Pollen Composition Research Articles

Late-Holocene floodplain development, land-use, and hydroclimate–flood relationships on the lower Ohio River, US

Floodplain development, land-use, and flooding on the lower Ohio River are investigated with a 3100-year-long sediment archive from Avery Lake, a swale lake on the Black Bottom floodplain in southern Illinois, US. In all, 12 radiocarbon dates show that Avery Lake formed at 1130 BCE (3100 cal. yr BP), almost 3000 years later than previously thought, indicating that the Black Bottom floodplain is younger and more dynamic than previously estimated. Three subsequent periods of extensive land clearance were identified by changes in pollen composition, corresponding to Native American occupations before 1500 CE and the current Euro-American occupation beginning in the 18th century. Sedimentation rates prior to 1820 CE changed independently of land clearance events, suggesting natural as opposed to land-use controls. Comparison with high-resolution paleoclimate data from Martin Lake, IN, indicates that lower Ohio River flooding was frequent when cold-season precipitation originating from the Pacific/Arctic predominated when atmospheric circulation resembled positive Pacific North American (PNA) conditions and the Pacific Decadal Oscillation (PDO) was in a positive mean state (1130 BCE to 350 CE and 1150–1820 CE). Conversely, Ohio River flooding was less frequent when warm-season precipitation from the Gulf of Mexico prevailed during negative PDO- and PNA-like mean states (350 and 1150 CE). This flood dynamic appears to have been fundamentally altered after 1820 CE. We suggest that extensive land clearance in the Ohio River watershed increased runoff and landscape erosion by reducing interception, infiltration, and evapotranspiration, thereby increasing flooding despite a shift to negative PDO- and PNA-like mean states. Predicted increases in average precipitation and extreme rainfall events across the mid-continental US are likely to perpetuate current trends toward more frequent flood events, because anthropogenic modifications have made the landscape less resilient to changing hydroclimatic conditions.

Foraging behaviour of the stingless bee Melipona orbignyi (Hymenoptera: Apidae: Meliponini) in a dry forest assessed by multivariate analysis from palynological data

Pollen analysis was applied to study the botanical composition of honey and pollen stored by Melipona orbignyi in its southernmost distributional range. Many studies have revealed that robust buzzing bees of this genus are associated with diverse plant families, some of which are different to those exploited by the remaining genera of Meliponini. Cluster analysis was performed to assess similarity in botanical composition between pot-pollen and pot-honey provisions from different colonies. The results indicated that each colony was capable to access to different plant species for obtaining nectar and pollen, a fact observed when discarding the contaminated honey samples. As honey samples were not clustered together with other ones but with pollen samples indicating a similar botanical composition, it could be assumed that a same plant species provided nectar and pollen to bees. Resource partitioning was not clearly observed among a subset of late spring colonies, as two families of high richness of species and abundant in this dry forest (the mimosoid clade in Fabaceae and Capparaceae) were foraged. A higher number of synchronously sampled colonies would be necessary to detect this ecological aspect. The botanical composition of samples of M. orbignyi was governed by both random factors such as local and temporary flower availability plus preferences for particular plant species such as those from Solanaceae and Ximeniaceae. The Capparaceae and Ximeniaceae are here reported for the first time as intensively foraged pollen resources by the genus Melipona.

The difference in pollen harvest between Apis mellifera and Apis cerana in a Tibetan alpine meadow

To explore the difference in pollen harvest between the western honey bee Apis mellifera and a native eastern honey bee A. cerana in the Zoige alpine meadows in the northeastern part of the Qinghai-Tibetan Plateau, we investigated species diversity of the harvested pollen and the amount of harvested pollen per bee for both species, and calculated the niche overlap (in terms of similarity in harvested pollen) between the two bee species during the flowering season from June to August 2016. Results showed that the species diversity of the harvested pollen was indistinguishable between the two bee species. Nevertheless, A. mellifera carried more (although not significant) pollens per bee than A. cerana. Moreover, pollen composition differed between the two bee species: A. mellifera mainly foraged on Anemone rivularis, Saussurea nigrescens and Anemone trullifolia, while A. cerana foraged on Anemone rivularis, Stellera chamaejasme, and Pedicularis longiflora. Consistently, the niche overlap between the two honeybee species was particularly small in several observations. Our results indicate a niche separation in pollen resource between the two honeybee species in a Tibetan alpine meadow.

