Palynological Research Articles

Melissopalynology Characterization of Pakistani Honey

The aim of the study was to add latest scientific information regarding bee flora through pollen analysis available for honeybees in different districts of Punjab province, Pakistan. A total of 50 honey samples, natural (n=32) and branded (n=18) were collected and examined as per the method recommended by International Honey Commission. Natural honey samples were collected from beekeepers. Pollens of families Poacea (26.5%), Azadirachta spp. (22%), Citrus spp. (17.45%), Pisum spp. (16.41%), Ziziphus spp. (13.99%), Prosopis spp. (13.13%), Brassica spp. (8.57%), Malvacea (8.08%), Syzygium spp. (7.29%), Cassia spp. (6.2%), Acacia spp. (5.17%) and Eucalyptus spp. (4.35%) were common in both branded and fresh honeys. Whereas Morus spp. (8.5%), Moringa spp. (4.46%), Psidium spp. (4.23%), Bombax spp. (1.9%), Mangifera spp. (1.9%) were found in fresh honeys only. Similarly, four different types of Pollens (Melilotus spp. (8.6%), Alfa spp. (6.4%), Benincasa spp. (6.4%) and Halianthus spp. (4.3%)) were detected exclusively in various branded honeys Muqeet (n=4), Sary (n=2), Swat honey, Marhaba (n=3), Youngs (Beehive), Ubqari, Salman (Pak honey) Al-Shifa, Ponam, Langanase and Aftab Qarshi. There was a correlation (r=0.24) between pollens of same taxa and families in branded and fresh honeys. High quality pictures were taken by camera fitted on light microscope.

Cerebral neurotoxicity of amino-modified polystyrene nanoplastics in mice and the protective effects of functional food Camellia pollen

Accumulating evidence suggests that nanoplastics contribute to an increased risk of brain damage, however, the precise underlying mechanisms remain unclear. Here, we subjected mice to long-term exposure to amino-modified polystyrene nanoplastics (APS-NPs). These nanoplastics were detected in the mouse brain; coupled with the observed upregulation of Alzheimer's disease-associated genes (APP and MAPT). To further explore nanoplastic damage mechanisms and the corresponding protective strategies against these mechanisms in vitro, we used hCMEC/D3 and HT22 cells. Results showed that APS-NPs disrupted tight junction proteins (Occludin and ZO-1) via TLR2/MMP9 axis, resulting in blood-brain barrier permeation; this was significantly mitigated by functional food Camellia pollen treatment. APS-NPs initiated iNOS and nNOS upregulation within neurons resulting in Sirtuin 1 deacetylase inactivation and CBP acetyltransferase stimulation, ultimately leading to Ac-Tau formation. This process was attenuated by Camellia pollen, which also ameliorated the APS-NPs-induced neuronal apoptosis mediated by the p53/Bax/Bcl-2 axis. Network pharmacology analysis of Camellia pollen offered a further theoretical understanding of its potential applications in preventing and treating nervous system disorders, such as Alzheimer's disease. This study established that Camellia pollen protects the brain against APS-NPs-mediated blood-brain barrier damage and alleviates neuronal apoptosis and Alzheimer's disease-like neurotoxicity. This study elucidates the mechanisms underlying polystyrene-induced brain damage and can be used to inform future prevention and treatment strategies.

Late Quaternary Dynamics of Landscape and Climate in the North of the West Siberian Plain Revealed by Paleoecological Studies of Peat and Lake Sediments

