Pollen and non-pollen palynomorph evidence of medieval farming activities in southwestern Greenland

Radiocarbon dating, pollen and non-pollen palynomorph analyses from a lake core were used to establish the timing and effects of farming activities around Lake Igaliku, Eastern Settlement, Greenland. The absence of agro-pastoral impact before the medieval colonization by Europeans provides an opportunity to understand the development of farming activity in a pristine landscape. The results show that the first phase of clearance and grazing pressure, without the expansion of the Norse apophyte (native plant, in habitats created by humans) Rumex acetosa type, could have occurred in the 9–10th century a.d. The presence of Norse settlers and livestock is clearly recorded from the 11–12th century a.d. with increasing frequencies of the Norse apophytes Rumex acetosa type and Ranunculus acris type, and coprophilous fungi. This colonization phase is followed by a period of decreasing human impact at the beginning of the 14th century, with a decrease in weeds, apophytes and coprophilous fungi suggesting a reduced grazing pressure. The regrowth of Salix and Betula and the disappearance of anthropogenic indicators except Rumex acetosa type between the 15th and 18th century demonstrate the abandonment of the settlement, until the development of contemporary agriculture in the 20th century.     

Vegetation and fire history with their implication for climatic change and fire events since the last deglacial in the Aso Valley, central Kyushu, southwestern Japan: new pollen and charcoal data

To better understand the response of forest vegetation to climate and fire regimes with reference to human activities over the last deglacial period in the Aso Caldera, central Kyushu, southwestern Japan, a 33.9 m long sediment core was examined in order to reconstruct the vegetational and fire history using pollen and charcoal analyses. The results show that a cool temperate broad-leaved deciduous forest, dominated by Quercus (deciduous oaks) with Carpinus and Fagus, prevailed in the Aso Valley from ca. 14.6 ka cal. b.p., indicating warming since the last glacial period. The landscape was presumably covered by a mosaic of deciduous Quercus forests and terrestrial Artemisia communities. Around 12.8–11.7 ka cal. b.p., Quercus dominated the forest and fires occurred frequently. Co-expansion of distinctive Ulmus–Zelkova and Celtis–Aphananthe forests coupled with a progressive retreat of Quercus in the early Holocene could reflect a strengthening of the East Asian summer monsoon under mild and humid climate conditions. Around 8 ka cal. b.p., significant increases in Cyclobalanopsis (evergreen oaks), Castanopsis/Castanea and Podocarpus indicate a further warming, in particular an increased winter temperature. Warm temperate lucidophyllous forests, dominated by Cyclobalanopsis, flourished after 7.3 ka cal. b.p., probably corresponding to the “Holocene Climatic Optimum” interval. Progressive expansion of Quercus at the expense of Cyclobalanopsis began around 6.4 ka cal. b.p. and paralleled an increase in charcoal until ca. 4.8 ka cal. b.p.; this could be evidence of fire disturbance induced by the early-middle Jomon people. The disturbed evergreen forest experienced a temporary recovery but then opened again from 3.6 ka cal. b.p. due to extensive fire deforestation, as suggested by the high charcoal levels during this time. Human exploitation and buckwheat (Fagopyrum) agriculture may have contributed to the opening of the forest, which allowed secondary forests (primarily Pinus and Quercus) and herbaceous communities (mainly Poaceae) to spread. These results are discussed in comparison with other high-resolution pollen data from western Japan to better elucidate the vegetation and fire history over the last deglacial in the Aso Caldera.     

Land use history and resource utilisation from a.d. 400 to the present, at Chibuene, southern Mozambique

This paper discusses changing patterns of resource utilisation over time in the locality of Chibuene, Vilankulos, situated on the coastal plain of southern Mozambique. The macroscopic charcoal, bone and shell assemblages from archaeological excavations are presented and discussed against the off-site palaeoecological records from pollen, fungal spores and microscopic charcoal. The Chibuene landscape has experienced four phases of land use and resource utilisation that have interacted with changes in the environment. Phase 1 (a.d. 400–900), forest savanna mosaic, low intensity cattle herding and cultivation, trade of resources for domestic use. Phase 2 (a.d. 900–1400), forest savanna mosaic, high intensity/extensive cultivation and cattle herding. Phase 3 (a.d. 1400–1800), savanna woodland and progressive decrease in forests owing to droughts. Decline of agricultural activities and higher reliance on marine resources. Possible trade of resources with the interior. Phase 4 (a.d. 1800–1900), open savanna with few forest patches. Warfare and social unrest. Collapse of trade with the interior. Decline in marine resources and wildlife. Loss of cattle herds. Expansion of agriculture locally and introduction of New World crops and clearing of Brachystegia trees. The study shows the importance of combining different environmental resources for elucidating how land use and natural variability have changed over time.     

