Non-arboreal Pollen Research Articles

Unravelling 6000 years of interplay among environmental changes, anthropogenic activities, and Vesuvius eruptions in the upper Sarno Plain (Campania, Italy)

Abstract Pollen analysis was carried out on the infilling succession of the Fossa San Vito sinkhole, at the NE foothills of the Sarno Plain (Italy). Four 14C dates and six tephra layers constrain the pollen sequence between ca. 6000 and 500 cal yr BP. A forested environment, with a few signs of human activities, characterizes the pre-protohistoric period (ca. 6000–2750 yr BP). Stability of the arboreal pollen grains to non-arboreal pollen grains (AP/NAP) curve is due to climate-related opposite oscillations of deciduous and evergreen forest. In this period, the pyroclastic products from Neapolitan volcanoes that reached the upper Sarno Plain seem to have affected neither vegetation nor human activities. In the archaic and classic periods (ca. 2750–1500 yr BP), intensive deforestation and increase in anthropogenic indicators indicate the occurrence of grazing and crop activities managed by the main urban centers located in the plain: Pompeii, Stabiae, and Nuceria. After the Pompeii eruption in CE 79, a rapid re-afforestation and decline in all anthropogenic indicators testify to the temporary abandonment of the area, linked to the disastrous demise of the main economic centers. The upper plain was repopulated and exploited in the Late Ancient and Middle Ages (ca. 1700–500 yr BP), as indicated by the increase in all crop and grazing indicators.

Label-free quantitative phase imaging and analysis of airborne pollen

Abstract Pollen morphology, involving the physical characteristics of pollen grains from seed plants during reproduction, plays an important role in plant biology, ecology, and evolution. High pollen concentrations in the air can degrade air quality and exacerbate respiratory conditions such as asthma. Understanding pollen morphology and its implications for air quality is significant for mitigating respiratory health risks. Conventionally, fluorescence microscopy is used for pollen imaging, but photobleaching, quenching, and phototoxicity affect the surface morphology and do not provide quantitative data on the pollen grains. For this study, we used bright field (BF) imaging and quantitative phase imaging (QPI), a label-free interferometric microscopy method, to look at differences in the shape of pollen. BF imaging provides information about the shape and size of the different pollens but has a limitation of low contrast. To obtain high-contrast images and quantitative data on the pollen grains without any exogenous agents, we employed QPI and BF imaging in the present study. QPI enables the extraction of detailed information regarding the cell wall, aperture, and thickness of pollen while also maintaining their natural state without the need for chemical treatments. In the present work, we sampled the ambient air from May 2023 to January 2024 on the IIT Delhi campus. Subsequently, QPI and BF imaging have been done for pollen identification and phase analysis of arboreal and non-arboreal pollen. Further, by utilizing the information obtained from BF microscopy and QPI, different species of pollen have been identified, and a pollen calendar has been prepared for exhibiting pollen season throughout the year. To the best of the authors’ knowledge, they have conducted the QPI of airborne pollen grains for the first time; this technique holds great potential for characterizing airborne pollens without the need for staining or sample preparation.

Modern pollen distribution along a Himalayan elevation gradient in Central Nepal

Modern pollen distribution and its relationship to environmental variables in tropical to alpine vegetation zones are investigated to provide a reference for palaeoenvironmental reconstructions and to improve the understanding of pollen dispersal patterns in Central Nepal. A total of 100 samples (from soil and moss) were collected from along an elevational gradient ranging from 173 to 4615 m above sea level. Results show that the alpine zone is dominated by arboreal pollen (AP) and the sub-alpine zone also shows good representation of coniferous taxa pollen such as Pinus, Abies, Tsuga, and Picea along with Ericaceae. The temperate zone has a good representation of Quercus (Evergreen) and Pinus pollen, whereas the sub-tropical zone is characterized by Alnus pollen and agricultural taxa such as Cerealia (planted Poaceae) and Brassicaceae. In the tropical zone, non-arboreal pollen (NAP), mainly Cerealia dominate, reflecting intensive agricultural practices. Shorea is completely silent in pollen representation. A redundancy analysis indicates that elevation is the primary factor influencing pollen distribution in this region. Overall, the pollen data reflect the vegetation distribution but Pinus is over-represented and Shorea is unrepresented, which should be taken into consideration when interpreting fossil pollen in Central Nepal.