Significance of pollen assemblages for the vegetationcomposition of alpine shrub meadow in theQinghai-Tibetan Plateau, China

The Qinghai-Tibetan Plateau is a fragile, globally significant ecosystem which responds sensitively to global climate change and regional human activity. Modern observations show that the ecological environment of the Qinghai-Tibetan Plateau has changed substantially, with obvious regional differences in vegetation composition, since the 1980s. Studying the history of vegetation succession and changes in the spatial distribution of vegetation on the Qinghai-Tibetan Plateau can provide a scientific basis for accurate assessment and prediction of future changes. For this purpose, we selected Zeku Basin, in the northeastern Qinghai-Tibetan Plateau. The study area is open and flat and it belongs to the alpine and semi-humid climate zone with distinct seasonality. The annual average temperature ranges from −3−3°C, and the annual precipitation ranges from 400−700 mm and is concentrated during June-September. The regional vegetation in Zeku Basin includes alpine meadow and alpine shrub, which is mainly composed of herbs and shrubs tolerant of cold and humid conditions. The alpine meadow is dominated by Kobresia and Carex , accompanied by Compositae, Ranunculaceae, Poaceae and Potentilla , which are mainly distributed in basin areas and on the sunlit slopes of the mountains. The alpine shrubs are dominated by Potentilla fruticosa , with occasional Hippophae and Spiraea alpina , mostly distributed on the shaded slopes of the mountains. The extent of the study area was determined according to the degree of vegetation regionalization with reference to Google satellite imagery of Qinghai Province. 31 representative sites were selected within the study area, using the random layout method. At each site surface moss samples were collected and a vegetation inventory conducted. We analyzed the pollen composition of the surface samples and determined the characteristics of the pollen assemblages and the pollen source area in alpine shrub meadow. The principal results are as follows: (1) The pollen assemblages are dominated by Cyperaceae (29.75%), Aster (21.86%), Ranunculaceae (16.99%), Rosaceae (7.84%) and Poaceae (5.1%), which mainly originate from the vegetation within 40 km of the sites (the proportion of total pollen loading reached was 83%). There is the minor representation of the pollen of arboreal plants, such as Betula , Pinus and Picea , which was wind-transported over long distances. The vegetation composition varied substantially between different sites within distances of 0–100 m of each site, resulting in a poor relationship with the pollen assemblages. However, the pollen assemblages and the vegetation composition were more similar over the distance of 0–3 km from each site, suggesting that the regionally-homogenized vegetation has a better relationship with the pollen assemblages. (2) We suggest that the surface pollen assemblages from lakes in the Qinghai-Tibetan Plateau may be greatly affected by extra-regional pollen or intrazonal vegetation in the shrub meadow. High percentages of Artemisia and Chenopodiaceae in pollen assemblages do not reflect the coverage of these taxa in the corresponding regional vegetation. Therefore, within shrub meadow environments of the Qinghai-Tibetan Plateau, these taxa should be excluded from lake-sediment-based pollen studies of regional vegetation succession and climate change.

Differentiation of oak honeydew and chestnut honeys from the same geographical origin using chemometric methods

Oak honeydew and chestnut honeys often share the same production area in Atlantic landscapes. Consequently these honeys have common physicochemical properties and pollen composition, making their differentiation by routine methods, a difficult task. The increase in the demands of consumers for clear honey labelling, identifying floral make-ups and the substantial health properties of both honey types, make it necessary to improve methods to differentiate the honeys. Statistical multivariate techniques were used to study the differences in the physicochemical composition and pollen spectra between chestnut honey and oak honeydew honey. Palynological analysis, moisture, pH, electrical conductivity, hydroxymethylfurfural, diastase number, colour, phenolic content, minerals and sugars were used for this purpose. The variables that had more weight in the differentiation by principal component analysis were Castanea, Cytisus type, CIELab coordinates (a* and L), RSA, Mg and trehalose; 97.6% of the honey samples were correctly classified by linear discriminant analysis.

