Journal articles: 'Pollen surface samples'

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Paudayal, Khum N., and Ishan Gautam. "Scanning Electron Microscopic Studies on Surface Pattern of the Pollen Loads from Apis cerana in Jajarkot District." Nepal Journal of Science and Technology 12 (July 23, 2012): 340–49. http://dx.doi.org/10.3126/njst.v12i0.6522.

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Over nineteen species of pollen flora belonging to thirteen families were recovered from four pollen load samples from honey bee Apis cerana collected in Jajarkot district, mid-western region, Nepal. The pollen morphology was investigated using light microscopy along with scanning electron microscopy for correct identification of pollen to its lower taxonomic level and to contribute to melissopalynological studies originating from the native apiflora. The palynological assemblage identified to the generic and some up to species level belong to Alnus sp., Artemisia sp., Brassica sp., Cornus sp., Diploknema sp., Fraxinus sp., Ilex sp., Jasminum sp., Justicia sp., Ligustrum sp., Myrica esculenta, Salix sp., Strobilanthes sp., and Urtica sp. Some of the pollen grains identified to only family level, belong to, Acanthanceae, Compositae, Lamiaceae and Rosaceae. The identified pollens clearly reflect the botanical and geographical origins of the pollen load samples. Palynomorphological investigation included the description of pollen symmetry, polarity, ornamentation, aperture, shape and size. The results for the pollen assemblages and nectariferous plant sources of Jajarkot district are discussed.DOI: http://dx.doi.org/10.3126/njst.v12i0.6522 Nepal Journal of Science and Technology 12 (2011) 340-349

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Dzyuba, O. F. "Pollen from surface samples as an environmental indicator." Paleontological Journal 40, S5 (October 2006): S584—S589. http://dx.doi.org/10.1134/s0031030106110050.

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Quamar, Md Firoze, Biswajeet Thakur, Veeru Kant Singh, and Santosh Kumar Pandey. "Pollen heteromorphism in Schleichera Lour. (Sapindaceae), observed in surface soil samples from central India." Acta Palaeobotanica 61, no. 1 (June 2021): 32–41. http://dx.doi.org/10.35535/acpa-2021-0003.

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Angiosperms display striking variation of pollen morphological features within and between populations of the same species, as well as within individual plants. We describe and illustrate variation of pollen aperture number, which is called pollen heteromorphism, in Schleichera Lour. (Sapindaceae) from surface soil samples collected from central India, based on combined observations from light microscopy (LM) and confocal laser scanning microscopy (CLSM). Tri-zono-parasyncolporoidate pollen grains are, in general, known to occur in Schleichera Lour., but occasional tetra-zono-parasyncolporoidate pollen is also recorded, for the first time, from Chhattisgarh State, central India. Changes in ploidy level (diploidy/polyploidy), chromosome number, the C-value of DNA, completion of meiosis, as well as environmental factors and/or pollination ecology could be driving the occurrence of pollen heteromorphism. The present study could provide insights into the phylogeny and systematics, and has implications for pollen preservation as well.

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Balakauskas, Lauras, Justina Gaižutytė, Vaidotas Valskys, and Giedrė Vaikutienė. "Analysis of pollen across the surface sediments of Lake Imbradas, Lithuania." Quaternary Research 106 (September 30, 2021): 113–28. http://dx.doi.org/10.1017/qua.2021.51.

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AbstractIn conventional pollen analysis, usually one sediment core per basin is analyzed to reconstruct past environmental conditions. This approach does not consider spatial heterogeneity of pollen assemblages, and assumes that one analyzed location is representative of the whole basin. To improve the spatial resolution of fossil pollen studies, further knowledge of the factors influencing variations in pollen assemblages throughout a basin is needed. We examined the spatial heterogeneity of pollen assemblages from 45 lacustrine surface samples from a lake with relatively simple hydrology and compared this dense network of surface pollen samples with the Lithuanian State Forest Service arboreal vegetation database. Calculations of pollen productivity at different locations across the lake revealed variations in the behavior of a pollen-vegetation relationship model in different parts of the basin. Our findings suggest that the model underestimated pollen contributions from the lakeshore vegetation. We demonstrate that detailed investigations of surface pollen as a step prior to fossil pollen investigations can provide useful insights, including understanding the influence of sedimentation rate on modelling results and spatial variations in pollen composition, thus providing guidance for site selection for fossil pollen studies.

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Pellatt, Marlow G., Rolf W. Mathewes, and Ian R. Walker. "Pollen analysis and ordination of lake sediment-surface samples from coastal British Columbia, Canada." Canadian Journal of Botany 75, no. 5 (May 1, 1997): 799–814. http://dx.doi.org/10.1139/b97-090.

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Surficial sediment samples from 42 lakes, distributed from sea level to alpine elevations of coastal British Columbia and northwest Washington, were analyzed for pollen and spores. Pollen analysis revealed characteristic differences among the assemblages of the Coastal Western Hemlock, Mountain Hemlock, and Engelmann Spruce – Subalpine Fir biogeoclimatic zones (the Alpine zone is less clearly identifiable). Cluster analysis and detrended correspondence analysis (DCA) correctly group the sites according to their biogeoclimatic zones and also by geographic origin. DCA indicates a high correlation between the biogeoclimatic zones of the sample sites and annual precipitation (−0.89), January temperature (−0.77), annual temperature (−0.64), and growing-season precipitation (−0.68). Further analysis of the samples and eight environmental gradients using canonical correspondence analysis groups the pollen assemblages from the study sites into biogeoclimatic zones in relation to annual precipitation, growing-season precipitation, annual snowfall, annual temperature, and growing degree-days. These data are useful for testing whether or not postglacial pollen assemblages have modern analogues. Key words: modern pollen analysis, vegetation, ordination, multivariate statistical analysis, biogeoclimatic zones, British Columbia.

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King, George A. "Vegetation and pollen relationships in eastern Canada." Canadian Journal of Botany 71, no. 2 (February 1, 1993): 193–210. http://dx.doi.org/10.1139/b93-022.

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The relationship between the vegetation and modern pollen assemblages in eastern Canada is summarized and analyzed using isopoll maps, ordination, and cluster analysis. The major vegetation zones are shrub tundra, forest tundra (divided into shrub and forest subzones), lichen woodland, closed black spruce forest, mixed boreal forest, and coastal barrens. The pollen assemblages of these zones are distinguished by differences in the relative abundance of a few important pollen types rather than by floristic differences. Northern zones have relatively high Cyperaceae and low Picea pollen percentages, and southern zones have high Picea and Abies pollen percentages. Surface samples from each vegetation zone generally form distinctive groups in the ordination analysis. However, samples from the shrub subzone of the forest tundra cluster with shrub tundra samples, and lichen woodland samples cluster with samples from the closed black spruce forest and the forest subzone of the forest tundra. Cluster analysis separates the samples into geographically distinct groups. However, these groups generally contain samples from several vegetation zones. The surface sample data set analyzed here will prove useful in reconstructing the vegetation history of the region. Key words: pollen surface samples, modern vegetation, eastern Canada.