Modern vegetation-climate relationships for pollen assemblages across the mountainous regions of southwestern China: Implications for palaeoenvironmental reconstruction

A comprehensive understanding of modern pollen transport processes is a prerequisite for utilizing fossil pollen to elucidate the evolution of palaeoclimates and palaeoenvironments, especially in areas such as southwestern China where complex mountainous topography results in vegetation heterogeneity. In this paper, we selected four vertical profiles in mountainous regions of southwestern China, each with distinct plant communities, to investigate the relationship between modern pollen rain, vegetation types and vegetation cover, and to quantify the influence of environmental factors. Results show that pollen assemblages are generally representative of regional plant communities, although long-distant transport of arboreal pollen by valley winds can introduce signals from a much wider area. The calibrated arboreal pollen percentage (AP) and ratio of arboreal pollen to non-arboreal pollen (AP/NAP) serves as reliable quantitative proxies for vegetation cover, highlighting the importance of appropriate calibration when interpreting fossil pollen assemblages. Climate is the primary determinant of pollen distribution across these mountains, with mean temperature of the coldest month (MTCM) playing the most prominent contribution. Additionally, the impact of vegetation cover and soil nutrients on pollen distribution are also significant. Our modern study improves the accuracy of pollen interpretation for palaeoenvironmental reconstruction in mountainous regions of southwestern China.

The impact of temperature on increased airborne pollen and earlier onset of the pollen season in Trentino, Northern Italy

The impact of climate change on ecosystems can be assessed through pollen dispersion data, which acts as a proxy for the plant flowering stage. The aim of this study is to verify if changes occurred in the season and concentration of airborne pollen in Trentino (Northern Italy), and to evaluate if temperature (T), precipitation (P), and/or land use influenced such changes in the period 1989–2018. Airborne pollen, sampled by a Hirst-type trap, was analyzed by light microscopy, and pollen concentrations were obtained. Twenty-four taxa, covering 95% of the local pollen spectrum, were considered for this study. A significant upward trend in annual pollen integral (APIn) is the main outcome over the study period. The increase in APIn is more evident when analyzing the data in three decadic blocks, both for all the considered taxa (+ 58%) and for Arboreal Pollen (AP; + 155%). Considering both the annual data and the decadic blocks, APIn shows a significant positive trend for Cupressaceae/Taxaceae, Ulmus, Populus, Salix, Ostrya, Quercus, Olea (AP), and Plantago, Cannabaceae, Ambrosia (non-arboreal pollen, NAP); a significantly earlier start of the Main Pollen Season (MPS) is proved for Rumex and Poaceae. APIn for 24 taxa shows a significant positive correlation with annual T min (< 0.005) and T mean (< 0.001), both of which showing a significant increase, and a negative correlation (< 0.025) with the number of frost days. From a human health perspective, higher temperatures, driven by climate changes, lead to higher concentrations of allergenic airborne pollen, turning into a higher risk for allergy sufferers.

The history of Fagus sylvatica at its northern limit in Vendsyssel, Denmark

Pollen, plant macrofossils and charcoal analyses were used to study tree diversity, fire history and forest disturbance over the past c. 3500 years at three forest remnant sites in Vendsyssel, northern Denmark. All locations had a more diverse tree composition in the past including abundant Alnus, Betula, Corylus, Pinus, Quercus, Salix, Tilia and Ulmus. The changes in tree diversity through time can be attributed to a combination of factors including climate change, burning linked to shifting cultivation, grazing and felling. The balance between arboreal and non-arboreal pollen was already being influenced by human activities in the late Bronze Age c. 3000 years ago. The high pollen abundance values recorded for Tilia pre-2000 years ago are exceptional as compared to later periods at these sites. At one location, the transition from Tilia to Fagus indicated that Tilia prevailed until c. 1300 years ago. Subsequent periods of forest clearance, with charcoal and cereal cultivation, initially including Hordeum and subsequently also Secale, were recorded. There was pollen evidence for grazing followed by shrub regeneration including Calluna, Erica, Juniperus and herbaceous taxa, and following that, a forest recovery of mainly Fagus, Picea and Pinus. This recovery is also recorded in historical forest records from 1880 CE onwards, emphasising the dominant role of plantation schemes. Results are placed in a wider framework of other sites in Denmark and southern Scandinavia, which have also documented a reduction of tree diversity and forest cover over the same period. The evidence from the long-term record is used to draw conclusions to assist forest restoration programmes.