Neolithic human impact on the landscapes of North-East Hungary inferred from pollen and settlement records

In this article, we discuss the Neolithic and Early Copper Age (ECA) part of two pollen records from the Middle Tisza Floodplain in association with the local archaeological settlement record. We address the hypothesis of Willis and Bennett (2004) that there was little human impact by farmers on the environment of SE Europe until the Bronze Age. Contrary to this hypothesis, our results show that small-scale agriculture and woodland clearance is already attestable in the earliest Neolithic in Eastern Hungary, there are signs of expanding scale of mixed farming in the Middle Neolithic and strong evidence for extensive landscape alterations with enhanced pasturing and mixed farming in the Late Neolithic (LN) and ECA. The main vegetation exploitation techniques in the alluvial plain of Sarló-hát were selective tree felling (mainly Quercus), coppicing (mainly Corylus and Ulmus) and woodland clearance to establish grazing pastures and small-scale crop farming. Comparison with other well-dated pollen diagrams from Eastern Hungary suggested that, in the Early and Middle Neolithic (8000–7000?cal.?b.p.), Corylus and Ulmus coppicing were probably frequent, while pastoral activities and associated woodland clearance is distinguished in the LN (7000–6500?cal.?b.p.). Our data also suggested a shift to moister summer conditions in the alluvium during the ECA, which may have contributed to a trend towards settlement dispersion and increased reliance on animal husbandry in the NE Hungarian Plain.     

Vegetation change during the Bronze Age studied in a multi-proxy approach: use of wood linked to charcoal analysis

During recent archaeological excavations in the alpine valley of Montafon, western Austria, a Bronze and early Iron Age settlement cluster located at about 1,000 m a.s.l. was excavated. The human impact on the woodland resulting from these prehistoric settlement activities has been evaluated by the analysis of charred plant macro remains from cultural layers from a hilltop settlement site and two other close-by settlements, all of them encompassing the Early and Middle Bronze Age (19th to 15th century cal. b.c.) and early Iron Age (6th/5th century cal. b.c.). Charred seeds and fruits have provided information on the supply of foodstuff while charcoal (anthracological) analyses of firewood have revealed the use of wood and consequently the changes in local woods. The latter analyses suggest that the spruce-fir woodland (Piceeto-Abietetum) was gradually cleared from the Early Bronze Age. During the Middle Bronze Age large amounts of Pinus sylvestris (pine), Betula (birch), Corylus avellana (hazel) and Sorbus (rowan) with some Picea abies (spruce) characterized the woods, and early succession stages indicate clearings. These anthracological studies are corroborated by pollen studies disclosing clearings in the woods since the Early Bronze Age, which gradually expanded during the Middle Bronze Age. Furthermore, several charcoals from a Middle Bronze Age hearth seem to be of the same age, and the pattern of their annual growth-rings suggests the pollarding of broadleaved trees.     

Vegetation history of mid- to western Ireland in the 2nd millennium a.d.; fresh evidence from tephra-dated palynological investigations

The historic Icelandic tephra layers, from Hekla in a.d. 1104 and Öræfajökull in a.d. 1362 that have been found in four peat profiles obtained from lowland and upland mid to western Irish bogs, provide the dating for high-resolution palynological investigations of regional land use over the last thousand years. Marginal agriculture is investigated through the study of an upland blanket peat and a lowland Atlantic blanket peat. At the lowland site, the landscape has been altered, primarily by removal of hazel scrub, while in the uplands, there has been little scrub woodland throughout the last millennium. Pastoral agriculture has a long, unbroken history at both sites, with a short period of arable agriculture, dated to the early 19th century, detected in the uplands. At the two lowland sites, changes in land use associated with medieval monastic and secular activity were similar but not synchronous. The a.d. 1362 tephra in one lowland profile provides high-resolution dating of the palynological evidence for agricultural collapse in the aftermath of the Black Death. The palynological evidence of late medieval woodland clearance is contrasted with the written record. The effects of 19th century population expansion on land use are considered. A synthesis of regional land use in Ireland during the last thousand years is presented.     

