Groundwater for Sustainable Development

Cueva de la Dehesilla, a cave in the province of Cádiz in southern Spain, was occupied throughout the Neolithic in the 6th to 4th millennia bce. Within this sequence, recent archaeological excavations have identified stratigraphic levels and contexts belonging to domestic and funerary activities dated to the Early, Middle and Late Neolithic periods. In this paper, we present the results of the wood charcoal remains from excavation areas C003, C005 and C006. The results are consistent with the Mediterranean taxa identified from other sites throughout the region and confirm the use of a wide range of woodland resources: Arbutus unedo, cf. Artemisia sp., Erica arborea, Ericaceae, Fraxinus sp., Juniperus sp., Olea europaea var. sylvestris/cf. Olea europaea var. sylvestris, Pinus pinea/pinaster, Pinus sp., Pistacia lentiscus, Quercus (deciduous and evergreen), Rhamnus/Phillyrea, monocotyledon and indeterminate angiosperm and gymnosperm taxa. The widest range of taxa, including trees, is from the Early Neolithic to early Middle Neolithic remains. The diversity of taxa decreases notably in the late Middle Neolithic and Late Neolithic, and becomes mainly shrubs. This pattern is consistent with the modification of the landscape as a result of woodland clearance, previously suggested by the pollen analyses at the site, and documented on a wider scale throughout the region. The procurement of firewood around La Dehesilla appears to have been opportunistic and conditioned by the resources that were available in the immediate landscape. At present, there is mixed evidence for the influence of good burning quality on the choice of fuel, as is illustrated by the concentrated charcoal remains found in particular domestic and ritual funerary contexts.

The impact of the 4.2 ka event on the subsistence of Jomon hunter–gatherers was studied at the Denotame site in central Japan with pollen, plant macrofossils, and wood remains. From 6,250 cal bp, the middle phase of the early Jomon period, to 3,750 cal bp, the late Jomon period, there were deciduous forests dominated by Quercus on the higher land between the river valleys. In the lower land in the valleys or at their edges Alnus japonica grew at 6,250–5,900 cal bp, Juglans mandshurica at 6,100–3,750 cal bp, and Aesculus turbinata at 4,500–3,750 cal bp. While maintaining their settlements and making pottery from 5,300 to 3,600 cal bp, Jomon people managed Castanea crenata and Toxicodendron vernicifluum and used their timber and other resources and the nuts of Juglans through these periods and of Aesculus in later periods. Abundant occurrences of other plants from archaeological remains indicated the use of plants with edible fruits such as Morus, Quercus, Phellodendron amurense, Actinidia, Vitis, Rubus, and Broussonetia, and those with other uses such as Styrax, Sapindus mukorossi, and Sambucus racemosa. In contrast to many instances of social disturbance through the 4.2 ka event on the Asian continent, the event did not affect the life of the Jomon hunter–gatherers at Denotame. The stable temperature of the warm Kuroshio current during this period probably supported an unchanged environment and the undisturbed life of the Jomon people in central Japan.

Here, we present a comparative analysis of micro- and macrobotanical remains deposition in the small, shallow lake Lavagnone, which hosted a long-lasting Bronze Age pile dwelling in the southern Alpine foothills. We obtained a narrative of the vegetation history and a framework for plant depositional processes by compositional changes of micro/macro assemblages, co-registered off-shore, near to a lake dwelling site, naturally accumulated in a stable water column reached by domestic dumps. Data analysis has been supported by ecological grouping and multivariate ordination. The record spans the time of pristine forest surrounding the lake prior to the pile dwelling foundation (5530–2080 cal bc), a dramatic biodiversity reversal at the settlement foundation, and the subsequent development of farming and animal husbandry, recorded by an expansion of dry arable fields and pasture vegetation (2080–1470 cal bc). This long-term trend is likely the product of decreased soil water balance due to erosion of alfisol argillic horizons by overgrazing and hillslope ploughing. The near-site dynamic of plant deposition during the settlement phase consists of several episodes of dumping plant debris and faeces from dwelling in alternating layers with still natural, aquatic assemblages. Dump microfossils are predominantly represented by pollen and domestic charcoal, while macrofossils (seeds/fruits and macrocharcoal) mainly consist of food refuse, crop processing by-products, kitchen waste, cleaning remains of fireplaces, decayed faeces, etc. thrown directly into the water from the stilt houses and dispersed on the bottom of the lake.