First palynological results from Spila nad Procjepom cave, Mljet island (Croatia)

This paper presents the first results of palynological research from the Spila nad Procjepom cave, situated in the Mljet National Park, Croatia. The palynological data obtained, enables a partial insight into the local vegetation cover, temporal changes in the vegetation during the accumulation of studied deposits (at ca. 3500 cal years BP), and post-depositional processes that influenced the palynomorph assemblage. Results of palynofacies analysis indicate changes from fluvial (channel deposits), through palustrine to terrestrial environments. Although the interpretation of changes in plant cover, due to the lack of statistical significance, should be taken with caution, preserved pollen types confirm the dominance of the Mediterranean evergreen forest vegetation on Mljet island. Moreover, a high proportion of non-arboreal pollen (NAP) indicates some level of forest degradation, ranging from Mediterranean open forest to degraded maquis. Abundant charcoal additionaly confirms that the cave was inhabited by humans.

Early onset of aridity in the past millennium: Insights from vegetation dynamics and climate change in the alpine, cold-desert region of Trans Himalaya, India.

Palynological analysis of surface soil and sub-surface sediments from the outwash plain of Hamtah Glacier, Lahaul-Spiti, India, has brought out the vegetation and climatic changes in the area during the last 1580 years. The arboreal and non-arboreal pollen ratio (AP/NAP) has been used to demarcate the different vegetation and climatic zones, complemented by the frequencies of the broad-leaved taxa. Lower values of thermophilous, broad-leaved arboreal taxa, indicate that the region experienced cold-arid conditions between 1580 and 1330 yr BP (AD 370-620); which can be related to the Dark Ages Cold Period (DACP). Thereafter, between 1330 and 950 yr BP (AD 620-1000), a rejuvenation of the broad-leaved elements reflects the initiation of a comparatively warm and moist phase, marking the Medieval Climatic Anomaly (MCA) in the region. The warm-moist phase was, however, short-lived, and from 950 yr BP to the Present (AD 1000 onwards), the region saw a return to cold-arid conditions, as evidenced by a sharp fall in the AP/NAP ratio. This cold-arid phase was, nevertheless, punctuated by a warm-moist period during 790 to 680 yr BP (AD 1160-1270), which marks the terminal phase of the MCA. After the termination of the MCA, the Little Ice Age (LIA) is well-marked in the area. The culmination of the long cold-arid regime is characterized by warmer conditions over the last 160 years, which is the manifestation of the Current Warm Period (CWP). Magnetic susceptibility (χlf) and sediment geochemistry (Weathering Index of Parker) were also attempted to have a multi-proxy approach, and show a general compatibility with the palynological data. The palaeoclimatic evidences suggest shorter warm periods and extended colder phases during the last 1580 years; in this high-altitude, cold-desert, Trans Himalayan region.

The vegetation history of Lake Gâvur and surrounding areas during the last 4400 years (Kahramanmaraş, Türkiye)

This study discusses the paleovegetation records of shallow core sediments of Lake Gâvur (Kahramanmaraş, Türkiye), which was dried in the 1970s. A 5 m-long sediment core was obtained with an Eijkelkamp sediment sampler and palynological samples were taken at 10 cm intervals. The sediments were dated by AMS radiocarbon dating of bulk at two levels. Among arboreal pollen (AP) from approximately 4400 cal yr BC, the dominant tree taxa were Pinus, Cedrus, Quercus, and Fraxinus. Initially, AP dominated NAP (non-arboreal pollen) along with the pollen diagram, and AP gradually decreased up to the present. The evaluation of the fossil pollen percentage indicates that in that period arboreal taxa were more widely distributed around the lake than they are in the present. Inferred major causes for the increase of pollen percentage of Poaceae and Asteraceae in the LG-3 (upper) zone of the pollen diagram are anthropogenic impacts.