West Siberian mires covering more than 50% of area in the subarctic are still poorly investigated despite their thick peat sediments suitable for paleogeographic research of past long-term landscape and climatic changes. In this research, a combination of paleoecological methods were used, including the analysis of pollen, spores, diatoms, NPPs, and macrofossils, the measurement of peat humification, and quantitative paleoclimate reconstruction. This multi-proxy approach was applied to study a palsa bog (frost peat heave mound) located in the north of western Siberia on the border of the northern taiga and forest–tundra (65°18′56″ N, 72°52′27″ E). Chronology is based on 21 radiocarbon dates, which were calibrated in CLAM. Studies have shown that sediments of palsa bog Nadym of a 1050 cm thickness were formed both in the Holocene and earlier periods of the Quaternary. Radiocarbon dating worked well for peat sequences (610 cm thick), but failed for underlying lacustrine and mineral sediments (440 cm thick). Numerous remains of salt-water diatoms and exotic Neogene pollen were found in the lacustrine sediments (650–850 cm). The oldest sediments (850–1050 cm) have signs of secondary epicryogenic diagenesis in the form of cryogenic iron-enriched granules. Both lacustrine and bottom sediments contain abundant coniferous pollen. At the same time, spore–pollen complexes dated to the Last Glacial Age were not found in low sediments because of failed dates. To explain this, the authors turn to the hypothesis of glyacioisostatic compensation, according to which the study area was uplifted during the Last Glacial Age and the ancient deposits underwent secondary diagenesis in subaerial conditions. Holocene lacustrine sedimentation began to form about 9800 cal. a BP. These lacustrine sediments turned out to be enriched in redeposited Neogene pollen and diatoms. It was interpreted as an influence of excess humid climate in combination with geological subsidence of landscape in the study area during the Early Holocene. This caused lake formation and introduction of exotic microfossils via surface run-off from higher-relief areas in the catchment. Syngenetic sedimentation in the Nadym section is associated only with peat-mire deposits covering the last 8400 cal. a BP. For this time, the dynamic of vegetation cover and quantitative changes in paleoclimate were reconstructed using spore–pollen, macrofossil, humus, and NPP data as well as the information–statistical method of V.A. Klimanov. The spore–pollen analysis revealed four main phases in the development of vegetation cover: 1. Spruce–birch forests with open meadows and lakes (8400–7600 cal. a BP); 2. Dominance of spruce forests and thawed eutrophic (minerotrophic) mires (7600 to 6500 cal. a BP); 3. Coniferous–birch forests and thawed mesotrophic mires (6500 to 4500 cal. a BP); 4. Birch–pine forests and oligotrophic (ombrotrophic) bogs with permafrost mounds—palsa bogs (approx. the last 4500 years). Quantitative reconstructions of paleoclimate based on pollen data show that in most cases the periods of a sharp decrease in mean January and mean July temperatures coincided with episodes of low solar activity. The assumption was made about the determining influence of solar activity on the formation of permafrost in the soils and mires of the study area. Sun minima caused permafrost formation in the mire periodically since 8400 cal. a BP in study peatland, but complete freezing of the peat mire and formation of the palsa bog occurred at c. 2800 cal. a BP.

Variability of East Asian Summer Monsoon precipitation during the Early Pleistocene based on pollen analysis from the western Loess Plateau, China

Understanding Early Pleistocene variability in precipitation associated with the East Asian Summer Monsoon (EASM) may help improve understanding of the effects of future global warming on this system. In this study, a quantitative EASM precipitation record with ∼2.7 kyr resolution was reconstructed for the Early Pleistocene (∼2.2–1.7 Ma) based on a pollen record from a loess-paleosol sequence in Lanzhou Basin, on the western Chinese Loess Plateau (CLP). The results show that the average annual precipitation (Pann) value was ∼505 mm, almost ∼1.6 times as much as today (∼310 mm), implying much stronger EASM intensity from ∼2.2–1.7 Ma. The EASM experienced a period of stronger intensity from ∼2.2 to 2.07 Ma, with Pann up to ∼525 mm and vegetation dominated by forest-steppe, as well as a period of weaker intensity between ∼2.07 and 1.99 Ma with lower average Pann (∼481 mm) and steppe dominated vegetation. A gradual intensification followed from ∼1.99 to 1.7 Ma, with increasing Pann (∼503 mm) accompanied by a significant increase in arboreal abundance. Our analysis suggests that the west to east temperature gradients across the Equatorial Pacific region influenced the Early Pleistocene EASM evolution over geological timescales. This finding differs from the traditional view that high-latitude ice sheet fluctuations were the primary driving force of Quaternary EASM. On orbital timescales, the Pann exhibits a dominant ∼41 kyr obliquity periodicity between ∼2.2–1.99 Ma and a ∼18 kyr precession periodicity between ∼1.99–1.7 Ma, indicating that Northern Hemisphere ice sheet and low-latitude solar insolation were the dominant drivers of EASM precipitation cycles in these two periods.