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Bunting, M. Jane, Barry G. Warner, and Clayton R. Morgan. "Interpreting pollen diagrams from wetlands: pollen representation in surface samples from Oil Well Bog, southern Ontario." Canadian Journal of Botany 76, no. 10 (October 1, 1998): 1780–97. http://dx.doi.org/10.1139/b98-158.

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Pollen and spore analysis of surface sediment samples from 45 points within Oil Well Bog, a coniferous swamp near Cambridge, Ontario, was used to determine the possibility of identifying different wetland vegetation communities from their palynological record, and to assess the effects of variable wetland vegetation on the pollen representation of surrounding upland communities. The data obtained were mapped for individual taxa to allow direct comparison of the spatial patterns of vegetation abundance and the associated palynological assemblages, and cluster analysis was used to identify palynologically similar assemblages. Some wetland communities, such as swamp dominated by black spruce, do have distinctive pollen signatures, but not all the vegetational diversity observed is reflected in the palynological data, with similar pollen assemblages deriving from some communities which are vegetationally very different (e.g., shrub swamps dominated by Chamaedaphne calyculata and Ilex verticillata). The wetland pollen assemblages do reflect much of the floristic diversity of the surrounding uplands, although the different communities receive varying proportions of their pollen influx from upland sources (varying from less than 5% to over 90%), and wide variations in the percentage of a given upland pollen morphotype can be found within quite a short distance, depending on the nature of local wetland communities.Key words: palynology, swamp, surface samples, wetland.

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Bunting, M. Jane, Barry G. Warner, and Clayton R. Morgan. "Interpreting pollen diagrams from wetlands: pollen representation in surface samples from Oil Well Bog, southern Ontario." Canadian Journal of Botany 76, no. 10 (1998): 1780–97. http://dx.doi.org/10.1139/cjb-76-10-1780.

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Isik, Ayla, Murat Ozdemir, and Ibrahim Doymaz. "Infrared drying of bee pollen: effects and impacts on food components." Czech Journal of Food Sciences 37, No. 1 (March 6, 2019): 69–74. http://dx.doi.org/10.17221/410/2017-cjfs.

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Infrared radiation drying being one of the innovative drying methods was chosen to perform comparative study at different infrared power levels at 50, 62, 74 and 88 W. Quality attributes such as protein, fat, ash, carbohydrate, vitamin C content, solubility index and colour of infrared dried bee pollen samples were evaluated. The infrared power has a significant effect on the drying and quality characteristics especially colour. Drying time was reduced from 170 to 50 min when the infrared power level increased from 50 W to 88 W. Morphological changes on the surface of bee pollen grains increased with increasing the infrared power. The bee pollen infrared dried at 50 W retained its quality characteristics better than the bee pollens infrared dried at other power levels.

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Clayden, S. L., L. C. Cwynar, and G. M. MacDonald. "Stomate and pollen content of lake surface sediments from across the tree line on the Taimyr Peninsula, Siberia." Canadian Journal of Botany 74, no. 7 (July 1, 1996): 1009–15. http://dx.doi.org/10.1139/b96-125.

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Surface-sediment samples from 23 lakes on the Taimyr Peninsula were collected along a transect from tundra to forest and analyzed for their pollen and coniferous stomate content. Larix sibirica, the dominant tree in forest–tundra and forest vegetation zones, is poorly represented in the pollen spectra, never exceeding 8%. To examine the correspondence between the modern pollen rain and the vegetation zones of tundra, forest–tundra, and forest, a principal components analysis was applied to the pollen percentages. Betula and Alnus account for the greatest variance in the data set, and the set of tundra sites farthest north is distinct from the forest sites farthest south. Stomates of L. sibirica are present in all samples from sites where Larix trees are present, and some samples contained higher concentrations of stomates than pollen of Larix. Picea obovata stomates are found less consistently and less abundantly than Larix stomates.

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Allen, Gregory B., Kendrick J. Brown, and Richard J. Hebda. "Surface pollen spectra from southern Vancouver Island, British Columbia, Canada." Canadian Journal of Botany 77, no. 6 (October 30, 1999): 786–99. http://dx.doi.org/10.1139/b99-038.

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Analyses of surface samples of 84 sites from southern Vancouver Island were used to characterize pollen and spore spectra of modern vegetation types. Xeric Quercus garryana Dougl. and grassland associations can be identified by Quercus pollen and abundant nonarboreal pollen, respectively. Coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) forests are distinguished by high proportions of Pseudotsuga and low Pseudotsuga to Tsuga heterophylla (Raf.) Sarg. ratios. Coastal Western Hemlock zone forests have abundant Tsuga heterophylla pollen. Dry Coastal Western Hemlock subzones have diagnostically abundant Pseudotsuga and Tsuga heterophylla pollen, and intermediate Pseudotsuga to Tsuga heterophylla ratios. Moist Coastal Western Hemlock variants are characterised by little or no Pseudotsuga pollen and high Pseudotsuga to Tsuga heterophylla ratios. The Mountain Hemlock zone exhibits abundant Tsuga mertensiana (Bong.) Carr. pollen percentages and notable nonarboreal pollen and spore values. Relatively high Alnus values are not necessarily indicators of dominant alder stands, especially when obtained from open communities. Pseudotsuga to Tsuga heterophylla ratios are useful as a proxy measure of mean annual precipitation between 700 and 2700 mm.Key words: pollen and spores, surface spectra, Vancouver Island, biogeoclimatic zone, vegetation, precipitation.

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Horrocks, Mark, Sally A. Coulson, and Kevan A. J. Walsh. "Forensic Palynology: Variation in the Pollen Content of Soil Surface Samples." Journal of Forensic Sciences 43, no. 2 (March 1, 1998): 16139J. http://dx.doi.org/10.1520/jfs16139j.

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Yang, Shixiong, Zhuo Zheng, Kangyou Huang, Yongqiang Zong, Jianhua Wang, Qinghai Xu, Barry V. Rolett, and Jie Li. "Modern pollen assemblages from cultivated rice fields and rice pollen morphology: Application to a study of ancient land use and agriculture in the Pearl River Delta, China." Holocene 22, no. 12 (July 6, 2012): 1393–404. http://dx.doi.org/10.1177/0959683612449761.

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Pollen from a series of surface soil samples collected along a transect spanning southeast China was investigated to better understand palynological signals of ancient agriculture and other human activity. The transect surface samples consist of pairs taken inside and outside rice paddy fields. Pollen assemblages from these samples are valuable as modern analogs of human-altered environments and rice agriculture. Our measurements of Poaceae pollen grains from inside the modern rice fields discovered that 34–40 µm is the statistically significant size range for identifying domesticated rice in fossil pollen samples. This conclusion is also based on a size comparison of raw and chemically treated modern pollen grains from the plants. Pollen measurements for local wild grasses show that most native weeds have pollen grains less than 30 µm in size. The modern analogs and our study of the influence of chemical treatment on pollen grain size made it possible to examine a sediment core from the Pearl River delta for evidence of anthropogenic influence, including rice farming. Pollen assemblages from around 2200 cal. yr BP are highly similar to those of our modern analogs representing disturbed landscapes outside modern rice fields. The pollen spectra reveal abrupt increases in Poaceae, Dicranopteris, Artemisia and Pinus indicative of rice farming and forest clearance, at around 2200 cal. yr BP. Major factors associated with this abrupt transition were the rapid formation of the deltaic flood plain and massive increases in the Pearl River delta area population during the Qin Dynasty.

