amounts of Abies and Larix, suggest relatively wet climate despite fluctuations between colder and warmer temperatures. Vegetation changes at Crystal Lake are coeval with millennial-scale trends in the NGRIP ice-core record, but major shifts in vegetation at Crystal Lake lag the NGRIP record by 300–400 yr. This lag may be due to the proximity of the Laurentide ice sheet, the ice sheet's inherent slowness in response to rapid climate changes, and its effect on frontal boundary conditions and lake-effect temperatures.

This study presents the first Late Holocene marine pollen record (core ND2) from SE Sicily. It encompasses the last 3000 years and is one of the most detailed records of the south-central Mediterranean region in terms of time resolution. The combined approach of marine palynology and historical ecology, supported by independent palaeoclimate proxies, provides an integrated regional reconstruction of past vegetational dynamics in relation to rapid climatic fluctuations, historical socio-economic processes, and past land-use practices, offering new insights into the vegetation history of SE Sicily. Short-term variations of sparse tree cover in persistently open landscapes reflect rapid hydroclimatic changes and historical land-use practices. Four main phases of forest reduction are found in relation to the 2.8 ka BP event, including the Late Antique Little Ice Age, the Medieval Climate Anomaly, and the Little Ice Age, respectively. Forest recovery is recorded during the Hellenistic an...

Palynological, sedimentological and geochemical analyses performed on the Villarquemado paleolake sequence (987 m a.s.l, 40°30′N; 1°18′W) reveal the vegetation dynamics and climate variability in continental Iberia over the last 13,500 cal yr BP. The Lateglacial and early Holocene periods are characterized by arid conditions with a stable landscape dominated by pinewoods and steppe until ca. 7780 cal yr BP, despite sedimentological evidence for large paleohydrological fluctuations in the paleolake. The most humid phase occurred between ca. 7780 and 5000 cal yr BP and was characterized by the maximum spread of mesophytes (e.g., Betula, Corylus, Quercus faginea type), the expansion of a mixed Mediterranean oak woodlandwith evergreen Quercus as dominant forest communities and more frequent higher lake level periods. The return of a dense pinewood synchronouswith the depletion of mesophytes characterizes the mid-late Holocene transition (ca. 5000 cal yr BP) most likely as a consequence of an increasing aridity that coincides with the reappearance of a shallow, carbonate wetland environment. The paleohydrological and vegetation evolution shows similarities with other continental Mediterranean areas of Iberia and demonstrates a marked resilience of terrestrial vegetation and gradual responses to millennialscale climate fluctuations. Human impact is negligible until the Ibero-Roman period (ca. 2500 cal yr BP) when a major deforestation occurred in the nearby pine forest. The last 1500 years are characterized by increasing landscape management, mainly associated with grazing practices shaping the current landscape.

Numerous researchers discuss of the collapse of civilizations in response to abrupt climate change in the Mediter-ranean region. The period between 6500 and 5000 cal yr BP is one of the least studied episodes of rapid climate change at the end of the Late Neolithic. This period is characterized by a dramatic decline in settlement and a cultural break in the Balkans. High-resolution paleoenvironmental proxy data obtained in the Lower Angitis Valley enables an examination of the societal responses to rapid climatic change in Greece. Development of a lasting fluvio-lacustrine environment followed by enhanced fluvial activity is evident from 6000 cal yr BP. Paleoecological data show a succession of dry events at 5800–5700, 5450 and 5000–4900 cal yr BP. These events correspond to incursion of cold air masses to the eastern Mediterranean, confirming the climatic instability of the middle Holocene climate transition. Two periods with farming and pastural activities (6300–5600 and 5100–4700 cal BP) are evident. The intervening period is marked by environmental changes, but the continuous occurrence of anthropogenic taxa suggests the persistence of human activities despite the absence of archaeological evidence. The environmental factors alone were not sufficient to trigger the observed societal changes.

As part of the Changing the Face of the Mediterranean Project, we consider how human pressure and concomitant erosion has affected a range of Mediterranean landscapes between the Neolithic and, in some cases, the post-medieval period. Part of this assessment comprises an investigation of relationships among palaeodemographic data, evidence for vegetation change and some consideration of rapid climate change events. The erosion data include recent or hitherto unpublished work from the authors. Where possible, we consider summed probabilities of 14C dates as well as the first published synthesis of all known optically stimulated luminescence dated sequences. The results suggest that while there were some periods when erosion took place contemporaneously across a number of regions, possibly induced by climate changes, more often than not, we see a complex and heterogeneous interplay of demographic and environmental changes that result in a mixed pattern of erosional activity across the...