Parasites of bark beetles [Col.: Scolytidae] on pine and cypress in Israel

Ten species of hymenopterous parasites were reared from logs of pine and cypress, naturally infested with 5 species of bark beetles,viz., Orthotomicus erosus Woll.,Pityogenes calcaratus Eichh., andTomicus destruens Woll. — on pine;Phloeosinus armatus Reitt. andP. aubei Perris — on cypress, in Israel. The parasites were:Dendrosoter chaenopachoides Rusch,D. hartigii (Ratz.),D. middendorfi (Ratz.),D. protuberans Nees (Braconidae), Eurytoma morio Boheman (Eurytomidae), Cerocephala eccoptogastri Masi,Heydenia pretiosa F?rster,Metacolus unifasciatus F?rster,Rhaphitelus maculatus Walker andRoptrocerus xylophagorum (Ratz.) (Pteromalidae). The most common wereM. unifasciatus on pine and cypress,D. chaenopachoides andR. xylophagorum on pine, andD. protuberans on cypress, occurring in samples collected during most seasons. Less common wasE. morio, which was reared from both conifers.D. middendorfi was found on pine, and only during winter. The other species were found only occasionally.     

Woodland disturbance and possible land-use regimes during the Late Mesolithic in the English uplands: pollen, charcoal and non-pollen palynomorph evidence from Bluewath Beck, North York Moors, UK

Pollen, micro-charcoal and non-pollen palynomorph (NPP) data from the mid Holocene Ulmus decline and the preceding millennium have provided evidence of repeated fire disturbance of the upland woodland at Bluewath Beck Head, on the North York Moors in northeast England. Woodland disturbance coincides with the Ulmus decline, which at several similar upland sites in northern England is dated to ca. 4800 uncal b.p. (ca. 5550 cal b.p.), and so to the early Neolithic period. Two fire events occur within a cycle of disturbance and regeneration between about 6100 (ca. 6950 cal b.p.) and 5700 b.p. (ca. 6475 cal b.p.), placing them in the later stages of the Late Mesolithic hunter-gatherer occupation of the upland and near the start of the transition to early Neolithic agricultural economies. Increased Melampyrum and Corylus pollen percentages characterise the post-fire vegetation response. These disturbances probably resulted from human activity, suggesting that fire was an integral part of the Late Mesolithic ecology. The local origin of some NPPs greatly enhances the palaeoecological interpretation, showing variations in the hydrological responses to disturbance that are much less visible in the pollen record, and helping to distinguish between local and regional vegetation changes. Other NPPs indicate burning near to the site. A substantial peak in spores of the wood-rot fungus Kretzschmaria deusta across the Ulmus decline may indicate girdling and other woodland management techniques as part of Neolithic woodland farming.     

The Iron Age in the Mrągowo Lake District,Masuria, NE Poland: the Salęt settlement microregion as an example of long-lasting human impact on vegetation

Pollen, non-pollen palynomorphs, charcoal and geochemical analyses of sediments from Lake Sal?t (NE Poland) were used to reconstruct vegetation changes related to the activity of the West Balt tribes during the Iron Age, in the period between the second half of the 7th century bc and the beginning of the 10th century ad. We distinguished five phases of human impact on environment. Woodland clearing around the studied lake started at the end of the 7th century bc. The most characteristic feature of this area during the whole Iron Age was a very high representation of semi-natural Betula woodlands, which was probably linked to a shifting agriculture. This type of land use lasted for over 1,500 years, until the second half of the 9th century ad. The greatest reduction in Betula woodlands took place between cal. years 650 and 450 bc. Its regeneration took place after ca. ad 830 when human activity decreased.     