Coastal Lagoonal Evolution within the Early Holocene Humber Estuary, eastern England

ABSTRACTRapid sea‐level rise during the Early Holocene around the North Sea coastal lowlands provided conditions under which estuarine and coastal features, with no modern equivalents, could be created. Investigation of nearshore sediments within the Outer Humber Estuary, UK, has identified a tidal lagoonal system, created between c. 9000 and 7800 cal a bp. These sequences show the initial flooding of a carr woodland, prior to the establishment of more saline conditions as the tidal lagoonal system developed. Inter‐core comparisons, based on diatom and pollen analyses, suggest variations in the structure of a tidal lagoon setting, which probably lasted for only a brief period before being submerged by rising sea levels. The absence of an erosive contact in several of the sequences studied has permitted the creation of the oldest sea‐level index points for the Outer Humber Estuary, providing validation for the current glacial isostatic adjustment models for the region.

Revealing the intricate microcosm: Advancing invasive species pollen analysis through scanning microscopy of ultra sculpture.

Micromorphological visualization of plant surface peculiarities provides valuable characters for the precise identification of plant species. Invasive alien species, introduced outside their native range, pose significant ecological, and health challenges. This study focuses on micromorphological investigations of selected invasive plant species belonging to the families Amaranthaceae, Asteraceae, Moraceae, Crassulaceae, Cannabaceae, Fabaceae, Commelinaceae, and Oxalidaceae. The study employs scanning electron microscopy (SEM) to analyze the species micromorphology of pollen structure in depth to characterize the sculpturing patterns. Additionally, the study examines the pollen characteristics of these invasive plants, including shape, size, and fertility, along with exine sculpturing. The maximum polar diameter was observed for Senna tora (41.2 μm). The spines in Achillea fragrantissima were measured to have dimensions of approximately 1.91 μm in length and 2.11 μm in width. The findings shed light on the allergy-causing potential of these invasive species, providing crucial information for accurate identification and effective management strategies to safeguard the indigenous flora of the region. The study contributes to the knowledge base for botanists, taxonomists, policy makers, climate experts, and biodiversity specialists. RESEARCH HIGHLIGHTS: Integrating SEM to analyze the pollen of invasive species. Unveiling pollen micromorphology of invasive species. Exploring the microscopic realm of invasive pollen to accurately identify the species.

The vegetation history of Lake Mert and its surroundings for the last 6600 years (Kırklareli, NW Türkiye)

The primary aim of this study is to determine the Middle-Late Holocene vegetation history of the İğneada Longoz (Floodplain) Forests around Lake Mert, located in Kırklareli, using high-resolution palynological analysis conducted on the MRT-04 core. Pollen analyses was performed on sediment samples collected from 67 different levels within the core. Pollen counting and identification were performed using a Leica DM750 light microscope, with a minimum of 500 terrestrial pollen grains counted per sample. The age of the lake was determined to be 6600 years old through radiocarbon dating of the core. According to the findings from the pollen analysis, deciduous mixed oak forests have dominated the region in and around Lake Mert for the past 6600 years. Within these mixed oak forests, Quercus cerris type (deciduous oaks) is predominant, with notable contributions from Fagus, Carpinus, Corylus, and Tilia. This forest composition has displayed a consistent pattern, except for changes attributed to the expansion of temperate species and human influences. The distribution of mixed oak forests began to decline around 1360 BP, coinciding with a significant increase in the presence of Alnus, Fraxinus, and Ulmus. These trees are characteristic species of floodplain forest and indicate the initiation of the formation of the İğneada Longoz Forests after 1360 BP. Furthermore, around 420 BP, there was a substantial decrease in the pollen percentages of Quercus and Fagus. During this period of declining mixed oak forests, Plantago and Ambrosia appeared for the first time in the pollen diagram. The reduction in arboreal plant taxa and the rise of herbaceous taxa such as Plantago, Ambrosia, and Poaceae, which serve as indicators of human impact, signify the conversion of forested areas into agricultural and pasture lands.