Abstract This study aims to improve the understanding of climatic fluctuations in the southern Basin of Mexico (BM) during the Archaic (11,500–4,000 cal bp) and Formative (4,000–2,000 cal bp) archaeological periods, when early sedentary settlements at the Zohapilco and Atlapulco sites developed from ∼8,000–7,500 cal bp. This study is based on the analysis of diatoms, pollen, microalgae, charcoal, magnetic susceptibility, geochemistry (organic carbon and titanium) and micromorphology in sediments from a section in a 5 m deep trench at Tulyehualco in the southern BM, close to the Zohapilco and Atlapulco archaeological sites. The chronology is based on five radiocarbon dates and on the correlation with two dated tephra layers. Abundant diatoms and microalgae attest for a period of high lake levels during the deglaciation (17,000–11,000 cal bp), followed by lowering lake levels during the Greenlandian (11,000–8,200 cal bp) when summer insolation peaked, and more oxidative subaerial conditions likely caused poor pollen preservation. Micromorphological analysis showed soil development processes and poor diatom and pollen preservation that confirmed subaerial (dry land) conditions during the 8,200 cal bp cold event. Zohapilco and Atlapulco were first occupied during this period of environmental difficulty. Better diatom and pollen preservation suggest a return to wetter conditions at ~ 7,500–6,500 cal bp, but unusually high charcoal concentrations could reflect human impact in the landscape since the mid Archaic. The diatom record showed that the late Formative (2,000 cal bp, 50 bc) abandonment of sites in the BM was associated with a new reduction in lake levels and a sedimentation hiatus.

The use of relative pollen productivity (RPP) values is an effective approach for calibrating the relationships between pollen and vegetation, and they are key parameters for quantitative vegetation reconstruction based on the REVEALS method (regional estimates of vegetation abundance from large sites). In this study we used vegetation surveys and surface soil pollen data from 22 sampling points in the Hoh Xil region on the Qinghai-Tibet Plateau to estimate the RPP values of six pollen types, Cyperaceae, Aster-type, Saussurea-type, Potentilla, Artemisia and Caryophyllaceae, using different sub-models (SM) of the extended R-value (ERV) model. The results indicated that SM 2 is more suitable for the estimation of pollen production in this area compared to SMs 1 and 3. Using two weighting methods, Prentice and 1/d (inverse distance), the RPP results with Potentilla as the reference taxon show minimal differences between the methods. In descending order of RPP values, the pollen productivity compared with Potentilla using the Prentice weighting method are: Cyperaceae (12.31 ± 2.15), Artemisia (11.16 ± 1.75), Aster-type (1.78 ± 0.32), Caryophyllaceae (1.43 ± 0.06) and Saussurea-type (0.31 ± 0.06); while for the inverse distance weighting method they are Cyperaceae (13.91 ± 1.91), Artemisia (8.26 ± 1.92), Aster-type (1.56 ± 0.27), Caryophyllaceae (1.39 ± 0.08) and Saussurea-type (0.26 ± 0.07). Furthermore, modern vegetation reconstructions based on recent pollen from lake surfaces using the REVEALS model demonstrated that both sets of RPP reconstructions more closely approximate to the actual vegetation cover than the lake pollen percentages. Our findings provide insights for reconstructing past changes in vegetation cover and for predicting future vegetation changes in the Hoh Xil region.

Fundamental to understanding plant species distributions are the roles of natural and anthropogenic mechanisms of dispersal. Recent attention has focused on mechanisms of long-distance dispersal, and some research has examined whether past Indigenous peoples dispersed preferred plant species long distances in North America. Assessing dispersal mechanisms is crucial to understanding a plant’s capacity for range shifts under future climate change. This study investigated the northern distribution of pawpaw (Asimina triloba [L.] Dunal), a species of ecological, horticultural, and cultural value for which researchers have debated the relative role of different dispersal mechanisms including past Indigenous facilitation. Focusing on western New York State (NYS), this study employed interdisciplinary analysis to infer the possibility of human-facilitated dispersal of the species, including by analysing archaeological site data and historical records. Results suggested that pawpaw distribution is primarily driven by natural dispersal (i.e. hydrochory, endozoochory), though some populations may have originated from Indigenous or Euro-American planting. Given the buoyant characteristics of A. triloba fruit and seeds, Great Lakes (i.e. Lake Erie and Lake Ontario) currents were and are capable of facilitating long-distance dispersal into western NYS. This study also suggested that A. triloba is less rare in the study area than once thought (n = 70 populations historically and/or presently) and is within its climatic limits. This study broadly provided insight into the relative roles of natural and human-aided dispersal for a noteworthy tree species of eastern North America.