Contemporaneous Alnus decline and the beginning of Iron Age cultivation in pollen stratigraphies from southern Finland

Declines in Alnus coinciding with the first signs of Iron Age (a.d. 0–1150) human activities were found in the pollen stratigraphies of five small lakes in southern Finland. One lake did not show a clear minimum. Three of the lakes were investigated with close-interval analyses which showed that the Alnus minimum lasted for several centuries. The results were compared with 41 previously published pollen diagrams with evidence of Iron Age human activity from southern Finland. These diagrams were classified in three ways: (1) showing no Alnus minimum; (2) cases where a minimum was unclear; (3) showing a clear minimum in Alnus. The different types were found randomly scattered around southern Finland suggesting that Alnus minima were a local phenomenon. In most cases the Alnus minimum took place between ca. a.d. 600 and ca. a.d. 1000, a.d. 1300 being the latest date for the end of the minimum. The results do not suggest a pathogen outbreak over the entire area. The beginning of the minimum clearly coincides with the onset of Iron Age anthropogenic activities suggesting that these were the probable cause. Pollen analysis provides little information as to why trees were felled thus archaeological evidence is needed. However, the Alnus decline may prove a new and useful indicator of the onset of Iron Age anthropogenic activity in pollen diagrams.     

The environmental and cultural contexts of the late Iron Age and medieval settlement in the Mazurian Lake District,NE Poland: combined palaeobotanical and archaeological data

Pollen analysis of sediments from three lakes and analysis of plant macroremains including charcoal from archaeological sites in the Mazurian Lake District provide new data for the reconstruction of vegetation changes related to human activity between the 1st and 13th century ad. At that time settlements of the Bogaczewo culture (from the turn of the 1st century ad to the first part of the 5th century ad), the Olsztyn Group (second part of the 5th century ad to the 7th or beginning of the 8th century ad), and the Prussian Galinditae tribes (8th/9th–13th century ad) developed. The most intensive woodland clearing occurred between the 1st and 6th/7th century ad. Presence of Cerealia-type, Secale cereale and Cannabis-type pollen, as well as macroremains of Hordeum vulgare, S. cereale, Triticum spelta, T. cf. monococcum, T. cf. dicoccum, Avena sp. and Panicum miliaceum documented local agriculture. High Betula representation synchronous with microcharcoal occurrence suggests shifting agriculture. After forest regeneration between c. ad 650 and 1100, the area was strongly deforested due to the early medieval occupation by Prussian tribes. The archaeobotanical examination of samples taken in a cemetery and a large settlement of the Roman Iron Age revealed strong differences in the taxonomic composition of the fossil plant remains. An absolute dominance of birch charcoal in the samples from the cemetery indicates its selective use for funeral pyre construction. There is a difference between cereals found in both contexts: numerous grains of Triticum have been found in the cemetery, while in the settlement crops were represented mostly by Secale and Hordeum. Grass tubers, belonging probably to Phleum pratense, are among the particularly interesting plant remains found in the cemetery.     

Study on allergenicity of Thuja orientalis pollen grains in rat

Cupressaceae pollen allergy is an important cause of pollen allergy throughout the world. Prevalence of allergy to Cupressaceae pollen has increased significantly during the winter over the past 3 decades because of extensive planting of cypress trees for different purposes. Thuja orientalis (Cupressaceae) is a naturally grown plant in Iran and is widely cultivated as a common ornamental plant in this country and other ones. Allergenicity of its pollen has been established, but to this day no allergenic component has been detected. The aim of this research is to study allergenicity and evaluate the immunoglobulin E reactivity to T. orientalis pollen extracts. Pollen grains were directly collected from mature male cones of trees. Pollen proteins were extracted and were analyzed by SDS-PAGE. Total protein content of pollen extracts was measured by Bradford assay. Immunoblotting using the serum of sensitized rats showed a single immunogenic band at about 44KD in pollen extracts. Result of this research proved that pollen grains of T. orientalis are allergenic.     

d-Amino Acid-Induced Expression of d-Amino Acid Oxidase in the Yeast Schizosaccharomyces pombe