Modern pollen–vegetation relationship from the Mahasamund District (Chhattisgarh), central India: implications for palaeoecological reconstruction

The study of modern pollen–vegetation relationship is crucial for the proper interpretation of fossil pollen records. In the present study, a total of 29 surface samples, collected from the edge of the forested areas of the Mahasamund District, Chhattisgarh State, central India, were palynologically analysed with the principal aims of evaluating the modern pollen assemblages and understanding the modern pollen and extant vegetation relationship. The study reveals the dominance of non-arboreal pollen (NAP) taxa over the arboreal pollen (AP) taxa, suggesting open mixed tropical deciduous forest type vegetation in and around the study area. The tree taxa, on the whole, constitute an average sum of 19.78% pollen of the total pollen sum, whereas the contribution of herbs is 43.58% pollen (average sum). The major non-arboreal taxa are Cerealia/Cereal Poaceae (average value; 5.45% pollen) and Poaceae (average value; 4.34%), whereas the cultural plant pollen taxa, such as Amaranthaceae, Caryophyllaceae, Brassicaceae, Cannabis sativa, Alternanthera, and Borreria contribute with an average sum of 11.69% pollen to the total pollen sum. Most of the common forest elements are not recorded because they are insect-pollinated or have low pollen preservation potential, and, hence, the modern pollen assemblages do not directly reflect the actual extant vegetation occupying the landscape of the study area. This bias would also be expected in late Quaternary pollen records of central India and, hence, can provide information of the actual vegetation when analysing fossil pollen samples.

Recent pollen spectra from Shimla water catchment sanctuary, Kufri (HP): Implications to interpret Holocene pollen records

A better understanding on the connection between pollen assemblages and the vegetation that produced them is crucial to reconstruct past habitats and vegetation. Hence, it is necessary to comprehend the level of representation of plants in the modern pollen rain in a given study area. To ascertain the composition of pollen deposited on the surface sediments, palynological analysis of 19 surface soil (SS) samples and moss cushions (MSs) taken from various sites on the surface of the Shimla Water Catchment Wildlife Sanctuary (SWCWS), Kufri, Himachal Pradesh (India) was used in the current study. The dominance of arboreal pollen (trees and shrubs) over the non-arboreal pollen (herbs) was observed. Among the trees, conifers such as Cedrus deodara, Pinus wallichiana, Picea smithiana and Abies pindrow were found in MSs as well as in SS samples. The representation of these taxa corresponds with their factual presence in the forest floristics in the region. The moist and shady habitats loving broad-leaved tree elements such as Quercus and Rhododendron were also found in good numbers. Two multivariate statistical methods, cluster analysis and principal components analysis, were used to study the associations of studies pollen taxa and the variability among them. All the 19 samples were clustered into four. This analysis will help to interpret the palaeodata whether the landscape was influenced by anthropogenic activities or not in the recent past.

Plant remains preserved in products of metal corrosion: source of evidence on ancient plant materials and environment from burial contexts

By-products of metal corrosion, when coming into contact with organic matter, have the capacity to preserve it from decay. A pilot study was conducted aiming to explore the potential and limitations of plant remains preserved in by-products of metal corrosion for archaeobotanical research. The organic remains considered come from the surface/immediate proximity of the metal funerary artefacts of two ancient cemeteries—Varna and Messambria, Eastern Bulgaria. Metal corrosion by-products were observed and sampled, under a low magnification stereo microscope. Subsequently, the plant macrofossils recognised were analysed under reflected light and a scanning electron microscope (SEM). Additionally, pollen was extracted from the metal corrosion by-products, using standard acetolysis. The analyses from the graves of both cemeteries allowed identification of textiles and plant fibres, as well as wood (Cornus sp., Pinus sp., Viburnum sp.). At Varna cemetery epidermis fragments of Juncus sp. were recognized, while at Messambria necropolis fruits of almond were found. The pollen analysis from Varna points to use of flowers in the ritual (Daphne tetrads were recorded) and shows a notably open landscape with 77% non-arboreal pollen (NAP). The palynological analysis from the Messambria necropolis revealed the use of flowers in the burial ritual indicated by clusters of Vitis, Cistus and Rosaceae pollen. The surrounding vegetation was dominated by open oak woodland and open habitats (43% NAP) with a strong presence of anthropogenic indicators. The outcome of the study proved to be promising for reconstructing details of the burial rituals including associated plant materials, as well as the surrounding plant habitats during the functioning of the cemeteries.

