Vegetation History and Archaeobotany

Correction to: Small things can make a big difference: a comparison of pollen and macrobotanical records of some food plants from medieval and post-medieval cesspits in the Netherlands and northern Belgium In the original publication, the caption of Fig. 1 is partly missing. It has been updated in this correction.

Small things can make a big difference: a comparison of pollen and macrobotanical records of some food plants from medieval and post-medieval cesspits in the Netherlands and northern Belgium Abstract This paper presents a review of records of pollen and botanical macroremains of a selection of food plants from late and post-medieval cesspits (12th century-19th century ad) in the Netherlands and northern Belgium. The presented data demonstrate that several food plants remain largely invisible in the macrobotanical records. These are all plants from which the flowers or flower buds (Borago officinalis, Capparis, Carthamus tinctorius, Crocus sativus, Syzygium aromaticum) or leaves (Anthriscus cerefolium, Spinacia oleracea) are eaten, or that are typical components of honey (Cistus). As a result, little is known about the import or local production and consumption of these food plants in these times. This review now shows that past use of some of these plants is reflected in the pollen assemblages of (post-) medieval cesspits. For the first time, a large archaeobotanical dataset is presented, including pollen, providing information on the past use of these plants between the 12th and 19th century ad in the Netherlands and Belgium.

Palynology of Iron Age and Gallo-Roman archaeological sediments from Beaurieux Les Grèves, Aisne, France Abstract Pollen and non-pollen palynomorph analyses conducted on archaeological sediments from ditches and pits are used to investigate land-use and vegetation history around the long-lived rural settlement of Beaurieux Les Grèves in the Aisne valley, Picardy, northern France. Samples were examined from successive phases spanning the 8th century bc to the 3rd century ad. Each phase showed evidence of agriculture and human impact on the environment. The earliest occupation was during the early Iron Age, and the area around the site was shown to have been almost completely deforested and mainly pasture. The later Iron Age supported mixed agriculture, probably with pasture around the settlement site and cereal fields further away. In Gallo-Roman times there was mixed farming with considerable cereal cultivation, although the area near the site was mainly pasture or abandoned land. Late Gallo-Roman times saw a reduction in agricultural activity and some regeneration of heath and scrub vegetation. Coprophilous fungal spores are conspicuous and indicate the importance of animal husbandry on and around the site. The data from Beaurieux Les Grèves augment earlier analyses from settlements and natural deposits in the Aisne valley in suggesting almost complete deforestation for agricultural land use within the valley bottom, although some woodland undoubtedly survived on the steeper valley sides and nearby plateaux. It agrees with the pollen evidence from the wider region of north-eastern France that shows clearance of Fagus-dominated woodland for mixed agriculture in late Iron Age and Gallo-Roman times, and increasingly for arable cultivation. This was responsible for effecting a transformation from a partly wooded to a mainly open landscape.

Distribution and vegetation representation of pollen assemblages from surface sediments of Nam Co, a large alpine lake in the central Tibetan Plateau Abstract Lacustrine fossil pollen records have been widely used to reconstruct palaeovegetation and palaeoclimate changes on the Tibetan Plateau (TP). However, little is known about the vegetation representation of modern lacustrine pollen assemblages there. This paper presents the results of modern pollen investigation on 63 surface sediments from the lake basin and 37 topsoil samples from the drainage area of a large lake, Nam Co, located in the central TP. It aims to assess quantitatively the influences on lacustrine pollen assemblages of the pollen sources and sedimentary processes, and to establish vegetation representations for modern lacustrine pollen assemblages. Modern pollen assemblages from topsoils of different vegetation had diagnostic features in terms of their composition and pollen percentage. The spatial variabilities and results of principal component analysis suggested that lacustrine pollen assemblages were influenced by both the regional/local source vegetation and sedimentary processes. The lacustrine pollen assemblages were mainly homogeneous due to in-lake sedimentary processes (mixing and redistribution). An accumulation zone for lacustrine pollen assemblages was found in the deep lake basin (depth > 60 m) due to sediment focusing. The results of boosted regression tree analysis further confirmed that source vegetation was the predominant factor (85.8%) responsible for the vegetation representation of lacustrine pollen assemblages, while sedimentary processes accounted for only 14.2%. The results of discriminant analysis indicated that most lacustrine pollen assemblages (90.5%) were representative for the regional vegetation of alpine steppe in the Nam Co catchment and central TP, while only 9.5% were representative for the local meadow vegetation. Therefore, it is recommended that lacustrine pollen assemblages from deep lake basin of accumulation zone in large lakes of the TP can be used to retrieve efficiently the signals from regional vegetation and climate changes.