We investigated d-amino acid oxidase (DAO) induction in the popular model yeast Schizosaccharomyces pombe. The product of the putative DAO gene of the yeast expressed in E.?coli displayed oxidase activity to neutral and basic d-amino acids, but not to an l-amino acid or acidic d-amino acids, showing that the putative DAO gene encodes catalytically active DAO. DAO activity was weakly detected in yeast cells grown on a culture medium without d-amino acid, and was approximately doubled by adding d-alanine. The elimination of ammonium chloride from culture medium induced activity by up to eight-fold. l-Alanine also induced the activity, but only by about half of that induced by d-alanine. The induction by d-alanine reached a maximum level at 2?h cultivation; it remained roughly constant until cell growth reached a stationary phase. The best inducer was d-alanine, followed by d-proline and then d-serine. Not effective were N-carbamoyl-d,l-alanine (a better inducer of DAO than d-alanine in the yeast Trigonopsis variabilis), and both basic and acidic d-amino acids. These results showed that S. pombe DAO could be a suitable model for analyzing the regulation of DAO expression in eukaryotic organisms.     

Old World and New World Cupressus pollen: morphological and cytological remarks

The aim of this work was to collect new information about pollen morphology and pollen wall structure comparing Cupressus species from the Old World and New World. Cupressus is a nonmonophyletic genus that includes species that appear to be divided into Old World and New World clades. Observations in this study on cypress pollen indicate that grain size and composition of intine β-glucans are different between the considered Old World and New World species. Different from all the other American cypress species, pollen of C. macrocarpa reacted to dying in a similar manner to Old World species. Rehydrated pollen grains collected from 20 Asian, Afro-Mediterranean and American cypress species were measured under a light microscope. The size of the pollen grains and the percentage of intine in relation to the pollen grain diameter were significantly different between Old World and New World species. Pollen wall composition was tested after addition of different dyes to the hydration solution, and subsequent observations were carried out by light and fluorescence microscopy. Lugol and calcofluor staining showed differences in composition of the middle and inner intine layers between New World and Old World species.     

Early–Middle Holocene vegetation history, climate change and human activities at Lago Riane (Ligurian Apennines, NW Italy)

The radiocarbon-dated palaeoecological study of Lago Riane (Ligurian Apennines, NW Italy) presented here forms part of a wider investigation into the relationships between Holocene vegetation succession, climate change and human activities in the northern Apennines. The record of vegetation history from Lago Riane indicates that, since the end of the last glaciation, climate change and prehistoric human activities, combined with several local factors, have strongly influenced the pattern and timing of natural vegetation succession. The pollen record indicates an important change in vegetation cover at Lago Riane at ~8500–8200 cal. years b.p., coincident with a well-known period of rapid climate change. At ~6100 cal. years b.p., Fagus woodland colonised Lago Riane during a period of climate change and expansion of Late Neolithic human activities in the upland zone of Liguria. A marked decline in Abies woodland, and the expansion of Fagus woodland, at ~4700 cal. years b.p., coincided with further archaeological evidence for pastoralism in the mountains of Liguria during the Copper Age. At ~3900–3600 cal. years b.p. (Early to Middle Bronze Age transition), a temporary expansion of woodland at Lago Riane has been provisionally attributed to a decline in human pressure on the environment during a period of short-term climate change.     

POLLEN MORPHOLOGY AND PLANT TAXONOMY OF WHITE OAKS IN EASTERN NORTH AMERICA

An evaluation of possible approaches to fossil oak pollen identification utilized scanning electron microscopy to examine exine-surface features of 171 collections, representing 16 Quercus subgenus Lepidobalanus species and varieties of eastern North America. Twenty qualitative pollen morphological characters were defined and tabulated for each of 217 pollen grains. The data were subjected to cluster analysis and cluster diagrams were compared with published white oak taxonomy. Pollen morphology and plant taxonomy compared well in series of the subgenus Lepidobalanus due primarily to consistency of character presence and absence within species and varieties. Pollen morphology of white oaks appears to reflect plant systematics above the species level. Use of routine SEM analysis to identify series of white oaks among fossil pollen grains likely will yield valid results.     