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Hagemans, Kimberley, Claudia-Dana Tóth, Manuela Ormaza, William D. Gosling, Dunia H. Urrego, Susana León-Yánez, Friederike Wagner-Cremer, and Timme H. Donders. "Modern pollen-vegetation relationships along a steep temperature gradient in the Tropical Andes of Ecuador." Quaternary Research 92, no. 1 (March 15, 2019): 1–13. http://dx.doi.org/10.1017/qua.2019.4.

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AbstractThe characterization of modern pollen rain assemblages along environmental gradients is an essential prerequisite for reliable interpretations of fossil pollen records. In this study, we identify pollen-vegetation relationships using modern pollen rain assemblages in moss polsters (n = 13) and lake sediment surface samples (n = 11) along a steep temperature gradient of 7°C (3100–4200 m above sea level) on the western Andean Cordillera, Ecuador. The pollen rain is correlated to vascular plant abundance data recorded in vegetation relevées (n = 13). Results show that pollen spectra from both moss polsters and sediment surface samples reflect changes in species composition along the temperature gradient, despite overrepresentation of upper montane forest taxa in the latter. Estimated pollen transport distance for a lake (Laguna Llaviucu) situated in a steep upper montane forest valley is 1–2 km, while a lake (Laguna Pallcacocha) in the páramo captures pollen input from a distance of up to 10–40 km. Weinmannia spp., Podocarpus spp., and Hedyosmum sp. are indicators of local upper montane forest vegetation, while Phlegmariurus spp. and Plantago spp. are indicators for local páramo vegetation.

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de Porras, María Eugenia, Antonio Maldonado, Andrés Zamora-Allendes, and Claudio Latorre. "Calibrating the pollen signal in modern rodent middens from northern Chile to improve the interpretation of the late Quaternary midden record." Quaternary Research 84, no. 3 (November 2015): 301–11. http://dx.doi.org/10.1016/j.yqres.2015.10.004.

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The use of rodent middens from northern Chile as paleoecological archives has at times been questioned due to concerns about their biogenic origin and the degree to which their record represents vegetation composition rather than rodent habits. To address such concerns, we carried out a modern calibration study to assess the representation of vegetation by pollen records from rodent middens. We compared vegetation censuses with soil-surface and midden (matrix and feces) pollen samples from sites between 21° and 28°S. The results show that (1) the pollen signal from the midden matrix provides a more realistic reflection of local vegetation than soil-surface samples due to the pollen-deposition processes that occur in middens; and (2) in contrast to feces pollen assemblages, which feature some biases, rodent dietary habits do not seem to influence midden matrix pollen assemblages, probably because midden agents are dietary generalists. Our finding that modern pollen data from rodent middens reflect vegetation patterns confirms the reliability of midden pollen records as paleoecological archives in northern Chile.

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Jantz, Nele, Jürgen Homeier, Susana León-Yánez, Alejandra Moscoso, and Hermann Behling. "Trapping pollen in the tropics — Comparing modern pollen rain spectra of different pollen traps and surface samples across Andean vegetation zones." Review of Palaeobotany and Palynology 193 (June 2013): 57–69. http://dx.doi.org/10.1016/j.revpalbo.2013.01.011.

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Elliot-Fisk, D. L., J. T. Andrews, S. K. Short, and W. N. Mode. "Isopoll Maps and an Analysis of the Distribution of the Modern Pollen Rain, Eastern and Central Northern Canada." Géographie physique et Quaternaire 36, no. 1-2 (November 29, 2007): 91–108. http://dx.doi.org/10.7202/032471ar.

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ABSTRACT At 39 sites in eastern and central northern Canada, multiple samples of surface moss and lichens have been analyzed for their pollen content. Although pollen from 20 to 30 taxa were identified in the samples from each site, 8 pollen types (Alnus, Betula, Picea. Pinus, Salix, Gramineae, Cyperaceae and Ericaceae) usually comprise 90 to 100% of the pollen rain. We present isopoll maps of these taxa based on mean percentages of multiple samples from the 39 sites. The data are further analyzed by a number of statistical methods to determine whether there are specific pollen assemblages within this region and to what extent present day climatic parameters and floristic/vegetation zones correlate with pollen counts. Cluster analysis on raw data and on principal component scores yields six distinct pollen assemblages which are further examined by discriminant analysis. Pollen concentration maps for eastern Canada are also presented here and used as an aid in interpreting the percentage data.

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Furlanetto, Giulia, Cesare Ravazzi, Federica Badino, Michele Brunetti, Elena Champvillair, and Valter Maggi. "Elevational transects of modern pollen samples: Site-specific temperatures as a tool for palaeoclimate reconstructions in the Alps." Holocene 29, no. 2 (November 19, 2018): 271–86. http://dx.doi.org/10.1177/0959683618810395.

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The potential of quantitatively reconstructing climate from modern pollen assemblages from high mountain environments has been widely debated but seldom tested. We analysed the pollen deposition in 53 surface samples (mosses) in relation to July temperature in two elevational transects in the European Alps. Each surface-sample site was assigned climate data derived from the local-scale climate. We compared our results with a larger calibration set extracted from the European Modern Pollen Database (EMPD) and centred on the European Alps. This also was assigned local climate data. The main calibration set (234 pollen samples) had Alnus harmonized at genus level; in contrast, a second set was selected (174) that retained the taxonomic resolution of Alnus viridis, which is one of the main climate indicators in the timberline ecotone. The overall and individual pollen responses to July temperature were inferred by canonical correspondence analysis (CCA), generalized linear regression (eHOF) and weighted averaging (WA). Quantitative climate reconstructions for each sample site of the two elevational transects were obtained using transfer functions, that is, WA and WA partial least squares (WA-PLS) regressions. In each calibration set, around 30% of the pollen taxa show a relationship with July temperature through monotonic or unimodal functions. The best transfer function obtained has a good statistical performance, with a determination coefficient ( r2) of 0.74. We propose new calibration procedures formulated to include the full climate space of the modelled taxa, as well as to account for uphill pollen transport in the high mountains and for human activity.

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Gupta, H. P., and R. R. Yadav. "History of mangrove vegetation in Paradip and Jambu islands, Orissa for the past 500 years B.P.: A palynological assessment." Journal of Palaeosciences 38 (December 31, 1989): 359–69. http://dx.doi.org/10.54991/jop.1989.1671.

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Modern surface samples from Paradip and Jambu islands, Orissa have provided clues of modern pollen deposition, reconstruction of palaeovegetation and to interpret with greater precision the pollen data recovered from the sediments. Pollen composition of modern surface samples coheres with the type of vegetation growing today within the area of 10 sq km and facilitates the comparison of past vegetation with the modern analogues. Pollen diagram constructed from Paradip profile has revealed the history of mangrove vegetation for the past 500 years B.P., wherein four zones of vegetational developments have been recorded. The decline of mangrove vegetation at the top of the diagram going back to about 35 years B.P. could be correlated with a record date around early nineteen-hundred-sixties, when the construction of Paradip Port came into existence. This feature suggests the excessive human pressure over the surrounding vegetation resulting into the ruthless damages to the mangrove and the same has been depicted in the pollen diagram. The plantation of Casuarina along the coastline in the recent past has also been recorded in the pollen diagram.