Preliminary Study on Effect of Agricultural Activities in Pollen Spectrum of Argentinean Honey

Abstract Honey floral origin is determined by the harversting region, but anthropogenic factors as agriculture expansion might modify the environmental flora and consequently honey floral origin. Argentina is one of the most important honey producers worldwide which, since the 1990s, has undergone an important agriculture transformation by the adoption of transgenic crops like soybean (Glycine max). However, little is known about the effects of this anthropogenic activity on the floral origin of honey or the statistical tools that could be used to analyse it. The objective of the present study was to evaluate the impact that these environmental modifications have on the pollen spectrum of honey. In order to achieve this, thirty-two samples of blossom honey were collected from three different ecoregions of the Buenos Aires province: Parana Delta and Islands, Espinal and Pampa, in two different years: 1999 and 2014. The pollen spectrum of honey samples was determined and the data obtained was analysed with multivariate statistical techniques. It could be concluded that the pollen composition of honeys from different ecoregions has significantly changed in the past years because of agriculture expansion and adaptation of transgenic crops (p=0.007). Honey samples harvested in 1999 were characterized by high values of Helianthus annuus, while in 2014 an important presence of Eryngium sp., Gleditsia triacanthos, Baccharis type, Trifolium sp. and Glycine max was observed. The present results show that honey palynological results and multivariate statistical analysis could be used as a preliminary attempt to evaluate environmental modifications.

Sediment Provenance of the Nansha Trough Since 40 ka B.P. in the South China Sea: Evidence From δ13Corg, TOC and Pollen Composition

Geochemical proxies in organic matter (OM) are considered to be reliable proxies for deciphering types of paleo-vegetation (C3 plants and C4 plants) and their abundance. The contributions of total organic carbon (TOC), stable carbon isotopes (δ13Corg), total nitrogen (TN) and organic carbon to total nitrogen ratios (C/N) were obtained from a gravity core NS07-25 (6°39.945′ N, 113°32.936′ E, water depth 2006 m), extracted from the southern South China Sea (SCS). These data were used to reconstruct the climate changes of the Nansha Trough since 40ka B.P. by comparing them with pollen data from the same core, and this comparison provides better sediment provenance details in the study area. During the periods between 37ka to 27ka, and from 12.5ka to modern day, the majority of terrestrial sediment received from Borneo, and some climatic events have been governed by aeolian fluxes from mid-latitude areas (mainland China). These periods were relatively humid, compared to 27ka to 12.5ka, where the majority of terrestrial sediment came from the Sunda Shelf through riverine pathways. This study serves as the first study to correlate deep oceanic pollen and geochemical proxies in order to identify the weaken terrestrial OM signals in the deep ocean.

Regional and seasonal variation of airborne pollen and spores among the cities of South China

The composition and relative abundance of airborne pollen in urban areas of south China are strongly influenced by geographical location, vegetation, climate, and sampling device. This paper summarizes the latest reports on air pollen for 12 major cities in southern China from 1986 to 2017. The most significant taxa across all sites are Pinaceae, Poaceae, Cupressaceae, and Platanus, making up over 50% of the total airborne pollen in urban environments throughout the years. Clear shifting has been observed from long pollen seasons in the tropics to shorter periods in the south middle and north subtropical regions. There is also a discernible shift in the initiation and length of the pollen season towards higher latitudes. Both reflect the strong influence of solar radiation incidence on pollen production during spring and summer months in the southern urban areas. In this study, the comparison between airborne pollen and meteorological data indicates that the airborne pollen concentration was positively related to temperature but negatively related to precipitation and relative humidity. This study reveals that the consistent wind speed over the year had a very little but positive effect on pollen and spore concentration. The active sampler (volumetric method) in Guangzhou and Zhanjiang collected more spore and pollen species than the passive sampler (gravity method) in other cities. Understanding the future potential impacts of climate change on the phenological cycles and range of allergenic species is a critical step in the advancement of aerobiology studies in south China.

Análise volumétrica do pólen de Attalea funifera Mart. (Arecaceae) em amostras de pólen apícola do litoral do baixo sul da Bahia, Brasil

Foi realizada a análise volumétrica do pólen de Attalea funifera Mart. (Arecaceae) em amostras de pólen apícola comercializadas no município de Nilo Peçanha, Bahia, no período de maio a novembro de 2014. As amostras foram identificadas e quantificadas, no intuito de determinar a origem botânica e a importância de A. funifera na composição do pólen apícola, sob o aspecto volumétrico. O espectro polínico foi composto por 23 tipos polínicos distribuídos em 13 famílias botânicas, tendo como as mais representativas as famílias Fabaceae, Euphorbiaceae e Asteraceae. O tipo polínico mais frequente foi Mimosa pudica, porém, as análises volumétricas apontaram A. funifera como o mais importante na constituição do pólen coletado. Portanto, com base no volume (93.974,70 µm³), verifica-se o potencial do pólen de A. funifera em amostras de pólen apícola e, consequentemente, a importância de análises volumétricas em adição às análises quantitativas e de frequência.