18,000 years of grassland evolution in the summer rainfall region of South Africa: evidence from Mahwaqa Mountain,KwaZulu-Natal

A palynological and sedimentological record from the Mahwaqa Mountain in KwaZulu-Natal, South Africa, provides evidence of the vegetation dynamics in this part of the Grassland Biome during the last c. 18,000 years. The wetland is located at 1,850 m on an isolated outlier of the Ukhahlamba–Drakensberg Mountain range on an ecotone along a climatic gradient. The vegetation responded to humidity and temperature changes during the late Pleistocene and Holocene. The period c. 18,000–13,500 cal. bp is characterized by high Ericaceae and Restionaceae percentages and decreasing values of charred particles, indicating cool conditions. Around 13,500–8,500 cal. bp, Ericaceae were gradually replaced by Poaceae, signaling climate warming. Growing environmental wetness during the same time period is inferred from Phragmites-type and Cliffortia pollen percentages. Since c. 8,500 cal. bp, Cliffortia, Restionaceae, and Phragmites-type percentages have maintained low levels. Ericaceae were almost completely replaced by grasses and Asteraceae by c. 7,500 cal. bp. All indications are that warm and fluctuating moisture conditions followed until 4,600 cal. bp but they became driest between c. 4,600 and 3,500 cal. bp, when high Asteraceae, Pentzia-type and Scabiosa percentages were prominent. From c. 3,500–800 cal. bp, the increase of sedges, Aponogeton and grass pollen (including Phragmites-type) at the expense of Asteraceae pollen suggests the return of slightly more humid conditions. Since c. 1,000 cal. bp an increase of water demanding Podocarpus and Cliffortia occurred. Pine pollen indicates the recent introduction of alien plants in the 19th and 20th centuries.     

Metabolic engineering of Escherichia coli for biosynthesis of d-galactonate

d-galactose is an attractive substrate for bioconversion. Herein, Escherichia coli was metabolically engineered to convert d-galactose into d-galactonate, a valuable compound in the polymer and cosmetic industries. d-galactonate productions by engineered E. coli strains were observed in shake flask cultivations containing 2 g L^?1 d-galactose. Engineered E. coli expressing gld coding for galactose dehydrogenase from Pseudomonas syringae was able to produce 0.17 g L^?1 d-galactonate. Inherent metabolic pathways for assimilating both d-galactose and d-galactonate were blocked to enhance the production of d-galactonate. This approach finally led to a 7.3-fold increase with d-galactonate concentration of 1.24 g L^?1 and yield of 62.0 %. Batch fermentation in 20 g L^?1 d-galactose of E. coli ?galK?dgoK mutant expressing the gld resulted in 17.6 g L^?1 of d-galactonate accumulation and highest yield of 88.1 %. Metabolic engineering strategy developed in this study could be useful for industrial production of d-galactonate.     

Postglacial history of vegetation,human activity and lake-level changes at Jezioro Linówek in northeast Poland,based on multi-proxy data

We present the postglacial history of vegetation, human activities and changes in lake level in the context of climate change in northeast Poland from ~14,000 cal. b.p. to the present day. The palaeoecological reconstruction is based on the results of high-resolution plant macrofossil analyses as well as records from pollen, Cladocera and radiocarbon dating. Climate fluctuations and human activity have caused many changes in vegetation development in Jezioro Linówek and in the vicinity of this lake. The Early Holocene warming that occurred at ~9500 b.c. caused an increase in Betula and the colonisation of Linówek by Potamogeton lucens, Nymphaea alba and Chara sp. At ~2300 b.c., climate cooling was accompanied by the spread of Picea abies and the appearance of Potamogeton alpinus and Nuphar pumila in the lake. The first traces of farming in the form of Cerealia pollen have been dated back to ~2100 b.c. The cultivation of Triticum began at ~250 b.c., Secale at ~a.d. 550, and Fagopyrum at ~a.d. 1720. The rapid increase in human activity at ~a.d. 1700 and the simultaneous loss of woodland is associated with the establishment of villages in the area and is expressed by the decline of tree curves. In Linówek, which was formed ~14,000 cal. b.p., three periods of high water level occurred (12000–9400, 7000–4000 and 1450 b.c.–a.d. 650), and two periods of low water level (9400–7100 and 3700–1700 b.c.). The changes of water level correspond well with other sites in central and northern Europe.