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Marguier, S. "Modern pollen and plant macrofossil-vegetation relationships in lake sediment surface-samples." Review of Palaeobotany and Palynology 82, no. 1-2 (June 1994): 193. http://dx.doi.org/10.1016/0034-6667(94)90033-7.

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Hansen, Barbara C. S., Glen M. MacDonald, and Katrina A. Moser. "Identifying the tundra – forest border in the stomate record: an analysis of lake surface samples from the Yellowknife area, Northwest Territories, Canada." Canadian Journal of Botany 74, no. 5 (May 1, 1996): 796–800. http://dx.doi.org/10.1139/b96-099.

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Conifer stomata were identified in surface samples from lakes in the treeline zone near Yellowknife, Northwest Territories, to assess the potential use of fossil stomata for reconstructing past changes in the arctic tree line. Stomata of Larix, Pinus, Picea mariana, and Picea glauca were distinguished. Conifer stomata were absent in samples from tundra lakes, whereas they were generally present in forest–tundra and forest lakes. Stomate analysis recorded the presence of Larix trees in the area; in contrast, the pollen of this relatively common tree was infrequent in pollen surface samples from the same sites. Conifer stomate analysis, however, is not able to resolve differences between forest–tundra and closed forest. The potential of stomata for providing improved resolution of past locations of the tree line, coupled with the presence of stomata in lakes that would lack good macrofossil records, suggest that stomate analysis will become an important technique supplementing pollen analysis for reconstructing past tree-line changes. Keywords: Northwest Territories, conifer stomata and pollen, tree line, tundra, forest–tundra, closed forest.

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Vasil'chuk, Alla Constantinovna, and Yurij Kirillovich Vasil'chuk. "Pollen spectra of Polar Ural glaciers." Арктика и Антарктика, no. 4 (April 2020): 1–14. http://dx.doi.org/10.7256/2453-8922.2020.4.34641.

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The subject of this article is the pollen spectra of the samples from the surface of Romantic's Glacier, located in the Polar Urals in the Rai-Iz mountain range, as well as generalization of the results of published studies dedicated to glaciers of the Urals. The author also examines the pollen spectra of massive ice, which can be attributed to ice of atmospheric origin on the basis of similarity with the pollen spectra obtained from the surface of the glacier. The article reviews climatic peculiarities of the Polar Urals due to the existence of glaciers below the snow line, namely the landscapes of the Polar Urals, including vegetation as a source of pollen and spores falling onto the surface of glaciers of the Polar Urals, as well as possibility of distant pollen drift to the surface of Romantic’s Glacier. The main result consists in the conclusion that the composition pollen spectra of the Romantic’s Glacier in the Rai-Iz mountainous area is mainly determined by the long-range transport of pollen and spores from the western and south-western regions in a latitude direction. The pollen spectra obtained from the surface of the Romantic’s Glacier are characterized by significant presence of various pollen from broad-leaved rocks of lip, maple, oak, and hazel. Pine pollen and high forest birch are prevalent. Local vegetation is very poor. However, the pollen spectra indicates pollen of heath and crowfoot family, and grasses.

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Bush, Mark B. "Deriving Response Matrices from Central American Modern Pollen Rain." Quaternary Research 54, no. 1 (July 2000): 132–43. http://dx.doi.org/10.1006/qres.2000.2138.

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Modern pollen samples collected from 80 locations and representing a wide array of mature habitats in Panama and Costa Rica provide analogs to assist in the interpretation of fossil pollen records. Pollen spectra accurately reflect changes in actual forest types. Upslope transport of pollen of anemophilous species is evident in the sparsely vegetated montane samples. However, the corresponding downslope transport of these prolific pollen producers is masked by local pollen production. Mean pollen representation across gradients of mean annual temperature (MAT; 4°C increments) and mean annual precipitation (MAP; 500 mm increments) for 17 pollen types are presented as response matrices. Although preliminary in nature, these response matrices present a clearer image of pollen representation than can be obtained by considering gradients of MAT or MAP alone.

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Mehrotra, Nivedita, and Santosh K. Shah. "A preliminary study of the modern pollen of Tripura, Northeast India." Journal of Palaeosciences 67, no. (1-2) (December 31, 2018): 21–31. http://dx.doi.org/10.54991/jop.2018.45.

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The vegetation distribution in Tripura, Northeast India was studied from the modern pollen assemblages at various sites in the region. Sediment samples and moss cushions were collected along transects from North to South Tripura to assess the modern pollen taxa dominant in the region. A number of taxa showing a modern day distribution of moist deciduous mixed vegetation dominant in Tripura were observed in the modern pollen data. Statistical significance of the modern–pollen data was verified using one–way ANOVA technique. Despite the limited pollen taxa recorded in the surface samples the analysis proved the potential of the pollen data and scope for future palynological studies. The impact of anthropogenic activity is clearly visible through the low sample yield and presence of taxa such as Poaceae, Amaranthaceae, Solanaceae, etc. Other factors such as entomophilous tendency and/or low yield of pollen in tropical plants, excessive rainfall, sediment distribution and jhum cultivation could contribute to the lack of pollen preservation in the region.

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Senn, Carolina, Willy Tinner, Vivian A. Felde, Erika Gobet, Jacqueline FN van Leeuwen, and César Morales-Molino. "Modern pollen – vegetation – plant diversity relationships across large environmental gradients in northern Greece." Holocene 32, no. 3 (November 27, 2021): 159–73. http://dx.doi.org/10.1177/09596836211060494.

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Past vegetation and biodiversity dynamics, reconstructed using palaeoecological methods, can contribute to assessing the magnitude of the current biodiversity crisis and anticipating future risks and challenges. Among the different palaeoecological techniques, pollen analysis is probably the most widely used to reconstruct vegetation and plant diversity changes through time. Such reconstructions demand robust and comprehensive calibration studies addressing the pollen representation of extant vegetation to be sound. However, calibration studies are rare in the Mediterranean biodiversity hotspot, particularly regarding plant diversity. Here, we contribute to filling this gap by investigating the modern pollen signature of Mediterranean vegetation across a large environmental gradient in northern Greece. At each sampling site ( n = 61), we quantitatively compared the composition and diversity of plant (vegetation surveys) and pollen assemblages (moss/topsoil samples) using numerical techniques. Further, we compared these terrestrial pollen assemblages with those from lake sediment surface samples of the same region. We found an overall good match between plant and pollen assemblages, with maquis and mixed deciduous forest displaying particularly distinct pollen signatures. In contrast, the high regional importance of pines and oaks and their large pollen production blurred the pollen representation of other forested vegetation types and of shrublands and grasslands. Plant and pollen richness and their evenness showed similar declining trends with increasing altitude, but plant and pollen evenness bore a better match than richness. A more detailed vegetation-specific view on the data suggests that pine pollen seriously affected pollen richness and evenness in most of the pine-dominated stands. Lastly, our results suggest a rather straightforward application of vegetation-pollen relationships from moss/topsoil samples to interpret pollen assemblages from lakes in Mediterranean settings.