The native status of Pinus pinaster on serpentine soils: charcoal analysis and palaeoenvironmental history in Sierra Bermeja (southern Iberian Peninsula, Spain) Abstract Pinus pinaster (maritime pine), a conifer native to the western Mediterranean, has a broad distribution, occupying a wide variety of habitats. On certain substrata such as ultramafic (ultrabasic) rock, the indigenous nature of this conifer has traditionally been questioned by the scientific community, which has regarded it as an introduction. In Sierra Bermeja, mountains forming the largest ultramafic outcrop in western Europe, the dominant woodland formations on serpentine soils are P. pinaster and Abies pinsapo. However the variable presence, albeit isolated, of various species of arboreal Quercus and the frequent forestry plantation of P. pinaster in recent centuries have led to broad-leaved woods being generally considered as the dominant natural communities in this mountain range, so marginalizing the role of these conifers. In an attempt to settle this scientific controversy, we have carried out soil charcoal analyses from seven localities in Sierra Bermeja. The palaeoecological data we have gathered show that P. pinaster has a natural status and has been present in this mountain range during a large part of the Holocene before the changes to its natural landscape by human activities. These results are of great importance for the management and conservation of rare serpentine ecosystems.

Complex responses of vegetation diversity to Holocene climate change in the eastern Tibetan Plateau Abstract Biodiversity has attracted much attention recently due to its important relationships with ecosystem function under various global warming scenarios. However, an understanding of biodiversity mechanisms requires study over long time scales. Three high-resolution pollen records of Zoige Basin in the eastern Tibetan Plateau are used to reconstruct changes in vegetation diversity during the Holocene, allowing the mechanisms that drove the dynamic to be quantitatively explored. Rarefaction and Hill's indices are used to estimate the diversity richness and evenness based on pollen data. The results show that changes in palynological richness can be divided into five stages: an abnormal change from 10,500 to 9,000 cal bp, an obvious increase from 9,000 to 6,500 cal bp, a decreasing trend from 6,500 to 4,000 cal bp, an increasing trend after 4,000 cal bp until 1,500 cal bp, and a highly fluctuating stage from 1,500 cal bp to the present. Palynological evenness is relatively stable throughout the Holocene except for during a briefly elevated period from ca. 4,000 to 1,500 cal bp. The result of Boosted Regression Tree analysis indicates that climate is the main driving factor and the effect of temperature is stronger than that of precipitation in the study region. However, during ca. 4,000–1,500 cal bp, palynological diversity is primarily affected by vegetation structure, as shown by an increase in palynological evenness, which can in turn be explained by the climate threshold theory. This research provides a long-term, high-resolution reconstruction of palynological diversity which could be used to infer vegetation diversity change in the ecologically sensitive Tibetan Plateau. The results imply that vegetation diversity in the region may increase under global warming if human impacts are not considered.

Methods of acquisition and use of firewood among hunter-gatherer groups in Patagonia (Argentina) during the Holocene Abstract The present article examines the ways of obtaining firewood and of using it by Patagonian hunter-gatherer groups and the relationship with their high mobility. With these goals, we have selected a range of archaeological sites in varied types of vegetation: forest, forest-steppe ecotone and steppe (according to pollen reconstructions and current records) in several different latitudes of Argentinean Patagonia: Paredón Lanfré (Río Negro province); Cerro Pintado (Chubut province); Cerro Casa de Piedra 7 and Orejas de Burro 1 (Santa Cruz province). The taxa, including Nothofagus pumilio, Austrocedrus chilensis, Ribes magellanicum, Embothrium coccineum and Fabiana imbricata, found among the scattered charcoal remains in the sediments of the four Patagonian sites, show how firewood was gathered in types of vegetation similar to the ones that nowadays surround the archaeological sites. The archaeobotanical results allow us to detect differences and similarities of the supply of wood and its relationship with human mobility, site functionality and the types of occupation.