Spatial influence of the Asian Summer Monsoon on pollen assemblages of the Tibetan Plateau and its potential implication for the interpretation of fossil pollen records

The direction and intensity of Asian Summer Monsoon (ASM) circulation in the Tibetan Plateau (TP) region strongly influence pollen dispersal patterns; however, this spatial effect has been rarely quantified. In this paper, we explore the relative importance of this directional spatial effect. Specifically, we construct a wind connectivity diagram for modern pollen sample sites according to the prevailing monsoon direction, and extract latent spatial variables representing the directional process of the ASM, using the method of asymmetric eigenvector maps. We fit redundancy analysis models using both spatial variables and local climate factors, and conduct variation partitioning to quantify the effect of directional spatial effect by the ASM. Taking into account the joint effect with local climate, the directional spatial process induced by the ASM significantly explains the variation of pollen assemblages on the TP. The effect is detected in pollen groups with contrasting functional types and dispersal modes; for example, the composition of arboreal pollen and non-arboreal pollen are both significantly affected by the ASM, yet best explained by models assuming different monsoon directions. Anemophilous pollen shows a higher percentage of variation explained by the ASM than non-anemophilous pollen. Our results indicate that directional processes induced by the monsoon is an important influence on pollen assemblages in the TP and support the idea that deposition patterns of pollen, especially arboreal pollen is a useful proxy for studying monsoon evolution. A similar approach can also be applied to paleomonsoon simulations using fossil pollen records. The role of directional dispersal in affecting fossil pollen composition and abundance by prevailing winds deserves further investigation when undertaking Quaternary paleoenvironmental reconstructions using pollen.

Postglacial vegetation and fire history with a high-resolution analysis of tephra impacts, High Cascade Range, Oregon, USA

The postglacial history of vegetation, wildfire, and climate in the Cascade Range (Oregon) is only partly understood. This study uses high-resolution macroscopic charcoal and pollen analysis from a 13-m, 14,500 years sediment record from Gold Lake, located in a montane forest, to reconstruct forest vegetation and fire history. The occurrence of three tephra layers, including a 78-cm airfall Mazama tephra, as well as highly laminated segments, allows one to study tephra impacts on vegetation at a fine temporal resolution. From the Late Glacial through the Younger Dryas, pollen spectra vary little. The early Holocene is marked by a sudden increase in Pseudotsuga, indicating warmer conditions, while the late Holocene is marked by increasing Tsuga heterophylla and Tsuga mertensiana, indicating the onset of moist conditions in the region. High-resolution charcoal data show periods of large peaks during the Late Glacial, pre-, and post-Mazama eruption and since 4 ka (thousands of years before present). Low fire during the early Holocene is unexpected, given regional evidence of warmer and drier summers, but it may be the result of fuel limitation. After the Mazama tephra deposition (7.63 ka), the non-arboreal pollen composition was changed, with some taxa disappearing or reduced in abundance for 300 years. Arboreal taxa were little affected by the tephra, showing only a 20% increase in Pinus pollen and no discernible impact on the pollen accumulation rate (PAR).In contrast, the Mazama tephra was followed by ca. 70 years of very low charcoal input, followed by a large peak, consistent with the burial of surface fuels and decades of fuel accumulation. There was also increased fire frequency and peak magnitude at 1.5 ka, followed by very little fire after 0.4 ka, consistent with the current old-growth forest surrounding the lake. This detailed and high-resolution record adds significantly to understanding the impacts of climate change and the singular effect of the Mazama eruption, impacting watershed vegetation, and fire for centuries but with minimal impact on the regional forest composition.