Magnetostratigraphic and archaeological records at the Early Pleistocene site complex of Madigou (Nihewan Basin): Implications for human adaptations in North China

The Nihewan Basin in North China contains the densest concentration of early Pleistocene Paleolithic sites outside Africa. This paper introduces a new archaeological site complex at Madigou (MDG) that was systematically excavated from 2011 to 2014 in the northeastern part of the Nihewan Basin. The site contains fossils and well-preserved stone artefacts in fluvio-lacustrine sediments. Our magnetostratigraphic results situate the MDG sedimentary sequence in the early Brunhes normal chron and the late Matuyama reverse chron, including the Jaramillo normal subchron. The MDG artifact layers are positioned within the pre-Jaramillo Matuyama chron, with an estimated age of ca. 1.2 Ma, close to the onset of Mid-Pleistocene climate transition. The MDG core and flake technology includes bipolar flaking of siliceous dolomite cobbles, and freehand flaking of chert and brecciated chert block fragments. Mammalian fauna and pollen compositions indicate that the MDG hominins lived in an open habitat varying from lightly-wooded grassland to an ecosystem dominated by sparse steppe near the shore of the Nihewan paleolake. Our combined results in the fields of archaeology, paleontology, palynology and magnetochronology suggest that innovations in technological behavior may correlate with adaptations to high environmental variability during the start of Mid-Pleistocene climate transition.

Tropical monodominant forest resilience to climate change in Central Africa: A Gilbertiodendron dewevrei forest pollen record over the past 2,700 years

AbstractQuestionThe existence of monodominant forest in highly diverse tropical rainforest has been the subject of much debate. One hypothesis suggests that the combination of advantageous traits and long periods of low disturbance is key for this forest's persistence. Here we ask whether there is evidence for the long‐term presence of monodominant Gilbertiodendron forest in the absence of fire and climate change.LocationRepublic of Congo.MethodsWe extracted fossil pollen and macro‐charcoal from a sediment sequence collected in present‐day monodominant Gilbertiodendron forest stand that spans the last 2,700 years. Climatic changes were inferred using other published palaeoecological records from Central Africa. We also looked at Gilbertiodendron dewevrei's present‐day ecological tolerances.ResultsGilbertiodendron pollen was found in every sample covering the last 2,700 years in similar percentages to present‐day soil surface samples. In addition, no statistically significant change in pollen composition was found during this time despite vegetation changes being documented in nearby mixed and swamp forest cores over the same time period. No evidence of fire was found for a period of 2,400 years. Only minimal burning occurred over the last 300 years in this monodominant stand. The analysis of ecological tolerances shows G. dewevrei has a broad niche for precipitation (1,300–2,460 mm).ConclusionsOur pollen record is the first to describe the long‐term ecological history of an African monodominant forest. Our results show this monodominant stand existed over the past 2,700 years mostly in the absence of fire, providing support for the low disturbance hypothesis as an explanation for monodominance persistence. However, we show that the monodominant forest was continuous, at this site, despite climatic fluctuations in the immediate region. This combined with the broad tolerance of water requirements of the species suggests a potential resilience to future climate variability. However, additional pollen records from a wider area are needed to confirm this.

The allergen riddle.

An assessment of the taxonomic composition of airborne pollen using targeted high-throughput sequencing may help in understanding environmental and human drivers of the grass pollen season and in allergy prevention and management.

Correspondence between tree pollen emissions sources and pollen content of the ambient air

The article presents the findings, regarding the comparison between the pollen spectrum of the atmosphere in the area and the species composition of pollen emitting trees within the operating range of a Hirst-type volumetric air sampler. The research has revealed how local and transported pollen influence the pollen content of the atmospheric bioaerosol. Even though only a small number of birch trees grow in the area, its pollen proved to be prevalent in the pollen spectrum, while only an insignificant amount of Quercus pollen was detected due to the remoteness of its emission sources from the air sampler. Despite the fact that the highest number of trees in the immediate vicinity of the air sampler belong to the genus Tilia (linden), its pollen made up less than 1% of the pollen spectrum due to entomophily of these trees. Locations of tree pollen emission sources in the immediate vicinity of the Burkard spore and pollen trap were mapped out.