Human-induced fires and land-use change in Lubusz Land (western Poland) derived from Lake Lubińskie sedimentary record

Sediments of Lake Lubińskie were investigated to track human-induced vegetation and fire activity changes in Lubusz Land (western Poland). Geochemical data, as well as pollen, macrocharcoal, and statistical analyses (CONISS, CharAnalysis, PCA, BINCOR) allowed us to recognize the major phases of the human impact. At the beginning of the investigation period, 3000 years ago, the area had already experienced disturbances from humans caused by the Lusatian and Przeworsk cultures, followed by western Slavs, and modern society. Land cover changes were mostly related to deforestation and gaining arable lands. The forest communities shrank substantially also due to timber demand from the growing society. However, the pollen record shows that within the last ~50 years the area experienced forest regeneration. Wildfires played an important role in shaping the landscape in the area of Lake Lubińskie. Overall, 23 fires were identified within the profile showing relatively high fire frequencies (up to 4.8 fires per 500 years) between 600 −38/+36 BCE and 1 ± 206 CE as well as between 1065 ± 98 CE and 1380 ± 92 CE. The highest fire frequency was observed between the 1000s and mid-1400s, showing decreased fire return interval (FRI) and increased charcoal flux as well as progressive deforestation. These changes were related to the establishment of villages (e.g., Lubin village) and the presence of the Joannites. Fire was most commonly used as a land management tool to gain patches of land for agrarian purposes. PCA and BINOCR analyses suggest that most of the fires were set by humans, but natural causes of ignition cannot be excluded. The land-use changes affected the vegetation in the region, causing increased erosion and shifts in the geochemistry of the lake reflected in better bottom waters ventilation and progressive eutrophication.

Comparison of paleobotanical and biomarker records of mountain peatland and forest ecosystem dynamics over the last 2600 years in central Germany

Abstract. As peatlands are a major terrestrial sink in the global carbon cycle, gaining an understanding of their development and changes throughout time is essential in order to predict their future carbon budget and potentially mitigate the adverse outcomes of climate change. With this aim to understand peat development, many studies have investigated the paleoecological dynamics by analyzing various proxies, including pollen, macrofossil, elemental, and biomarker analyses. However, as each of these proxies is known to have its own benefits and limitations, examining them in parallel allows for a deeper understanding of these paleoecological dynamics at the peatland and a systematic comparison of the power of these individual proxies. In this study, we therefore analyzed peat cores from a peatland in Germany (Beerberg, Thuringia) to (a) characterize the vegetation dynamics over the course of the peatland development during the late Holocene and (b) evaluate to what extent the inclusion of multiple proxies, specifically pollen, plant macrofossils, and biomarkers, contributes to a deeper understanding of those dynamics and interaction among factors. We found that, despite a major shift in the regional forest composition from primarily beech to spruce as well as many indicators of human impact in the region, the local plant population in the Beerberg area remained stable over time following the initial phase of peatland development up until the last couple of centuries. Therefore, little variation could be derived from the paleobotanical data alone. The combination of pollen and macrofossil analyses with the elemental and biomarker analyses enabled further understanding of the site development as these proxies added valuable additional information, including the occurrence of climatic variations, such as the Little Ice Age, and more recent disturbances, such as drainage.

From the Ground Up: Examining the Role of Pollen and Soil Analysis in Forensic Investigations

From the Ground Up: Examining the Role of Pollen and Soil Analysis in Forensic Investigations

Sedimentation Processes and the Holocene Evolution of the Indigirka Paleovalley (Coastal Shelf Area of the East Siberian Sea)

Problems of the paleogeographical evolution and changes in sedimentation environment within the Indigirka River paleovalley (the East Siberian Sea) are discussed. Based on the results of geophysical and geological research and a high-resolution study of sediment cores (grain size analysis, geochemistry, macro- and micropaleontology, pollen analysis, radiocarbon dating) the development of the Holocene marine transgression has been reconstructed, sedimentation rates have been calculated, and the basic principles of changes in sedimentation processes have been established.

High-performance thin-layer chromatography‒multi-stage mass spectrometry methods for analyses of bee pollen botanically originating from sweet chestnut (Castanea sativa Mill.)