Abstract This study examines historical forest compositional changes in the Aggtelek Karst region, Hungary, focusing on the relationship between medieval and modern age charcoal burning sites (32 kilns) and the current vegetation. Our aim was to determine woodland composition during the intensive charcoal burning period using wood charcoal analysis and compare it with the present canopy composition to understand Fagus sylvatica (European beech) population dynamics at the margin of its range. Heat map visualization, cluster analysis and Procrustes analyses were used for comparison. The results show European beech as dominant taxon in charcoal spectra in some places, while Quercus, possibly Quercus petraea (sessile oak), and Carpinus betulus (European hornbeam) dominated in others. The findings suggest that beech had varying abundance in the potential beech habitats during the medieval and modern age coppice phases. We found multidirectional changes in canopy composition. Carpinus betulus and Q. petraea dominated the current stands in most cases with F. sylvatica being subordinate. These results suggest that historical forest use and management practices took place in already mixed canopy forests, where Fagus dominance was confined to a few stands only. We demonstrate that the forest stands plausibly represent different stages of secondary succession after last coppice management, leading to varying Carpinus abundance. We discuss the possible role of climate change (summer heat waves, increasing mean annual temperature) and conclude that F. sylvatica and Q. petraea compete with each other in the study region, confirming a transitional zone between the classical Fagus and Quercus climate.

To understand human practices and landscape evolution it is crucial to be able to trace evidence of past fires, notably in tropical environments. In such anthromes, phytoliths are generally well preserved and provide local signals on the environment. However, the different approaches to identifying burnt or heated phytoliths have proved inadequate. The recent investigation of auto-fluorescent phytoliths as proxy indicators of fire opens up new possibilities, however such studies have so far been limited to European temperate regions. The present contribution further explores the potential of this technique, attempting to reconstruct fire histories in tropical and subtropical latitudes. Therefore, we investigated various modern and ancient contexts in Guatemala, Senegal and the Canary Islands using descriptive and quantitative approaches to fluorescence. This comparative process revealed a diversity of fluorescence responses depending on the ecosystems studied, with anthropized areas often producing more fluorescent phytoliths. These results were obtained despite the use of different extraction and mounting methods. In contrast, coloured phytoliths, often considered an indicator of environmental burning, proved not very informative in some of the samples. This study reinforces our conviction that the auto-fluorescence of phytoliths is a universal phenomenon and is useful as a new proxy for detecting ancient fire in tropical and subtropical archaeological and palaeoenvironmental deposits.

The Middle and Lower Yangtze valley is recognized as the earliest centre of rice agriculture. Rice cultivation, alongside the utilization of various starchy plants, has persisted over millennia since the early Neolithic. While previous discussions have extensively explored the use of nuts, tubers, and large-grain grasses, small-grain grasses have received relatively little attention. This study examines plant impressions found in pottery sherds dating to the early Shangshan period (ca. 12,711–8,538 cal bp) to shed light on the significance of barnyard grass (Echinochloa sp.) during this era. Using microCT technology, we obtained clear and detailed visualizations of plant remains from pottery sherds, enhancing the archaeobotanical assemblage in a context where macro plant remains were scarce. Our study provides compelling evidence of diversified cultivation practices in the Lower Yangtze valley during the early Neolithic period. Furthermore, it situates the origins of rice agriculture within the broader framework of wetland plant management.

AbstractThe Ural Mountains represent a distinctive bioecological and climatic boundary between Europe and Asia, simultaneously uniting them through cultural, ethnic, and economic ties throughout history. To investigate these complex human-environment interactions during the last ~ 10,000, we obtained a peat core Shabunichi-1 and analyzed it using AMS radiocarbon dating, loss-on-ignition, pollen, non-pollen palynomorphs, micro- and macrocharcoal analyses. Our palaeoecological study demonstrate that climate and frequent fires were the main drivers of ecosystem change until ~ 4,000 cal bp. Dry climate conditions between ~ 9,300 and 7,400 cal bp resulted in the dominance of pine-birch forest-steppe as well as frequent local fires. Subsequent climate humification led to the expansion of broad-leaved-dark coniferous forests and a change in the fire regime, reducing the frequency and/or severity of fire events between ~ 7,400 and 5,100 cal bp. The peak in climatic humidity was reached between 5,100 and 3,900 cal bp, which favored the development of spruce forests with a greater admixture of broad-leaved species. After ~ 4,000 cal bp, anthropogenic impacts began to shape the appearance of regional ecosystems culminating in the maximum landscape openness during the Bronze and Iron Ages. The activities of Bronze Age cultures and the emergence of metallurgy and pastoralism in the region led to the strong decline of spruce forests and the spread of secondary pine-birch formations and meadows. Human impact during the Iron Age and the emergence of agriculture in the region caused the largest local fires and the reduction of interfluvial forests. Despite humans becoming the primary driver of ecosystem change in the second half of the Middle and Late Holocene, climate continued to play a critical role in triggering cultural transformations and migration processes in the region.