Honeybee Pollen Load: Phenolic Composition and Antimicrobial Activity and Antioxidant Capacity.

Honeybee pollen loads result from the agglutination of pollen grains and salivary secretions of bees. The potential use of honeybee pollen as a food supplement greatly depends on its chemical composition, which varies depending on the botanical and geographical origin of the pollen grains. This study aimed to characterize the botanical origin, chemical composition, and antioxidant and antibacterial activities of honeybee pollen from the V Region of Chile. The introduced species Brassica rapa and Eschscholzia californica predominated in the bee pollen analyzed. The honeybee pollen extracts showed antioxidant and antibacterial properties, specifically against the pathogenic microorganism Streptococcus pyogenes. Quercetin and myricetin were found in all samples in large concentrations. The separation of pollen loads from a multifloral sample demonstrated that E. californica pollen loads are responsible for antibacterial activity. This sample also showed a high concentration of quercetin (304.8 mg/100 g of bee pollen). Based on the present results, honeybee pollen from the V Region of Chile has been found to exhibit antioxidant and antimicrobial activities. Furthermore, it is proposed to use quercetin as a quality indicator for honeybee pollen from this region of Chile. These results should help establish better quality control criteria for Chilean honeybee pollen and its potential use as a functional ingredient.

Actual directions and medical and social problems in clinical allergology: allergens, hidden allergens, food additives, GMO

Global problems affecting all the human kind also affect healthcare, including clinical allergology and immunology, especially in the changing climate and environment conditions. The consequence of these problems is the increase of allergic diseases and immune deficiencies prevalence and severity in the world, as well as the increase in the number and role of «hidden» and the emergence of «new» allergens, the increase in the consumption of food additives, genetically modified foods, etc. In a changing climate and environmental degradation, there is a change in the concentration and role of air pollutants, a change in the composition and properties of pollen as well as household, epidermal, infectious and insect allergens. Climate change and environmental degradation are one of the reasons for the increase of the allergic diseases onset among the elderly and seniors, and for the negative impact on the development mechanisms, course and prognosis of allergy - and immunopathology. All this requires an integrated approach to solve the interrelation problems of health, ecology, climate, etc., and the creation of a global strategy program for new therapeutic approaches and prevention of allergic diseases and immunodeficiency states.

Visiting insect behaviour and pollen transport for a generalist oak-savannah wildflower,Camassia quamash(Asparagaceae)

AbstractMany studies have investigated plant-pollinator interactions using visit records of insects contacting floral reproductive organs. However, these studies may not reflect the effectiveness of visits, since factors such as visitor behaviour and the composition of pollen on their bodies may influence conspecific pollen transfer required for fertilisation in plants. Here we study how pollen transport to a generalist wildflower,Camassia quamash(Pursh) Greene (Asparagaceae), is influenced by the behaviour and body pollen of five functional visitor groups (AndrenaFabricius (Hymenoptera: Andrenidae)/Halictidae (Hymenoptera),Apis melliferaLinnaeus (Hymenoptera: Apidae), BombusLatreille (Hymenoptera: Apidae),OsmiaPanzer (Hymenoptera: Megachilidae), and Syrphidae (Diptera). We found that functional visitor groups differed in their behaviour (BombusandOsmiawere legitimate visitors, contacting both anthers and stigmas) and in the amount of conspecific pollen on their bodies (A. melliferahad the highest levels andAndrena/Halictidae the lowest). Conspecific pollen receipt byC. quamashstigmas was high (>80%), and best explained by visitor behaviour rather than the proportion of visitors with high amounts of conspecific body pollen. Our findings highlight the utility of pollen analyses for understanding pollinator effectiveness.