High-performance thin-layer chromatographic (HPTLC) silica gel and amino plates in combination with developing solvents containing formic and acetic acid were examined for HPTLC‒multi-stage mass spectrometry (MSn) analyses of chestnut bee pollen samples from Slovenia and Türkiye. Ethyl acetate‒formic acid‒acetic acid‒water (10:1.1:1.1:2.6, V/V) and ethyl acetate‒dichloromethane‒formic acid‒acetic acid (10:2.5:1:1.1, V/V) were used for development of silica gel and amino plates, respectively. Twofold pre-development was required for the developed HPTLC‒MSn methods. The first pre-development was performed with methanol‒formic acid (10:3, V/V) for silica gel plates and methanol‒formic acid (10:5, V/V) for amino plates. The second pre-development with methanol was equal for both types of the plates. Using the developed HPTLC‒MSn methods, five phenylamides (spermidines), six isorhamnetin glycosides and gluconic acid were identified in both chestnut bee pollen samples. Glycosylated phenolic acid (caffeic acid-hexoside) was detected only in the Turkish bee pollen sample. To the best of our knowledge, this is the first report on isorhamnetin-(hexosyl)hexoside, isorhamnetin-acetylhexoside, isorhamnetin-(pentosyl-deoxyhexosyl)hexoside and caffeic acid-hexoside in chestnut bee pollen. This is also the first report on isorhamnetin-(pentosyl-deoxyhexosyl)hexoside and caffeic acid-hexoside in any bee products.

Comparative analysis of the physicochemical, proximate, and antioxidant characteristics of stingless bee (Meliponula beccarii) honey from modern and wild beehives in Ethiopia.

There is a dearth of information on the comparative studies of the physicochemical, proximate, and antioxidant properties as well as quality standards of stingless bee honey (SBH) in Ethiopia. Hence, this study was designed to assess and compare the physicochemical, proximate, and antioxidant properties of SBH, specifically sourced from Meliponula beccarii, and produced under both wild and modern apiary conditions at two distinct geographical locations. A total of forty-six honey samples were meticulously collected from domesticated stingless bee colonies and naturally occurring wild nests at Wolmera and Cheliya districts. Pollen analysis unveiled eleven distinct bee plant species distributed across six families, with Asteraceae being the most prevalent, primarily represented by Guizotia scabra and Vernonia amygdalina. Notably, the physicochemical, proximate, and antioxidant properties of SBH collected from modern pot hives exhibited significant variances (p < .05) when compared to SBH from wild nests. Principal component analysis (PCA) delineated the differentiation of SBH sources based on both geographical location and the type of beehive. One-way ANOVA corroborated these distinctions, underscoring significantly higher levels (p < .05) of ash, electrical conductivity, free acidity, hydroxymethylfurfural, sucrose, total phenolic content, total flavonoid content, and radical scavenging activities of SBH from modern pot hives in Wolmera. Whereas, Cheliya modern pot hives recorded higher values in pH, hydroxymethylfurfural and maltose contents compared to the wild nest SBH. Further analysis through Pearson correlation highlighted a strong positive association between total phenolic content and total flavonoid content with the antioxidant capacity of SBH. These findings underscore the significance of integrating modern pot hives to enhance the quality of SBH within Ethiopia's beekeeping sector.

Fourth and fifth seasons of the Nubian Archaeological and Anthropological Expedition of the Anuchin Research Institute and Museum of Anthropology, Lomonosov Moscow State University at the Sites of Deraheib and Onib (the Republic of Sudan). Part I. Survey