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Luz, Cynthia Fernandes Pinto da, Ortrud Monika Barth, and Cleverson Guisan Silva. "Spatial distribution of palynomorphs in the surface sediments of the Lagoa do Campelo lake, North region of Rio de Janeiro State, Brazil." Acta Botanica Brasilica 19, no. 4 (December 2005): 741–52. http://dx.doi.org/10.1590/s0102-33062005000400009.

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Four samples of the surface sediments of the Lagoa do Campelo lake bottom were collected in a transect of 500 m by 500 m from edge to edge, in a northeast/southwest direction, the dominant wind direction in the region. The analysis of pollen grains, fern spores and algae were used to evaluate their spatial deposition and level of deterioration. In total, 58 types of pollen grains were identified, mainly from herbs as Cyperaceae, Poaceae and Typhaceae. Pollen grains occurred in all the analyzed sediments. The area of highest concentration was the northeast side of the lake. The southwest side showed the highest pollen grain and fern spore degradation and mechanical damage, probably as they were carried across the lake by wind-driven currents, confirming the depositional tendency of damaged palynomorphs in the same direction as the dominant wind. Among the pollen of trees and shrubs, Alchornea, Arecaceae, Cecropia, Celtis, Clethra and Myrtaceae were dominant at more than 1,000 pollen grains per gram of sediment. The quantity of fern spores was practically constant in all samples (± 10% of the total of palynomorphs). The algae Pediastrum tetras (Ehrenberg) Ralfs and Mougeotia occurred in all samples, but Spirogyra only in three of them. The results obtained gave new information about the richness, concentration and distribution of palynomorphs in the lake, representing the local and regional vegetation.

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Stivrins, Normunds, Agrita Briede, Dace Steinberga, Nauris Jasiunas, Jurijs Jeskins, Laimdota Kalnina, Alekss Maksims, Zigmars Rendenieks, and Liva Trasune. "Natural and Human-Transformed Vegetation and Landscape Reflected by Modern Pollen Data in the Boreonemoral Zone of Northeastern Europe." Forests 12, no. 9 (August 28, 2021): 1166. http://dx.doi.org/10.3390/f12091166.

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Modern pollen composition obtained from waterbody surface sediment represents surrounding vegetation and landscape features. A lack of detailed information on modern pollen from Latvia potentially limits the strength of various pollen-based reconstructions (vegetation composition, climate, landscape, human impact) for this territory. The aim of this study is to compare how modern pollen from natural and human-made waterbodies reflects the actual vegetation composition and landscape characteristics. Modern pollen analyses from surface sediment samples of 36 waterbodies from Latvia alongside oceanic-continental, lowland-upland, urban-rural and forested-agricultural gradients have been studied. In addition, we considered the dominant Quaternary sediment, soil type and land use around the studied waterbodies in buffer zones with widths of one and four km. The information on climate for the last 30 years from the closest meteorological station for each study site was obtained. Data were analyzed using Pearson correlation and principal component analysis. Results show that relative pollen values from surface sediment of waterbodies reflect dominant vegetation type and land use. Modern forest biomass had a positive correlation with pollen accumulation rate, indicating the potential use of pollen-based forest biomass reconstructions for the boreonemoral zone after additional research and calibration.

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López-Sáez, José Antonio, Arthur Glais, Ioannis Tsiripidis, Spyros Tsiftsis, Daniel Sánchez-Mata, and Laurent Lespez. "Phytosociological and ecological discrimination of Mediterranean cypress ('Cupressus sempervirens') communities in Crete (Greece) by means of pollen analysis." Mediterranean Botany 40, no. 2 (September 26, 2019): 145–63. http://dx.doi.org/10.5209/mbot.59789.

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Sixty modern surface samples collected from mosses in different cypress forest communities (Cupressus sempervirens L.) on the island of Crete (Greece) were analysed for their pollen content. The samples were taken from six different cypress phytosociological associations between 23 and 1600 m asl, and fall within distinct rainfall and temperature regimes. The aims of this paper are to provide new data on the modern pollen rain from the Aegean islands, and to perform these data using multivariate statistics (hierarchical cluster analysis and canonical correspondence analysis) and pollen percentages. The discrimination of pollen assemblages corresponds to a large extent to the floristic differentiation of Cupressus sempervirens forest vegetation and indicates the existence of three new associations.

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Bera, S. K., and H. P. Gupta. "Correlation between pollen spectra and vegetation of Chhota Shigri Glacier in Himachal Pradesh, India." Journal of Palaeosciences 38 (December 31, 1989): 404–10. http://dx.doi.org/10.54991/jop.1989.1675.

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Pollen analysis of modern surface samples and glacial deposits, collected from Chhota Shigri Glacier at different altitudes ranging between 3.750 to 5.010 m, has been carried out to understand the pollen/vegetation relationship. The study reflects the predominance of extra-regional arboreals over local non-arboreal taxa.

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Ogden, Gordon J. "Pollen analysis: state of the art." Géographie physique et Quaternaire 31, no. 1-2 (December 9, 2010): 151–59. http://dx.doi.org/10.7202/1000061ar.

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Although nearly 50 years have passed since P.B. Sears introduced pollen analysis to North America, it remains an occult art. Dramatic improvements in sampling and analytic techniques continue to be limited by intractable problems of differential production, dispersal, ballistics, sedimentation, and preservation. It is a basic tenet of pollen stratigraphy that the data set, consisting primarily of microfossils preserved in sediments, is better than anything we have yet been able to do with it. Basic agreement between late- and postglacial pollen records has been confirmed wherever the method has been applied. Quantitative sampling techniques, sample preparation, and analytic procedures, together with multiple radiocarbon dates, permits calculation of sedimentation rates and absolute pollen influx. Of approximately 300 sediment cores from northeastern North America, fewer than 30 have more than 3 radiocarbon determinations from which least squares power curve regressions can be reliably calculated in the determination of sedimentation rates. Analogy with modern environments represented by surface pollen spectra is limited by an insufficient number of samples of uniform quality to characterize a vegetational mosaic covering 40 degrees of latitude (40-80°N) and longitude (60-100°W). The present surface pollen data bank includes about 700 samples, unevenly spaced and of uneven quality, permitting a grid resolution of no better than 10,000 km2.

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Wrońska-Pilarek, Dorota, Monika Dering, Jan Bocianowski, Kacper Lechowicz, Wojciech Kowalkowski, Władysław Barzdajn, and Maria Hauke-Kowalska. "Pollen Morphology and Variability of Abies alba Mill. Genotypes from South-Western Poland." Forests 11, no. 11 (October 22, 2020): 1125. http://dx.doi.org/10.3390/f11111125.