The history of vegetation in the Italian peninsula during the last 2000 years was shaped by a complex interplay of several factors, including the history of human societies, changes in land use, and the succession of climate events. In order to disentangle these factors, we present a multidisciplinary record from a marine core collected in the Gulf of Gaeta, interpreted in the light of other palaeoenvironmental records from Tyrrhenian Italy. Pollen records, complemented by new data on Non-Pollen Palynomorphs (NPPs) and microcharcoal, are used to reconstruct changes in the vegetational landscape, stock-breeding activities, fire, and land use. Foraminiferal and oxygen isotope data provide independent information on climate changes. NAO-index and sunspot data support the interpretation of changes in atmospheric circulation. In this paper, by examining the effect of climate and human activity on the landscape during a series of periods of the last 2000 years, representing cultural or climate phases (Roman Period, Dark Ages, Medieval Climate Anomaly, Little Ice Age, and Modern Period), we found that human impact produced a general and progressive decline of forest vegetation. However, irrespective of the societal cultural phase, forest declines occurred when negative NAO oscillations induced dry climate, especially during sunspot minima.

Using a combination of pollen, non-pollen palynomorphs (NPPs) and charcoal particle stratigraphies from sediment cores from two sites, along with historical records, we reconstructed paleoenvironmental change in midcoastal California. The San Antonio Creek section contains a discontinuous, Holocene-length record, while Mod Pond includes a continuous late Holocene record. Together the records allow for interpretation of most of the present interglacial. The longer record documents coastal sage scrub and chaparral dominated bywoodland elements early in the Holocene to about 9000 yr ago, a potential decline inwoodland communitieswith drying conditions during the middle Holocene to about 4800 yr ago, and an expansion of coastal sage scrub with grassland during the late Holocene. Evidence for climatic fluctuations during the last 1000 yr at Mod Pond is equivocal, suggesting that the Medieval Climate Anomaly–Little Ice Age had modest impact on the Mod Pond environment. However, evidence of significant environmental change associated with cultural transitions in the 18th–19th centuries is stark. Introduction of non-native plants, establishment of cattle and sheep grazing, missionization of the native population, changes in burning practices during the Spanish period and enhanced cropping activities during North American settlement worked together to substantially modify the mid-California coastal landscape in about a century's time.

It is well-known that the Holocene exhibits a millennial-scale climate variability. However, its periodicity, spatio-temporal patterns and underlying processes are not fully deciphered yet. Here we focus on the central and western Mediterranean. We show that recurrent forest declines from the Gulf of Gaeta (central Tyrrhenian Sea) reveal a 1860-yr periodicity, consistent with a ca. 1800-yr climate fluctuation induced by large-scale changes in climate modes, linked to solar activity and/or AMOC intensity. We show that recurrent forest declines and dry events are also recorded in several pollen and palaeohydrological proxy-records in the south-central Mediterranean. We found coeval events also in several palaeohydrological records from the southwestern Mediterranean, which however show generally wet climate conditions, indicating a spatio-temporal hydrological pattern opposite to the south-central Mediterranean and suggesting that different expressions of climate modes occurred in the two regions at the same time. We propose that these opposite hydroclimate regimes point to a complex interplay of the prevailing or predominant phases of NAO-like circulation, East Atlantic pattern, and extension and location of the North African anticyclone. At a larger geographical scale, displacements of the ITCZ, modulated by solar activity and/or AMOC intensity, may have also indirectly influenced the observed pattern. Understanding the long-term trends and spatial patterns of climate variability in the current interglacial period, the Holocene, is crucial to assess the significance of ongoing climate change and future projections. Furthermore, taking into account the commonality of processes and mechanisms shared by climate models at all timescales, understanding the low frequency (millennial) component of past climate change is ultimately essential for improved predictions on all timescales. While it is well-known that the Holocene exhibits a millennial-scale climate variability, its periodicity, spatio-temporal patterns and underlying processes are not fully deciphered yet.

The overall review of the pre- and protohistoric agrarian traces found at Gricignano d’Aversa/U.S. Navy (CE), in the course of the research held by the Soprintendenza per i BB.AA. della Campania and the Soprintendenza al Museo Nazionale Preistorico Etnografico “L.Pigorini” (1995-2005), has allowed us to describe the structure of land partitioning over about 60 ha. Particularly clear is the consistent pattern of the fields underlying the Early Bronze Age eruption of the “Pomici di Avellino” (1935-1880 a.C., Passariello I. et al. 2009). Anyway, this is the final outcome of a series of agrarian infrastructures which were realized since the advanced Copper Age, over the Phlegrean eruption of Agnano Monte Spina (4130±50 BP, de Vita et al., 1999). The Gricignano case gives us the opportunity to review the available data on the protohistoric agrarian impact in the Piana Campana. In fact, the continuously increasing discoveries of agrarian and settlement traces, lead to the certainty of an intense occupation of the area. The particular fertility of the volcanic soils, combined with a significant input of labour for the infrastructures - such as irrigation and / or drainage ditches, as well as cart-tracks, made possible the intense occupation and exploitation of the territory. This process, properly culminating in the EBA, apparently occurs in continuity with the territory organization identified as for the Copper Age, when open villages were preferentially located in direct contact with the primary arable land, and were subject to periodic dislocations.