Introduction. The Nubian expedition of the Lomonosov MSU carried out survey in the Onib Depression in December 2022. The survey revealed several surface scatters and two stone age sites Onib-1 and Onib-Outcrop. Materials and methods. The materials for the article were artifacts (stone tools and debitage, fragments of ceramics) discovered at the surface scatters and sites as well as samples for OSL dating, loss-on-ignition and pollen analysis taken from sites. For comparison, we used stone tools discovered by the Nubian expedition of the USSR Academy of Sciences in 1961-1963. The artifacts found at the sites were documented (marked on a map, photographed and described). Several samples for OSL dating were taken at both sites. Sample preparation and gamma spectrometry, as well as OSL measurements, were conducted by standard methods. Analysis of the decoration of ceramic fragments found at the Onib-1 site was carried out. Also, based on the prepared thin sections, a technological and petroglyphic analyses of the obtained fragments were carried out. Samples were taken from different layers of the sites Onib-1 and Onib-Outcrop to determine the content of organic residues and spore-pollen analysis. Sample preparation and analysis were carried out following the standard procedures. Results and Discussion. Analysis of the finds made at the sites indicates that the entire Wadi al-Allaqi region from the Red Sea Mountains to the Nile Valley was inhabited during the Neolithic period. OSL dating for Onib-1 and Onib-Outcrop sites indicates that the sedimentary deposits were formed during the Neolithic Subpluvial. These data are also confirmed by the results of ceramic analysis. The layers in which the ceramic fragments were found can be dated back to the 3rd millennium BC. Petrographic analysis of thin sections of ceramics from Onib-1 site indicates the use of local material for the manufacturing of ceramics. The results of loss on ignition analysis did not reveal a sufficient content of organic residues for a comprehensive paleoecological study that overall indicates unfavorable conditions for the accumulation of organic matter in the studied deposits. Conclusion. The results obtained indicate high prospects of continuing field research in the Onib Depression aimed at discovering and excavating Neolithic sites. @ 2023. This work is licensed under a CC BY 4.0 license

Modern pollen assemblages from the hinterland of the Tibetan Plateau and their significance for reconstructions of past vegetation

We conducted a detailed field vegetation investigation combined with the collection of surface soil samples for pollen analysis in the alpine meadow and steppe vegetation zones (30 sites in each zone) in the hinterland of the Tibetan Plateau. Our objectives were to determine the source area of exotic pollen, the relationship between pollen percentages and the cover of the major plant taxa, and the characteristics of the pollen assemblages from surface soils and lake sediments and their vegetation significance. Our principal findings are: (i) the two vegetation zones are herbaceous although arboreal pollen types are present in the related pollen assemblages (2 and 16.8% in the alpine meadow and steppe zones, respectively); (ii) arboreal pollen is assumed to be transported mainly by the Indian monsoon from the forests of the southern Himalayan foothills or river valleys – the spatial distribution of the percentages and concentrations of arboreal pollen in the study sites shows that pollen concentrations have the strongest correlation with the Indian monsoon's variations; (iii) there are regional differences in (a) the relationship between pollen percentages and the cover of the main plant taxa and (b) the indicator plant taxa representative of pollen assemblages and vegetation types zones – the regional vegetation of the study region and pollen productivity variations between plant taxa are likely to be the main causes behind these differences; and (iv) the pollen assemblages from surface soils and lake sediments have similar characteristics and correspond well to the regional vegetation of the alpine meadow zone. In the alpine steppe zone, the pollen assemblages from surface soils and lake sediments are quite different, caused mainly by the over‐representation of Artemisia. Our study supplies a detailed description of pollen–vegetation relationships on the hinterland of the Tibetan Plateau and provides scientific references for interpreting stratigraphic pollen assemblages and reconstructing regional vegetation.

Pollen reveals the diet and environment of an extinct Pleistocene giant deer from the Netherlands

Pollen analysis of five teeth (two premolars, three molars) from a single maxilla of a giant deer (Megaloceros giganteus) found in Pleistocene deposits in The Netherlands reflects the diet and the landscape of the specimen that lived in eastern Doggerland. Apiaceae (among which Anthriscus sylvestris, Heracleum and Hydrocotyle), Asteraceae (among which Anthemis-type, Senecio-type and Cichorioideae), Filipendula, Poaceae and Symphytum were among the ingested plants. The landscape had dense, species-rich tall-herb vegetation and an open tree layer of Alnus and Betula, whereas thermophilous tree taxa were absent. Climate was probably cool-temperate, semi-dry, sub-continental. A radiocarbon date of the maxilla is beyond the 14C detection limit. We conclude that our giant deer most likely lived during the early Eemian or during an early Weichselian interstadial.