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The objective of this study was to investigate pollen morphology and ranges of intraspecific variability of Abies alba Mill. Pollen grains were collected from nine clonal seed orchards of A. alba in the Sudety Mountains, (South-Western Poland). At each seed orchard, 4–6 grafts were selected. Each individual (graft) was represented by 30 pollen grains and 1440 pollen grains were measured totally. Eight quantitative and four qualitative features of pollen grains were analysed. The diagnostic features of pollen grains for the studied species were: Exine surface of pollen corpus (cappa and leptoma) and sacci, the length of the polar axis (P), pollen shape (P/E ratio), and a new trait—saccus shape (A/B ratio — saccus width (A) to his length (B)). Pollen features made possible to differentiate seven individual genotypes (samples). To our knowledge, this is the first time that the intraspecific and interindividual variability of pollen grains of A. alba were investigated. The most different were the pollen grains from samples—genotypes 13 (Bystrzyca Kłodzka) and 18 (Jugów), and also (although to a lesser extent) genotypes—11 (Kamienna Góra), 30, 31 (Jugów), and 44 (Szklarska Poręba). No significant relationships were observed between the pollen grain traits and the geographical location of the collection sites.

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Nosova, Maria B., Elena E. Severova, Olga A. Volkova, and Jana V. Kosenko. "Representation of Picea pollen in modern and surface samples from Central European Russia." Vegetation History and Archaeobotany 24, no. 2 (August 20, 2014): 319–30. http://dx.doi.org/10.1007/s00334-014-0480-0.

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Quamar, M. F., and M. S. Chauhan. "Modern pollen assemblages from teak (Tectona grandis Linn. F.) dominated tropical deciduous forest in southwestern Madhya Pradesh, India." Journal of Palaeosciences 62, no. (1-2) (December 31, 2013): 29–37. http://dx.doi.org/10.54991/jop.2013.333.

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This paper gives an account on the modern pollen rain–vegetation relationships, based on the pollen analysis of 12 surface samples, 2 samples each collected from the southern, northern, eastern and western flanks of Amjhera Swamp as well as 4 from the mixed tropical deciduous forests dominated by teak (Tectona grandis) in Hoshangabad District, southwestern Madhya Pradesh, India. The pollen assemblages demonstrate the dominance of arboreals (trees and shrubs) over non–arboreals (herbs). Among the tree taxa, Madhuca indica is constantly represented with average pollen frequency of 37.36% in most of the samples which could be attributed to the good preservation of its pollen in the sediments coupled with its high pollen dispersal efficiency. Terminalia (av. 5.1%) is also retrieved steadily. However, Tectona grandis is untraced in the samples despite being an enormous pollen producer and dominant forest component, which could be due to its low pollen dispersal efficiency and differential pollen preservation. Besides, Adina cordifolia, Mitragyna parvifolia, Schleichera oleosa and Emblica officinalis are present with average pollen frequencies of 8.1%, 7.8%, 6.69% and 1.126%, respectively, but only in a few samples. Syzygium, Maytenus, Lagerstroemia, Lannea coromandelica, etc. are also intermittently recovered in almost all the samples, but in varying frequencies (< 0.5%–7.91%) despite their frequent presence in the forest. This erratic display of all these taxa could be inferred to their low pollen productivity, since majority of the tropical trees portray a strong tendency of entomophily. The partial preservation of their pollen in the sediments cannot also be denied. The relatively meagre representation of grasses, sedges, Malvaceae, Xanthium except Tubuliflorae and culture pollen taxa such as Cheno/Am, Caryophyllaceae, Brassicaceae and Cannabis sativa are suggestive of poor herbaceous cover around the swamp and also in the mixed tropical deciduous forest. However, the record of Cerealia and other culture pollen taxa stamps the proximity of cultivated land and human habitation in and around the investigation site. The abundance of trilete fern spore as well as Ceratopteris, monolete fern spore and trilete with perine, though in relatively low values envisages their origin from the local sources as ferns and their allies flourish well in moist and shady habitats.

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FESTI, DANIELA, WERNER KOFLER, and KLAUS OEGGL. "Comments on Brugger and others (2018) ‘A quantitative comparison of microfossil extraction methods from ice cores’." Journal of Glaciology 65, no. 250 (March 5, 2019): 344–46. http://dx.doi.org/10.1017/jog.2019.10.

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ABSTRACTIn our comments, we re-evaluate Brugger and others (2018) Lycopodium/Eucalyptus double marker approach, based on the fact that previous evidence already demonstrated that the batch of Eucalyptus tablets used by Brugger and others (2018) is not suitable for quantitative comparisons as they are characterized by inconsistent pollen concentration. We present clear evidence that the Eucalyptus tablets do feature inaccurate pollen concentrations, and are therefore improper for all quantitative comparisons of microfossil extraction methods. Consequently, the results of the quantitative and qualitative assessment of different pollen extraction methods from ice samples compiled by Brugger and others (2018) are highly questionable due to the use of faulty marker tablets.

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López-Sáez, José Antonio, Francisca Alba-Sánchez, Daniel Sánchez-Mata, Daniel Abel-Schaad, Rosario G. Gavilán, and Sebastián Pérez-Díaz. "A palynological approach to the study of Quercus pyrenaica forest communities in the Spanish Central System." Phytocoenologia 45, no. 1 (July 1, 2015): 107–24. http://dx.doi.org/10.1127/0340-269x/2014/0044-0572.

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A total of 75 surface samples collected from mosses in the Quercus pyrenaica forests of the Spanish Central System mountains were analysed for their pollen content. The samples were taken from six different Quercus pyrenaica phytosociological associations between 443 and 1657 m a.s.l. and fall within distinct rainfall and temperature regimes. The aims of this paper are to provide new data on the modern pollen rain from Central Spain, and to perform these data using multivariate statistics (hierarchical cluster analysis and principal component analysis) and pollen percentages. We could distinguish first between unaltered and disturbed forest landscapes and among different Quercus pyrenaica forest associations based on climatic gradients (rainfall pattern, summer moisture). This analysis allowed us to identify a set of pollen taxa markers which could assist in distinguishing these oak forest communities.

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Fall, Patricia L. "Pollen Taphonomy in a Canyon Stream." Quaternary Research 28, no. 3 (November 1987): 393–406. http://dx.doi.org/10.1016/0033-5894(87)90006-8.

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AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

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Sera, S. K. "Early Holocene pollen data from Mikir Hills, Assam, India." Journal of Palaeosciences 52, no. (1-3) (December 31, 2003): 121–26. http://dx.doi.org/10.54991/jop.2003.1760.

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The pollen analytical studies of a 1.5 m deep soil profile (12210±110 years BP at 80 cm level) from Kaki Forest Division in Mikir Hills of Assam have been carried out. The pollen investigation of surface samples was made to understand the pollen/vegetation relationship in the forest. However, the study of surface samples does not fully cohere with the present day set up of vegetation. Palynological studies of the sediment profile indicate that since the last 15,000 years there have been three stages of vegetational developments followed by a reducing environment at the beginning (150-120 cm) reflecting directly on brief phases of climate such as arid, semi-arid and warm and humid. The abundance of grasses both cultivated as well as wild throughout the pollen diagram has revealed the existence of an open savanna forest for a long period. The arboreal vegetation is represented by mixed tropical and subtropical trees and shrubs. Both monolete and trilete ferns are well documented in the assemblage. Occurrence of some degraded pollen and spores indicate the biodegradation of microbiota as evidenced by the presence of fungal spores and hyphae in almost all the sediments. The low occurrence of extra regional plant taxa like Pinus, Picea, Abies, Larix, Betula and Alnus in the sediments is indicative of long distance transportation of pollen from high elevation.

