The Holocene

The use of cattle labour in antiquity is a worldwide well-discussed topic among researchers as it can shed light on the possible development trajectories of our communities over the past several millennia. Zooarchaeology can play a vital role in illuminating the history of cattle traction through observed pathologies on cattle bones linked to traction activity. Systemic zooarchaeological investigation is still underdeveloped in China, one of the likely early beneficiaries of animal labour exploitation in the world. Here, we apply the pathological index (PI) method, first developed by Bartosiewicz et al. on European assemblages, to Chinese Bronze Age cattle bones. Our results first confirm the wide applicability of the PI method with the involvement of Chinese control samples, which holds the potential to be applied as an effective tool in a larger geographical region. Our results also confirm the importance of cattle traction for the Late Shang states (c. 1300–1046 BC) as previously proposed on the basis of disputed interpretations of oracle bone inscriptions as showing cattle ploughing, but also show that light cattle traction practices likely developed in China in the Bronze Age Erlitou (c. 1750–1530 BC) and Early Shang (c. 1600–1300 BC) periods. Cattle traction use in the Chinese Bronze Age may have facilitated the introduction and subsequent cultivation in China of wheat, an exotic cereal.

The variability of the East Asian summer monsoon (EASM) has far-reaching effects on the global climate system and the environment, and full understanding of the variability and dynamics of the EASM contributes to predictions of its future behavior. Here, we present a well-dated mineralogical and total organic carbon record from a saline inland lake in northern China which provides a robust archive of the EASM evolution since 16.0 cal. ka BP. Our record reveals a series of rapid and frequent millennial-scale climatic fluctuations during the last deglaciation; these fluctuations are documented by changes in the abundances of mirabilite, bloedite, and gypsum, which appear to record the Oldest Dryas, the Bølling-Allerød warm period, and the Younger Dryas. The peak EASM moisture occurred in the early and middle Holocene, which was punctuated by a prominent and abrupt weak monsoon interval that occurred synchronously with the 8.2 cal. ka BP cold event. This moisture maximum was terminated at 6.9–5.9 cal. ka BP by a warm-dry event marked by the deposition of gaylussite. Subsequently, the EASM gradually weakened over the late Holocene. The EASM moisture patterns reconstructed from Anguli-nuur Lake display good consistency with records from northern China, as revealed by a regional comparison; moreover, the recorded changes are synchronous with those of the Indian summer monsoon moisture patterns, as revealed by a comparison with the stalagmite records of southern China. Our reconstruction shows that the EASM has responded broadly to Northern Hemisphere summer insolation forcing on orbital time scales since the last deglaciation; thus, insolation is the primary factor that controls regional hydrological variations in the Asian monsoonal domain. The suborbital-scale events are related to the Atlantic meridional overturning circulation, and a slowdown of this circulation would lead to a southward shift of the intertropical convergence zone and a weakening of the EASM.

Phaistos was one of the most important Minoan palaces in Crete and previous studies have addressed its relationship with the paleo-seashore position during historical times. Here, we reconstruct the environmental evolution of Phaistos from Early Minoan to Roman times. Study of two stratigraphic sections and nine boreholes drilled in the westernmost part of the Messara Plain has revealed the stratigraphy of the Mid- to Late-Holocene sediments. Laboratory analyses comprise granulometry, magnetic susceptibility measurements and identification of mollusks, diatoms and pollen grains. Eighteen radiocarbon dates provide a robust chronostratigraphy. In addition, a geophysical survey (electric resistivity tomography (ERT) method) was conducted to reveal the sub-surface morphology in the coring area. The results reveal that a freshwater lake existed from ca. 2100–2000 BC to ca. 1200–1100 BC, which subsequently became swampland until ca. 700 BC. A lake retreat is identified at ca. 1200–1000 BC and can be interpreted as resulting from the 3.2 cal kyr BP rapid climate change (RCC) dry event, observed elsewhere in the Eastern Mediterranean. Subsequently, from the 7th to the 5th century BC, there was the input of detrital material and fluvial dynamics prevailed until at least Roman times. The origin of the lake and its disappearance are discussed in the context of regional climate change and local tectonic activity, without excluding possible human influences. We also reconstruct the vegetation history for the period from the Late Minoan to the Early Archaic period. Pollen analysis reveals a Mediterranean maquis landscape dominated by Olea, together with hygrophilous vegetation, and highlights a clear transition from limnic to swampy environmental conditions around 1100 BC. The pollen sequence is also important for assessing the impact of the 3.2 cal. kyr BP RCC event and for assessing the possibility of an abrupt discontinuity in human activity around Phaistos after the demise of the Minoan Civilization.