Modern pollen assemblages of agricultural land, wasteland, and natural vegetation in China and their significance for reconstructing the intensity of agricultural activity

Knowledge of the modern pollen assemblage characteristics of artificial and disturbed vegetation can help reconstruct changes in the intensity of human activity and land use/land cover (LULC) based on Holocene stratigraphic pollen records. We obtained pollen assemblage data from 217 agricultural land (cultivated cereals) sites, 79 wasteland sites, and 389 natural vegetation sites in different regions in China. The results show that the pollen of cereals Poaceae and the associated agricultural weeds in agricultural land and wasteland vegetation contexts are effective indicators of the intensity of agricultural activity, and that the pollen assemblages of natural vegetation accurately reflect the regional zonal vegetation composition. Although the cereals Poaceae proportion varied greatly among the agricultural sites in different regions, due to factors like cultivation practices, crop types, and terrain, all of them were significant indicators of agricultural activity. The pollen assemblages of wasteland and natural vegetation in different regions were also different, and the indicator taxa exhibit distinct zonal characteristics. There was no consistent linear relationship between cereals Poaceae proportion and the area of agricultural land. The cereals Poaceae proportion did not vary with increasing agricultural area in regions with higher or lower levels of agricultural production; only in Northeast and North China, when the agricultural area was below 60%, did the cereals Poaceae proportion increase with increasing agricultural area. These results provide a modern process basis for the use of stratigraphic pollen data to reconstruct past changes in agricultural activity and LULC.

Palaeoecological multiproxy reconstruction captures long-term climatic and anthropogenic impacts on vegetation dynamics in the Rhaetian Alps

Alpine ecosystems are particularly affected by climate change due to their high sensitivity to temperature variations. Understanding the response of vegetation to rapid temperature increase and human impact is necessary to produce accurate and reliable predictions of future mountain vegetation and mitigate climate change impacts. Our multiproxy study reconstructs climate, fire, and vegetation dynamics over the last 14,200 cal. BP at Lai da Vons (1991 m a.s.l.), a subalpine lake situated in the treeline ecotone in Eastern Switzerland. Our results based on geochemical analysis (XRF), pollen and charcoal analysis, and high-resolution macrofossil analysis reveal that early afforestation started already at the onset of the Holocene, dominated by Pinus cembra and Larix decidua. Larch and stone pine formed closed forests at the site at 10,300 cal. BP. From 9500 cal. BP onwards, when summer temperatures were warmer than today, Picea abies expanded simultaneously with Abies alba. In the past 6500 years, increasing human impact, culminating during two main phases of landscape opening and intensification of fire regime, led to a progressive increase of species richness. Considering future climate change, an upward shift of treeline and timberline is expected in the absence of domesticated herbivores. We advocate that low-intensity pastoralism in such a cultural landscape is essential to preserve the plant diversity of species-rich mountain meadows.

Paleoecological history of Eleuthera Island, the Bahamas, based on pollen and charcoal analyses from two lakes

Paleoecological history of Eleuthera Island, the Bahamas, based on pollen and charcoal analyses from two lakes

Floral resources of Epicharis flava (Hymenoptera, Apidae) in an urban area, detected from the pollen spectrum in the scopae

Bees are the main pollinators of terrestrial ecosystems and, among them, we can highlight oil-collecting bees, which show different morphological and behavioral adaptations associated with plants that offer this floral resource. Floral oils are used in provisioning, building, and lining the brood cell and nests. The genus Epicharis has a neotropical distribution and females are closely associated with plants of the Malpighiaceae family, with the highest number of records in species of the genus Byrsonima. However, due to the strong seasonality of adult activity and solitary behavior, knowledge about important floral resources to Epicharis bees is still scarce. In order to identify important resource sources for a widely distributed species, the current work aimed to analyze the pollen spectrum of Epicharis flava Friese in an urban area in the Atlantic Forest domain. For this, females of E. flava were captured during five days while visiting flowers of Byrsonima sericea DC. (Malpighiaceae) in an urban area, and the pollen load in their scopae was submitted to acetolysis processing for further analysis under the microscope. In total, 71 pollen types were found, with emphasis on Fabaceae, Solanaceae, Bignoniaceae, and Malpighiaceae, considered sources of nectar, pollen, and floral oils. This study made it possible, through the analysis of pollen in the scopae, to identify a list of potentially important species for the maintenance of E. flava populations. This information is necessary for the management of urban green areas, aiming at increasing biodiversity. In addition, these data can serve as a base for further research on oil-collecting bees in the Neotropics.