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Bell, Benjamin A., William J. Fletcher, Peter Ryan, Alistair WR Seddon, Roy A. Wogelius, and Rachid Ilmen. "UV-B-absorbing compounds in modern Cedrus atlantica pollen: The potential for a summer UV-B proxy for Northwest Africa." Holocene 28, no. 9 (June 11, 2018): 1382–94. http://dx.doi.org/10.1177/0959683618777072.

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Sporopollenin is a complex biopolymer which is the main component of the pollen grain exine and is partly composed of the aromatic compounds para-coumaric acid ( pCA) and ferulic acid (FA). These compounds absorb ultraviolet-B radiation (UV-B, 280–315 nm), and their abundance in pollen and spores has been shown to increase in response to increased UV-B flux. Here, we show that the relative abundance of UV-B-absorbing compounds (UACs) measured using Fourier Transform Infrared Spectrometry (FTIR) in modern pollen of autumn-pollinating Cedrus atlantica trees increases in response to summer UV-B flux. This relationship was observed in native Moroccan samples ( r2 = 0.84, p < 0.0001), but not across a larger environmental gradient including non-Moroccan samples ( r2 = 0.00, p = 0.99). For non-Moroccan samples of known provenance, the abundance of UACs is similar to the abundance of UACs found in samples from their place of origin. The FTIR spectra of these samples also closely resemble the FTIR spectra of samples from their place of origin. This unexpected finding suggests there could be a heritable component to UAC production possibly associated with epigenetic memory, an important adaptive mechanism in conifers. Our results indicate that the relative abundance of UACs in Cedrus atlantica pollen could be used as a proxy to reconstruct historic summer UV-B flux in Northwest Africa during at least the Holocene and Late Glacial period while also highlighting how UV-B proxies should be established using pollen samples from specimens growing in their native range or environment.

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Davis, Basil A. S., Manuel Chevalier, Philipp Sommer, Vachel A. Carter, Walter Finsinger, Achille Mauri, Leanne N. Phelps, et al. "The Eurasian Modern Pollen Database (EMPD), version 2." Earth System Science Data 12, no. 4 (October 9, 2020): 2423–45. http://dx.doi.org/10.5194/essd-12-2423-2020.

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Abstract. The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).

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Festi, Daniela, Luca Carturan, Werner Kofler, Giancarlo dalla Fontana, Fabrizio de Blasi, Federico Cazorzi, Edith Bucher, Volkmar Mair, Paolo Gabrielli, and Klaus Oeggl. "Linking pollen deposition and snow accumulation on the Alto dell'Ortles glacier (South Tyrol, Italy) for sub-seasonal dating of a firn temperate core." Cryosphere 11, no. 2 (April 13, 2017): 937–48. http://dx.doi.org/10.5194/tc-11-937-2017.

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Abstract. Dating of ice cores from temperate non-polar glaciers is challenging and often problematic. However, a proper timescale is essential for a correct interpretation of the proxies measured in the cores. Here, we introduce a new method developed to obtain a sub-seasonal timescale relying on statistically measured similarities between pollen spectra obtained from core samples and daily airborne pollen monitoring samples collected in the same area. This approach was developed on a 10 m core retrieved from the temperate-firn portion of Alto dell'Ortles glacier (Eastern Italian Alps), for which a 5-year annual/seasonal timescale already exists. The aim was to considerably improve this timescale, reaching the highest possible temporal resolution and testing the efficiency and limits of pollen as a chronological tool. A test of the new timescale was performed by comparing our results to the output (date of layer formation) of the mass balance model EISModel, during the period encompassed by the timescale. The correspondence of the results supports the new sub-seasonal timescale based on pollen analysis. This comparison also allows us to draw important conclusions on the post-depositional effects of meltwater percolation on the pollen content of the firn core as well as on the climatic interpretation of the pollen signal.

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Toledo, Mauro B. de, Ortrud M. Barth, Cleverson G. Silva, and Marcia A. Barros. "Testing multivariate analysis in paleoenvironmental reconstructions using pollen records from Lagoa Salgada, NE Rio de Janeiro State, Brazil." Anais da Academia Brasileira de Ciências 81, no. 4 (December 2009): 757–68. http://dx.doi.org/10.1590/s0001-37652009000400013.

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Despite the indisputable significance of identification of modern analogs for Paleoecology research, relatively few studies attempted to integrate modern and fossil samples on paleoenvironmental reconstructions. In Palynology, this general pattern is not different from other fields of Paleoecology. This study demonstrates the practical application of modern pollen deposition data on paleoenvironmental reconstructions based on fossil pollen by using multivariate analysis. The main goal of this study was to use Detrended Correspondence Analysis (DCA) to compare pollen samples from two sediment cores collected at Lagoa Salgada, a coastal lagoon located at northeastern Rio de Janeiro State. Furthermore, modern surface samples were also statistically compared with samples from both cores, providing new paleoecological insights. DCA demonstrated that samples from both cores are more similar than previously expected, and that a strong pattern, related to a paleoenvironmental event, is present within the fossil data, clearly identifying in the scatter plot samples that represent pre- and post-environmental change. Additionally, it became apparent that modern vegetation and environmental conditions were established in this region 2500 years before present (BP). Multivariate Analysis allowed a more reliable integration of modern and fossil pollen data, proving to be a powerful tool in Paleoecology studies that should be employed more often on paleoclimate and paleoenvironmental reconstructions.

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Lubliner-Mianowska, K. "Pollen analysis of the surface samples of bottom sediments in the bay of Gdańsk." Acta Societatis Botanicorum Poloniae 31, no. 2 (2015): 305–12. http://dx.doi.org/10.5586/asbp.1962.023.

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Bera, S. K. "Modern pollen deposition in Mikir hills, Assam." Journal of Palaeosciences 49, no. (1-3) (December 31, 2000): 325–28. http://dx.doi.org/10.54991/jop.2000.152.

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In the present investigation eight surface samples collected in a transact from within the forest to open land around Diphu-Lumding areas or Karbi Anglong District (Lat. 25°2' & 26° 1' N: Long. 92°44' & 93°42' E) in Assam were studied with a view to construct pollen spectra from Mikir hills of Assam.

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Bisui, Sourabh, Ujjwal Layek, and Prakash Karmakar. "Determination of Nectar Resources through Body Surface Pollen Analysis: A Study with the Stingless Bee Tetragonula iridipennis Smith (Apidae: Meliponini) in West Bengal, India." Sociobiology 68, no. 3 (August 14, 2021): e6173. http://dx.doi.org/10.13102/sociobiology.v68i3.6173.

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Knowledge about floral resources is essential for bee management and conservation. Pollen analysis of honey is the most traditional method for determining the nectar resources of a bee species. However, the collection of honey samples is difficult in cavity-nesting natural stingless bee colonies. Furthermore, it is detrimental to the wild bee’s colony and may threaten their survivability. We analyzed adhered body surface pollen of incoming nectar foragers (which were smeared incidentally during nectar foraging) as an alternative method to determine nectariferous flora of Tetragonula iridipennis in West Bengal, India. By this method, we have identified 75 pollen types. The number of obtained pollen types was lower in the human-altered habitats of Midnapore city (44 pollen types) than the semi-natural habitats of Garhbeta (71 pollen types). Excluding a few pollen types of non-nectariferous plants, most of the pollen types came from nectariferous plants of both crop and non-crop species. Non-crop flowering plants (viz. Ailanthus excelsa, Borassus flabellifer, Eucalyptus tereticornis, Lannea coromandelica, Peltophorum pterocarpum, and Tectona grandis) provided a significant amount of nectar to the bee species and, therefore, play an important role in the conservation of the bee species.