AbstractCharred masses of nearly 100,000 Linum usitatissimum (flax) seeds were found in house remains from Tjudnäs on the Åland Islands, Finland, and radiocarbon dated to ad 880–1020. The flax seeds were large and discovered in lumps, which indicates that they had been pressed for their oil. The flax was accompanied by seeds of Cuscuta epilinum, Lolium remotum, Galium spurium and Camelina alyssum/sativa, which are specific weeds of flax fields that mimic it in the flax fields and during crop processing. Several of these species have now become extinct or rare after the introduction of more effective methods of weed control and less flax growing. This find demonstrates the antiquity of this obligate flax weed flora, which appears to have been introduced to Åland together with flax seeds intended for cultivation. Thousands of cereal grains discovered in Viking Age/early medieval (ad 750–1300) Kohagen show that a broad range of crops was grown, with high proportions of Triticum aestivum (naked wheat). Stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) ratios were done on the flax from Tjudnäs and other crops from Kohagen, all from samples dated ad 880–1020. The analyses showed high values of δ15N, which can be explained by considerable soil enrichment with manure, possibly also with maritime resources such as seaweed and fish. The δ13C values varied between crops, with those for flax being lower than for cereals and Pisum sativum (peas), which could reflect different environmental conditions or differences in plant physiology. The factors affecting δ15N and δ13C in flax are, however, poorly understood due to the lack of experimental studies.

AbstractThe Lusatian Urnfield culture (LUc, Lausitzer Kultur, kultura łużycka) was one of the most important cultural developments during the Late Bronze and Early Iron Age of central-eastern Europe, 1500–500 bc. In this article, we focus on the impact of the LUc and later cultures on the terrestrial and aquatic ecosystems at Bruszczewo on a microregional scale and within the broad context of analogous processes in central-eastern Europe. We did high resolution multi-proxy analyses of pollen, non-pollen palynomorphs (NPPs), diatoms and plant macrofossils, supplemented with a lithological and geochemical study of lake and peat deposits from near the archaeological site. The results revealed that between ca. 1020 and 920 bc, woodland clearance took place, possibly connected with farming. This probably contributed to the spread of the weeds Xanthium cf. strumarium and Convolvulus arvensis in the newly created disturbed habitats. Woodland clearance and other human activities contributed to better preservation of diatoms in the lake sediments, probably as a result of increased acidity in this environment. Diatoms, especially taxa preferring eutrophic waters and tolerant of large amounts of dissolved organic matter, were the most frequent at that time. Climate deterioration associated with the 2.8 ka event probably lessened human impact around the lake shore. The diatom records suggest prolonged ice cover on the lake and/or colder springs at that time. Another intensification of human impact occurred at ca. 530 bc and was probably related to activity by people of Pomeranian culture (kultura pomorska, Pommerellische Gesichtsurnenkultur). Later, from ca. 330 bc, arable farming activity declined and grazing was suggested by an abundance of coprophilous fungi spores which, however, should not be regarded as definitive indicators of pasture.

This study aims to use a rich, millennia-long anthracological dataset to observe the role of Olea europaea L. in the Early and Middle Holocene woody vegetation used by prehistoric groups in the circum-Aegean area. A synthesis of previous and new data obtained in the context of ERC project PlantCult, reflects variations in the distribution and abundance of Olea in the anthracological record and allows to assess the factors potentially responsible for these, i.e. changes in climatic conditions, subsistence strategies and/or socioeconomic organization. It is suggested by the present anthracological evidence that Olea would have been abundant in the vegetation cover in lowland areas of the Aegean during the Last Interglacial and would have probably survived the Pleniglacial in refugia of thermophilous taxa in southern locations and the islands. According to the anthracological data from Mesolithic and Early Neolithic sites on the islands and lowland coastal areas, Olea would have been sparse during the Early Holocene in the Aegean. The earliest presence of the taxon is recorded in 7th mill. bce contexts on the northern Aegean insular sites. In the following millennia, Olea remained infrequent in the study area even though sclerophyllous vegetation is well-documented. Anthracological evidence for high Olea values is testified in the second half of the 4th mill. bce in the central and southern Aegean. In the 3rd mill. bce, the simultaneous increase of Olea in the anthracological datasets from Early Bronze Age settlements on the islands and the circum-Aegean lowlands and the pollen record, suggests a shift of the economy to olive management and arboriculture, probably enhanced by sea-routes and exchange networks established already since the Final Neolithic.