Wave processes are well known for developing spit systems in large or elongated lakes by inducing longshore sediment transport for spit migration, while bathymetric interaction is less studied. In this study, we investigate the combined effects of wave processes, antecedent topography and lake level changes on the development of Holocene spit systems in the Danish lake Mossø. Wave climate prediction and a digital elevation model were used to provide a conceptual model for the development of the spits system, while optically stimulated luminescence (OSL) dating of spit sand and antecedent topography analyzed via boreholes and seismic survey data were used to evaluate effects on spit migration other than wave setting. We found that spit migration stagnated during the Holocene when reaching areas of deeper waters, but continued following shallowing after deep basin infilling with lacustrine sediments. During periods of bathymetrically induced stagnation of prominent spits, less stable or more slowly migrating spits became prominent in the development of the spit system. No clear effects on spit migration caused by lake level fluctuations could be demonstrated. However, such fluctuations may have been important for the stabilization of spits and subsequent development of a major barrier shoreline.

Innovative Computerized co-axial tomography (CAT)-scan methods have been applied to two short cores collected in the southern Caspian Sea, offshore from the Langarud–Rudsar region of Iran, to the east of the Sefidrud delta. Magnetic susceptibility (MS) readings, in association with other lithological criteria, are used to correlate the cores and calibrate to real time. The cores provide a sedimentary record from this largely unstudied region covering the last 200+ years (~1784 to 2008 CE). Three principal lithofacies types were recognized. The more distal locality (T2-3, water depth 117 m) consists entirely of poorly fossiliferous silty muds, whereas the more proximal locality (T2-2, water depth 51 m) contains beds with rich ostracod, gastropod and bivalve assemblages. Peak MS readings occur between ~1872 and 1918 CE and are linked to erosion of sediments deposited during the ‘Little Ice Age’ (LIA) highstands of the Caspian Sea. CAT-scan results reveal the presence of the non-marine Mermia ichnofacies type, which is reported for the first time in the Caspian Sea. Horizontal burrows (feeding structures) by Treptichnus ichnofauna coincide with periods of LIA highstand in Caspian Sea level and suggest low-energy conditions on the marine shelf. Vertical burrows (feeding structures) occur at times of relatively stable, but variable Caspian water levels. Interbedded dark coloured, organic-rich muds and lighter silt-rich layers within the last ~100 years show potential cyclicity which may be linked to climatic and/or river discharge events.

Human activity on arid lands has been related to oases evolution. The ancient Loulan, an important transportation hub of the ancient Silk Road, developed on an ancient oasis on the west bank of the lake Lop Nur in Xinjiang, China. Previous studies and historical documents suggest that the region has experienced dramatic natural environmental and human activity–related changes over time, transitioning from a particularly prosperous oasis to a depopulated zone with harsh environment after about 1500 a BP (before present, where present = AD 1950). Based on systematic radiocarbon (¹⁴C) dating for natural plant remains and archeological sites in the Loulan area, it was revealed that the region re-experienced oasis environment from 1260 to 1450 cal. AD, corresponding to the Yuan–Ming Dynasties, which is the climate transition stage from the ‘Medieval Warm Period’ to the ‘Little Ice Age’, encompassing a series of pulse-like flood events which cannot be identified from lacustrine deposition due to the limits of sampling resolution and dating. It was found that humans re-occupied the Loulan area and built canals to irrigate farmlands during the period. The more habitable hydrological conditions that resulted from these environmental changes present one major reason for the re-emergence of human activities in the Loulan area.