Re-analysis of archaeobotanical remains from pre- and early agricultural sites provides no evidence for a narrowing of the wild plant food spectrum during the origins of agriculture in southwest Asia Abstract Archaeobotanical evidence from southwest Asia is often interpreted as showing that the spectrum of wild plant foods narrowed during the origins of agriculture, but it has long been acknowledged that the recognition of wild plants as foods is problematic. Here, we systematically combine compositional and contextual evidence to recognise the wild plants for which there is strong evidence of their deliberate collection as food at pre-agricultural and early agricultural sites across southwest Asia. Through sample-by-sample analysis of archaeobotanical remains, a robust link is established between the archaeological evidence and its interpretation in terms of food use, which permits a re-evaluation of the evidence for the exploitation of a broad spectrum of wild plant foods at pre-agricultural sites, and the extent to which this changed during the development of early agriculture. Our results show that relatively few of the wild taxa found at pre- and early agricultural sites can be confidently recognised as contributing to the human diet, and we found no evidence for a narrowing of the plant food spectrum during the adoption of agriculture. This has implications for how we understand the processes leading to the domestication of crops, and points towards a mutualistic relationship between people and plants as a driving force during the development of agriculture.

Comparison of a recent elm decline with the mid-Holocene Elm Decline Abstract The threat of devastating pathogens on a range of tree species has increased recently, which justifies the investigation of the temporal dynamics of tree declines caused by disease. The mid-Holocene Elm Decline was a widespread and synchronous event recorded in pollen diagrams across northwest Europe. The probable drivers of this event have been debated for over 80 years but the role of disease has gathered greatest support in recent decades. Here we report pollen data at sub-decadal resolution from a closely sampled sediment core from eastern Ireland covering the last 160 years. This provides data on the structure and dynamics of the surrounding woodland before, during and after the outbreak of Dutch elm disease in the 1970s. A decline in elm was also recorded in the 1940s associated with an earlier, less virulent, outbreak of elm disease. The elm population recovered from the 1940s outbreak after 20 years but did not recover from the 1970s pandemic. The pollen data also facilitate the comparison of this disease-mediated decline with the mid-Holocene Elm Decline; the impact of human disturbance and disease resulted in different woodland compositions and the adjustment of the woodland in response to these factors was rapid. The impact of Dutch elm disease on this elm 1970s population was very similar to that recorded in the mid-Holocene Elm Decline in Britain and Ireland.

20,000 years of interactions between climate, vegetation and land use in Northern Greece Abstract Detailed knowledge about the history of vegetation, fire and land use is scarce in Northern Greece. We analysed lake sediments from Limni Zazari (Northern Greece) to reconstruct the past local vegetation and fire history with a special focus on land use and its impacts on erosion and lake eutrophication. Our data suggest a rather dense steppic vegetation after ca 20,000 cal bp (18050 cal bc). Forest expansion with Pinus sylvestris and admixed Quercus pubescens started around 14,500 cal bp (12550 cal bc). After the onset of the Holocene, mixed deciduous sub-mediterranean oak forests expanded, accompanied by rapidly decreasing soil erosion rates and increasing aquatic biological productivity. Pollen of cereals and Plantago lanceolata suggests continuous farming activities in the region after 8,200 cal bp (6250 cal bc), in agreement with archaeological evidence. Fairly closed mixed pine-oak forests dominated the landscape until ca 3,500 cal bp (1550 cal bc) that were only temporarily reduced during the Neolithic around 7,100 and 6,500 cal bp (5150 and 4550 cal bc). Land cover changes and aquatic biogeochemistry were closely linked during this period. Forest phases corresponded to lake eutrophication and hypolimnetic anoxia (meromixis), whereas during periods of deforestation (e.g. around 8,200 cal bp/6250 cal bc) soil erosion rates and lake mixing increased, while aquatic productivity decreased. After 3,500 cal bp (1550 cal bc) humans disrupted forests and open land vegetation expanded (e.g. Artemisia, Rumex-type, Cichorioideae, Chenopodiaceae). With the onset of the Iron Age (ca. 3,050 cal bp/1100 cal bc) grassland communities expanded massively and pine-oak forests gradually declined. Anthropogenic pressure on forests increased even more during the past 500 years. Finally, forest recovery during the recent decades led to decreased erosion and increased lake productivity. We conclude that over the millennia, intense pastoral and arable activities shaped both aquatic and terrestrial environments, ultimately creating a humanized vegetation mosaic in which the original natural mixed deciduous oak forests only form relict stands. Future climate warming and decreasing anthropogenic pressure may release a rapid spread of mixed deciduous oak forests around Limni Zazari.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com