Climate Changes Record of Bandung Paleolake

The research was carried out on the sediment of Middle Bandung Basin. Samples were taken from a depth of 20 meters to 10 meters, each meter a taken sample for analysis. The characteristics of the sample are greenish grey clay deposits with remnant plant material. Research aims to identify climate change based on palynological data from the Pleistocene-Holocene Boundary. The resulting of radiocarbon dating (14C), shows that age of the sample from the 18 m depth around 11820 years BP. Separation of pollen from sediment used an acetolysis method. Palynomorphs are grouped according to their habitat that related to vegetation zone, i.e., lowland forest zone, submontane forest zone, lower montane forest zone, riparian/open herbaceous swamp vegetation, freshwater algae, and Aquatic plant. The composition of pollen shows a succession of vegetation that reflection of climate changes. From Pleistocene-Holocene boundary at least has been recorded seven times of the shift vegetation zone that is evidence of climate change. The oldest sample at 20 m depth is the coldest temperature occurred in zone one at a depth of 20-19 meters that was dominated by lower montane forest vegetation; the event was around Late Pleistocene. The opposite condition occurred in zone seven at 10 meters depth; temperature becomes warmer that indicated by disappears of pollen submontane forest and dominated by lowland forest pollen similar to the current condition. Climate change is also reflected by fluctuations the quantity pollen of open herbaceous swamp vegetation.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) shows adaptation of grass pollen composition

MALDI time-of-flight mass spectrometry (MALDI-TOF MS) has become a widely used tool for the classification of biological samples. The complex chemical composition of pollen grains leads to highly specific, fingerprint-like mass spectra, with respect to the pollen species. Beyond the species-specific composition, the variances in pollen chemistry can be hierarchically structured, including the level of different populations, of environmental conditions or different genotypes. We demonstrate here the sensitivity of MALDI-TOF MS regarding the adaption of the chemical composition of three Poaceae (grass) pollen for different populations of parent plants by analyzing the mass spectra with partial least squares discriminant analysis (PLS-DA) and principal component analysis (PCA). Thereby, variances in species, population and specific growth conditions of the plants were observed simultaneously. In particular, the chemical pattern revealed by the MALDI spectra enabled discrimination of the different populations of one species. Specifically, the role of environmental changes and their effect on the pollen chemistry of three different grass species is discussed. Analysis of the group formation within the respective populations showed a varying influence of plant genotype on the classification, depending on the species, and permits conclusions regarding the respective rigidity or plasticity towards environmental changes.

Dryland organic farming increases floral resources and bee colony success in highly simplified agricultural landscapes

Agricultural intensification has contributed to declines in wild bee populations at local and regional scales. The Northern Great Plains is a key region for small grain, forage, pulse, and oilseed production, yet the impact of available floral resources on colony success of eusocial bees is unknown. To assess the effects of farming system on bee colony success (relative growth rate and fecundity) and worker condition (lipid content and wing wear), we placed 60 mini-colonies of Bombus impatiens in six conventional and six organic spring wheat fields near Big Sandy, Montana, USA over two growing seasons. Consistent with our expectations, we found that flower density and forb richness were positively associated with colony relative growth rate and fecundity. Similarly, flower density, forb richness, and the relative growth rate and fecundity of B. impatiens colonies were greater in organic fields when compared to conventional fields. Workers from organic fields had lower mean wing wear and marginally greater average body lipid content. However, there were no differences in the number of reproductives (queens, workers, and males) between two systems. Lastly, though the overall composition of colony-collected pollen was not different across the farming systems, colony-collected pollen species richness was greater in organic fields in one of the two sampled growing seasons. We conclude that by increasing B. impatiens colony success and individual worker condition, the greater floral resources observed in organic systems can contribute to better biodiversity-based indirect ecosystem services in the highly simplified agricultural landscapes that dominates the Northern Great Plains.

A Synthesis of Pollen Composition in Prehistoric Cultivation Layers in Southwestern Norway

ABSTRACT Pollen records and radiocarbon dates from cultivation layers were compiled to explore agricultural changes in southwestern Norway, with a focus on cereals and associated herbs. Variations in the pollen composition were examined using rarefaction and multivariate analyses. The results showed that prehistoric cultivation layers were preserved in the region from c. 2200 BC to AD 1400. That the landscape was open and dominated by grassland is inferred from the preponderance of grass and other herbaceous pollen, originating from meadows and pastures. A few annual weeds were associated with cereals, such as Spergula arvensis and Polygonum persicaria. The main change in our record occurred during the Early Iron Age (c. 500 BC-AD 600), when cultivated fields and grassland expanded at the expense of woodland, and was probably associated with the establishment of permanent fields and hay-meadows. This study shows that pollen analysed from cultivation layers can be synthesised to provide a regional picture of land-use development.