The diversity of flora at the Late Pliocene era in the Cisubuh Formation based on palynological data

Palynological evidence on past time gives features on plant diversity. The objective of this research was to determine the flora diversity in the past based on the palynological evidence in the form of pollen and spores (palynomorphs) that stored in sediments in the Cisubuh Formation. This research consisted of two stages, field sampling, and laboratory observation. A total of 16 samples on Cisubuh Formation on Rengasdengklok area, West Java Indonesia have been identified for their fossil content. Sixty-seven palynomorphs have been identified, comprised of 53 pollen taxa and 14 type of spores. Of the 67 palynomorph taxa, 40 were arboreal pollen, 12 were non-arboreal pollen, and 15 were Pteridophytes. The geological age of Cisubuh Formation was Late Pliocene, as indicated by Dacrycarpidites australiensis and without the presence of Stenochlaenidites papuanus. Based on the palynological evidence, the flora diversity in each layer sediment of the Cisubuh Formation showed high similarity (87%).

Holocene vegetation history and responses to climate and sea-level change in the Liaohe Delta, northeast China

To reconstruct the Holocene vegetation history from Liaohe Delta in northeast (NE) China, a high-resolution palynological study on a well-dated sediment core ZK2 was conducted. The pollen record of ZK2 suggests that during the early Holocene, the regional vegetation in the plain was meadow-dominated by Artemisia. And forest with cool-temperate conifers and temperate broad-leaved trees were present in the nearby hills, which is coincident with the gradual climate warming and delta transgression. From mid-Holocene to early late Holocene, meadow vegetation with Artemisia was relatively stable, while the forest vegetation with broadleaved trees reached the maximum expansion in the nearby hills. The large expansion of broadleaved trees indicates warm and humid regional environmental conditions and this is coincidental with the relatively high regional sea-level stand during this period. Since ca. 1470 cal yr BP, with the continuous delta progradation, a large coastal region was colonized by Suaeda spp., which suggests that the formation of unique red beach wetlands along the coastal region of the Liaohe Delta. By analysis of pollen dispersal and transportation mechanism in surface sediments of Liaodong Bay, it is indicated that the percentage changes of arboreal pollen dominated by Pinus and Quercus and the non-arboreal pollen dominated by Amaranthaceae and Artemisia in core ZK2 may as an index refers to the local sea level oscillation and paleoclimate change. Then by comparison with previous multi-proxy records together with the surface sediment record from Liaodong Bay, it is suggested that the Holocene vegetation changes of the Liaohe Delta are mainly driven by the intensity changes of East Asia monsoon and regional sea-level oscillation.

Modern pollen-vegetation relationship from the Rourkela (Sundargarh District), Odisha, India: a preliminary study and a comparative account

Vegetation reconstruction from fossil pollen records depends on an adequate understanding of the relationship between modern pollen-rain and the extant vegetation. Modern pollen assemblages, that reflect the extant vegetation of an area, have been documented through the palynological analysis of 30 modern moss cushions from Rourkela, Sundargarh District (Odisha State), India. The study demonstrated the dominance of non-arboreal pollen taxa (NAPs; herbs) over the arboreal pollen taxa (APs; trees and shrubs). Tree pollen taxa, among the APs, contributed with an average sum of 23% of the total pollen sum, whereas shrubby taxa have an average pollen sum of 17%. Among the herbs (NAPs), Poaceae is the dominating herbaceous taxon in the total pollen-rain, whereas Cerealia and other cultural pollen taxa are the other prominent herbaceous taxa of the pollen-rain, besides Asteroideae. The overall pollen assemblages suggest an open nature of the forest around the study area. Insights into pollen source, representation (production and dispersal), transport and preservation of certain taxa around the study area have been also provided. Comparison of the pollen assemblages in present study with the pollen assemblages from other areas (especially from central India) has been also been made in order to have a broad overview of such study around the study area. The present study could improve our understanding of the modern pollen-rain/vegetation relationship and further aid in calibration and interpretation of the fossil pollen records.

Airborne pollen can affect the abundance of predatory mites in vineyards: implications for conservation biological control strategies.