Geomorphological and sedimentary records of Holocene coastal deposits may serve as archives for the local reconstruction of trends in coastal evolution and of the key forcing parameters controlling long-term change. We here present new observations on the sedimentology, chronology, and surface properties of a coupled beach ridge and coastal lagoon system located on the northern shore of San Matías Gulf, NE Patagonia, Argentina. The study is based on remotely sensed data, sediment cores, and a large number of samples dated using optically stimulated luminescence (OSL). The field site is located in a topographical depression within a cliffed shoreline composed of friable sand and gravel stones. The oldest preserved lagoonal deposits formed in the protected inner part of the system c. 2300 years ago. An up to 4-km-wide strandplain prograded rapidly between c. 1000 and 500 years in the more exposed western part of the system. Lagoonal deposition occurred primarily during the last 500 years. The chronology and spatial arrangement of landforms appear to result from a switch-over in sediment delivery probably caused by local implications of major shifts in climate regime. Even though we were not able to identify or benchmark the precise triggers of geomorphological change at Caleta de los Loros, our study presents an example of the potential importance of environmental changes on the rapid and non-linear development of coastal sedimentary systems.

The summer rainfall zone (SRZ) in the South African interior experienced pronounced hydrological and vegetation changes during the Holocene inferred to be driven mainly by shifts in atmospheric and oceanic circulations systems. The exact mechanisms controlling these changes are still debated. To gain better insights into the Holocene environmental changes in the South African SRZ and their driving factors, we analysed compound-specific carbon and hydrogen isotopes of plant wax n-alkanes (δ¹³C_wax and δD_wax) from a marine sediment core covering the last 9900 years. The core has been recovered offshore the mouth of the Orange River, predominantly draining the South African summer rainfall region. Our data indicate a dry early Holocene and a gradual increase of wetter conditions with a higher abundance of C₄ vegetation towards the middle Holocene. Wettest conditions occurred around 3900 cal. yr BP. The last 3900 years were characterised by a gradual aridification overlain by variable wetter conditions. During the ‘Little Ice Age’ (LIA: ca. 640–310 cal. yr BP), relatively dry conditions with elevated C₄ plant contributions occurred. This opposite behaviour, that is, more C₄ plant contribution during drier conditions compared to the remainder of the Holocene, points towards an influence of winter rainfall in the lower Orange River catchment during the late-Holocene and a decline in summer rainfall. We emphasise the importance of changes in the latitudinal insolation gradient (LIG) as a potentially important controlling mechanism for hydrologic and vegetation changes in the SRZ.

Processes behind the shift from hunting-gathering to food production lifestyle are multifaceted and not yet completely understood. The Mediterranean coast of NW Africa provides an eclectic transitional pattern, namely, a very hesitant transition to food production. The distribution and abundance of early Neolithic domesticated species is disparate and region specific. Climate and environmental change have been often considered as an important influencing factor for this transition. This hypothesis was tested using archeological shells of the rocky intertidal gastropod Phorcus turbinatus recovered from the Ifri Oudadane site in NE Morocco. The oxygen isotope composition (δ¹⁸O) of the shell was used to examine whether the hesitant transition to food production was linked to a local climate shift in the Mediterranean Maghreb. Intrashell δ¹⁸O values suggest a marked temperature increase from >7.6 to ~7.0 cal. ka BP, the time when Neolithic innovations first appear on site. An additional increase in temperature from ~7.0 to <6.8 cal. ka BP matches with the beginning of the main occupation phase and the doubtless breakthrough of cultivation at Ifri Oudadane. This apparent warming trend, although considered preliminary, seems to match well with warming tendency observed in several published regional climate proxies. Therefore, a temperature shift may have played a role in the timing and implementation of food production in the area. Last growth episode δ¹⁸O values suggest that shellfish were harvested throughout most of the year, with noticeable intensification during the cooler half of the year. This preliminary pattern was fairly consistent throughout the Epipaleolithic and early Neolithic phases, pointing to a probable near year-round site occupation rather than a single season settlement. Future research on Ifri Oudadane and other NW African archeological records are much needed to assess whether these patterns persist in Morocco and other Epipaleolithic and early Neolithic settlements in the western Mediterranean Maghreb.