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Cao, Xianyong, Fang Tian, Kai Li, Jian Ni, Xiaoshan Yu, Lina Liu, and Nannan Wang. "Lake surface sediment pollen dataset for the alpine meadow vegetation type from the eastern Tibetan Plateau and its potential in past climate reconstructions." Earth System Science Data 13, no. 7 (July 21, 2021): 3525–37. http://dx.doi.org/10.5194/essd-13-3525-2021.

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Abstract. A modern pollen dataset with an even distribution of sites is essential for pollen-based past vegetation and climate estimations. As there were geographical gaps in previous datasets covering the central and eastern Tibetan Plateau, lake surface sediment samples (n=117) were collected from the alpine meadow region on the Tibetan Plateau between elevations of 3720 and 5170 m a.s.l. Pollen identification and counting were based on standard approaches, and modern climate data were interpolated from a robust modern meteorological dataset. A series of numerical analyses revealed that precipitation is the main climatic determinant of pollen spatial distribution: Cyperaceae, Ranunculaceae, Rosaceae, and Salix indicate wet climatic conditions, while Poaceae, Artemisia, and Chenopodiaceae represent drought. Model performance of both weighted-averaging partial least squares (WA-PLS) and the random forest (RF) algorithm suggest that this modern pollen dataset has good predictive power in estimating the past precipitation from pollen spectra from the eastern Tibetan Plateau. In addition, a comprehensive modern pollen dataset can be established by combining our modern pollen dataset with previous datasets, which will be essential for the reconstruction of vegetation and climatic signals for fossil pollen spectra on the Tibetan Plateau. Pollen datasets including both pollen counts and percentages for each sample, together with their site location and climatic data, are available at the National Tibetan Plateau Data Center (TPDC; Cao et al., 2021; https://doi.org/10.11888/Paleoenv.tpdc.271191).

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Theuerkauf, Martin, Anna Kuparinen, and Hans Joosten. "Pollen productivity estimates strongly depend on assumed pollen dispersal." Holocene 23, no. 1 (July 16, 2012): 14–24. http://dx.doi.org/10.1177/0959683612450194.

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Past plant abundance may be reconstructed from pollen data if dispersal distances of pollen and pollen productivities of each taxon are known. Using surface sediment samples from small and medium sized, closed and near circular lakes from lowland Central Europe, we tested the validity of three pollen dispersal models by comparing empirical pollen data from each lake with simulated pollen data derived from applying various pollen dispersal models to vegetation data from rings situated up to 100 km from each site. Pollen assemblages simulated with a Lagrangian stochastic (LS) model best fit real pollen assemblages, simulations with the commonly used Prentice model on pollen dispersal underestimated the amount of pollen arriving from distances larger than 10 km and overestimated the differences in dispersal distances between lighter ( Pinus) and heavier ( Fagus, Picea) pollen grains. The LS model appeared to provide more appropriate simulations. Pollen productivity estimates (PPEs) calculated for the data set showed that the choice of the dispersal model has great impact on the results. If derived with the Prentice model, PPEs for Fagus and Picea are three times higher than with the LS model. Studies on pollen productivities thus need to consider the apparent limitations of the Prentice model. We suggest an alternative approach, which uses simulations instead of the extended R-value model, to calculate PPEs. The approach is flexible in the use of dispersal functions and produced consistent results for two independent data sets from small and medium sized lakes.

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Pisaric, Michael FJ, Julian M. Szeicz, Tammy Karst, and John P. Smol. "Comparison of pollen and conifer stomates as indicators of alpine treeline in northwestern Canadian lake sediments." Canadian Journal of Botany 78, no. 9 (September 1, 2000): 1180–86. http://dx.doi.org/10.1139/b00-092.

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We compare fossil pollen and stomate assemblages in 29 lake sediment surface samples from mountainous regions in northwestern Canada to characterize the relationship between modern vegetation, and pollen and stomate deposition. Modern pollen spectra were dominated by arboreal taxa originating from lower elevation sites. Pinus pollen frequently reached 30% of the pollen sum, regardless of elevation. Alpine-tundra vegetation has lower pollen abundance, even in the alpine-tundra zone, where it dominates the sparse vegetation cover. Fossil stomates were observed in all but one site where trees currently exist in the vicinity of the lake, while no stomates were found in the sediments from alpine-tundra sites. The highest concentration of stomates occurred in lake sediments from closed-canopy forested areas. Our data suggest that different boreal forest types may be differentiated based on pollen assemblages and that the presence of stomates clearly distinguishes vegetation zones dominated by arboreal vegetation from alpine-tundra zones where trees are not present.Key words: pollen, conifer stomates, treeline, Pacific Northwest.

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Sánchez Juárez, D. L., G. Martínez Montes, and E. Rubio Rosas. "Chemical Characterization of Yellow and Orange Pollen (Helianthus annuus) and its Effect in the Growth of Hydroxyapatite." Materials Science Forum 755 (April 2013): 163–69. http://dx.doi.org/10.4028/www.scientific.net/msf.755.163.

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In this work orange pollen grains (Helianthus annuus) were immersed in a supersaturated ionic solution (similar to human extracellular fluid) during different times at 37 °C, atmospheric pressure and pH of 7.4. By Fourier transform infrared spectroscopy (FT-IR) we confirmed the presence of the functional groups carbonyl, amide I, amide II, carboxyl and phosphate in both samples. Nevertheless, yellow pollen owns a greater amount of phosphate groups than orange pollen. By scanning electron microscopy (SEM), differences in the morphology, shape and size of both samples were not observed. In orange pollen grains, amorphous agglomerates can be observed for periods smaller to 14 days and spherical structures formed by nanocrystals of laminar form were observed on their surface at 17 days. By energy dispersive spectroscopy (EDS) confirms the presence of calcium and phosphorous in the agglomerates with different Ca/P ratio and by X-ray diffraction (XRD) the hydroxyapatite (HAp) phase was verified.

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Bastl, Katharina, Maximilian Bastl, Uwe Berger, and Martina Weber. "Air and surface soil samples – two different pairs of shoes? Comparing the pollen spectrum on different days of the pollen season." Grana 58, no. 5 (July 1, 2019): 371–82. http://dx.doi.org/10.1080/00173134.2019.1615985.

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Tonkov, Spassimir, Sheila Hicks, Elissaveta Bozilova, and Juliana Atanassova. "Pollen monitoring in the central Rila Mountains, Southwestern Bulgaria: comparisons between pollen traps and surface samples for the period 1993–1999." Review of Palaeobotany and Palynology 117, no. 1-3 (October 2001): 167–82. http://dx.doi.org/10.1016/s0034-6667(01)00085-9.

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Journal articles on the topic 'Pollen surface samples'

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