BACKGROUNDThe importance of pollen as alternative food for generalist phytoseiid mites occurring in vineyards has been investigated in northeastern Italy. We compared pollen and phytoseiid abundance in four vineyards and in plots located at different distance from flowering hop plants. Pollen (Carpinus betulus and Typha spp.) was sprayed onto the foliage to evaluate the potential impact of this food source on predatory mite abundance. Finally, grass management was investigated to analyze the effect of a reduced mowing frequency on predatory mite population densities.RESULTSArboreal pollen was found mostly during the spring and the grapevine blossoming period. Nonarboreal pollen dominated throughout the growing seasons. In vineyards, the abundance of Amblyseius andersoni, Kampimodromus aberrans, Phytoseius finitimus, Typhlodromus pyri eggs and motile forms increased after a phase of large pollen availability. Hop pollen promoted K. aberrans population increases in vineyards. Pollen applications increased predatory mite egg and motile form densities and similar effects were obtained by reducing mowing frequency in vineyards.CONCLUSIONPollen availability positively affects the biology of four phytoseiid species, promoting stable predatory mite populations in vineyards. However, natural pollen availability and predatory mite abundance often decrease in summer, and pollen supply can mitigate this trend. A higher pollen availability could be guaranteed by inserting hedges comprising species having scalar bloom, reducing mowing of inter‐row groundcover and spraying pollen. The presence of flowering plants surrounding vineyards and in their inter‐rows should be considered as a relevant factor to enhance the success of biocontrol tactics against phytophagous mites in viticulture.

Charcoal morphotypes and potential fuel types from a Mexican lake during MIS 5a and MIS 3

Charcoal particles vary in size and form, but they can preserve morphological characteristics used to infer the type of vegetation being burnt. To deduce potential fuel and fire type, we reconstructed local fire activity analyzing macrocharcoal morphologies and pollen data of the sediment core CHA08-V from Lake Chalco from the sub-stage MIS 5a to MIS 3, with CHAR data and Z-Score analysis. We identified the following fuel types: i) wood, characterized by blocky and quadrilateral morphologies with solid, foliated or striated surface textures; ii) grass, represented by rectangular-porous and rectangular-latticed morphologies; and iii) herbs, characterized by long-thin filaments and polygonal porous particles. Arboreal pollen components were associated to wood morphotypes whereas non-arboreal pollen related to herbs and grass morphotypes, indicating that variation in vegetation composition was important regulating factor determining fire types in the Basin of Mexico. This study provides the first long-term record of charcoal morphotypes for Mexico region to emphasize the importance of charcoal morphotypes analyses to complement paleoenvironmental interpretation of past fire regimes.

Modern pollen–climate relationships and their application for pollen-based quantitative climate reconstruction of the mid-Holocene on the southern Korean Peninsula

A modern pollen dataset is a prerequisite for reconstructing quantitative paleoclimate and paleovegetation cover using fossil pollen records. Although multiple modern pollen–climate datasets have been established covering a wide range of climate conditions, such datasets are exceedingly rare for the Korean Peninsula (KP). In this study, we acquired a modern pollen dataset from 198 surface soil samples collected on 37 mountains on the southern KP. Redundancy analysis (RDA) and variation partitioning results identified mean annual temperature (Tann) as the most important climate variable shaping pollen assemblages on the southern KP. Using the pollen–climate relationships inferred from the RDA, we applied the Huisman–Olff–Fresco model and determined that arboreal pollen taxa responded sensitively to the climatic gradient, whereas non-arboreal pollen taxa did not. We applied weighted averaging–partial least squares (WA-PLS) and the modern analog technique (MAT) to the pollen dataset, and a comparison of the results showed that MAT performed better than WA-PLS. A transfer function was applied to fossil pollen records from the areas covered by our dataset; the results confirmed that annual precipitation (Pann) and Tann were modulated by different mechanisms, with Pann strongly affected by El Niño–Southern Oscillation-driven typhoons during the Holocene, whereas Tann was mainly influenced by the Tsushima Warm Current from 7500 to 5100 cal yr BP depending on Kuroshio Current inflow intensity, and subsequently followed by the East Asian winter monsoon during 5100–3400 cal yr BP.