The nutrient-poor grasslands of Western Europe are of major conservation concern because land use changes threaten their high biodiversity. Studies assessing their characteristics show that their past and on-going dynamics are strongly related to human activities. Yet, the initial development patterns of this specific ecosystem remain unclear. Here, we examine findings from previous paleoecological investigations performed at local level on European grassland areas ranging from several hundred square meters to several square kilometers. Comparing data from these locally relevant studies at a regional scale, we investigate these grasslands’ spatiotemporal patterns of origin and long-term dynamics. The study is based on taxonomic identification and radiocarbon AMS dating of charcoal pieces from soil/soil sediment archives of nutrient-poor grasslands in Mediterranean and temperate Western Europe (La Crau plain, Mont Lozère, Grands Causses, Vosges Mountains, Franconian Alb, and Upper-Normandy region). We address the following questions: (1) What are the key determinants of the establishment of these nutrient-poor grasslands? (2) What temporal synchronicities might there be? and (3) What is the spatial scale of these grasslands’ past dynamics? The nutrient-poor grasslands in temperate Western Europe are found to result from the first anthropogenic woodland clearings during the late Neolithic, revealed by fire events in mesophilious mature forests. In contrast, the sites with Mediterranean affinities appear to have developed at earlier plant successional stages (pine forest, matorral), established before the first human impacts in the same period. However, no general pattern of establishment and dynamics of the nutrient-poor grasslands could be identified. Local mechanisms appear to be the key determinants of the dynamics of these ecosystems. Nevertheless, this paleoecological synthesis provides insights into past climate or human impacts on present-day vegetation.

In discussions of human-environmental dynamics and climate change, treatments of water usually focus on the problem of drought. Monsoon environments constitute a different set of parameters for landscape interactions because of seasonal episodes of water abundance. In this paper, we evaluate the microscale management of routine and anticipated high-water events for the ancient Indian subcontinent, where people used the monsoon cycle to engage in rice farming that in turn supported the growth of cities. Rice production would have encompassed two fluctuating inputs: rural labor, which may have become scarce when villagers left farmlands to become city dwellers; and water, the quantity of which varies dramatically on both a seasonal basis because of the monsoon and on an occasional basis because of tropical cyclones. The abundance of water (even with its risks of overabundance) encompassed numerous logistical challenges but also permitted high productivity within short distances of urban centers. The case study of the ancient city of Sisupalgarh in eastern India illustrates that high levels of productivity per land area enabled city residents to engage in short-distance economies for food production, while maintaining regional contacts through durable-goods trade to mitigate occasional episodes of crop failure in times of major flooding.

Changes in climate conditions during the Holocene are documented in different parts of South America, showing contrasting responses to global changes. This study was conducted in the wet puna at an elevation of 4040 m a.s.l. on the eastern side of the Cordillera Real in Bolivia near Lake Titicaca. Pollen, charcoal, and stable isotopes in a sediment core collected in the peatland of Escalerani were analyzed. Results revealed environmental changes during the past 7500 yr BP, with an increase in wet climate conditions from 5900 to 4700 cal. yr BP and 3500 to 1300 cal. yr BP, and two dry periods between 4700 and 3500 cal. yr BP and 1300 to 560 cal. yr BP. Changes in hydrological conditions ranged from local changes because of glacier melting to regional changes in annual rainfall variability, related to South American monsoon activity. Moreover, our results highlight the importance of cloud convective activity from the Amazon basin along the adiabatic gradient, which maintained moist conditions at high elevations even during the mid-Holocene dry phase. The last 70 years have been characterized by the degradation of the peatland because of human activity.

Charcoal particles are evidence of past fire events and macro-charcoal particles have been shown to represent local fire events. There are several methods for the preparation and quantification of macro-charcoal particles, none of which have been universally accepted as standard. Very few studies compare methodological differences and no studies to date compare quantification by mass with quantification by volume using image analysis. Using three cores taken from a peatland located in SE Norway, we compare these two established methods using a generalized linear mixed model (GLMM) and a split-plot ANOVA test. We show that charcoal volume (image analysis method) was a better predictor of charcoal mass than charcoal particle number and the same size classes of charcoal as size class distributions were not spatially and temporally correlated. Although there is still a need for a common and unifying method, our results show that quantification of charcoal particles by image analysis including size (e.g. height in mm) and area (mm²)/volume (mm³) measurements provides more significant results in cross-site or multiple-site studies than quantifications based on particle number. This has implications for the interpretation of charcoal data from regional studies that are used to model drivers of wildfire activity and environmental change in boreal–temperate landscapes during the Holocene.