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Plant species of the family Urticaceae have periods of extensive and overlapping flowering. Two genera Urtica ( U. urens L., U. membranacea Poir. in Lam) and Parietaria ( P. judaica L .) are abundant throughout the Iberian Peninsula. Both have substantial allergenic potential, but patient sensitivity is specific to each genus. As a result, interest from the medical profession in the identification of the pollen from these genera has arisen. It would be useful to be able to estimate the relative percentages of pollen of these genera in the air, which would allow clinicians to recommend the appropriate safety measures to patients. Unfortunately, palynologists are unable to distinguish between the species of genera ( Parietaria and Urtica ). Additionally, traditional methods of pollen counting are laborious and therefore not optimal for routine on-line analysis. Recent biometrical analysis enables us to discriminate between pollen species of the genera Parietaria and Urtica , but they fail to solve the problem of genera identification. Alternative methods for counting and distinguishing genera of Urticaceae have long been awaited by medical experts among others. In this paper we present a computational system to discriminate between genera by using image analysis. It is based on the definition and computation of digital shape measures on pollen images taken by an optical microscope. The system correctly classifies more than 86% of all experiments done. A set of shape parameters are tested and the subset with the highest discrimination power includes: area (A), diameter (DM), mean distance to centroide (D mean ) and roundness (R) of the pollen grain. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyse whether the functional diversity of the fungal community follows the environmental gradients as much as vascular plants. After determination of the Ellenberg's indicator values on the basis of 602 cormophyte species occurring in 110 permanent plots across Central Europe, the relation between soil fungi and the abiotic factors as defined by Ellenberg's indicators has been evaluated. The palynological assessment proves that not the fungal occurrence, but the concentration of fungal remains is the most appropriate tool to unravel causal links between the belowground microflora and the soil abiotic factors. The analyses show a striking dichotomy within the fungal community. First, the logarithms of fungal diversity and hyphal density show close but opposite relationships with light, moisture, soil reaction and nitrogen availability. Second, fungal functional groups show parallel, decreasing trends for soil reaction and nitrogen availability. Aside from the mycorrhizal network as a whole (ericoid, EM and AM), we demonstrate that the degree of ecological information supplied by the different trophic levels (litter-related fungi, fimicolous fungi, wood-related fungi and strictly ericoid mycorrhizal fungi) is much greater than expected from previous studies. [ABSTRACT FROM AUTHOR]

At the beginning of 2020 the Austrian palynologist, Reinhard Zetter, turned 65. There are no limits when potential pollen samples are available, even nude diving as a last resort for the optimal aquatic pollen samples (Nitmiluk Gorge, Northern Territory, Australia, in 1988). Reinhard is very generous when sharing his knowledge and is always willing to assist students, friends, and colleagues when confronted with pollen-related dilemmas. Eocene Loranthaceae pollen pushes back divergence ages for major splits in the family. [Extracted from the article]

A detailed LM and SEM examination of the Upper Cretaceous Timerdyakh Formation microflora from the Vilui Basin yielded 13 Aquilapollenites, two Manicorpus, and three Azonia species. Comparisons with existing taxa from the Russian Federation and North America are impeded by the fact that many previously described forms were investigated using LM only, while SEM was very rarely used. Consequently, some of the pollen types reported in this study could not be ascribed to any previously documented taxa and have been described as nine new species. Further one previously described variety has been renamed. Except for two Azonia species and four Aquilapollenites species that also occur in Alaska, Canada and the Rocky Mountains in USA, the remaining taxa described here are restricted to the Late Cretaceous Khatanga-Lena-Subprovince. The several species unique to the Vilui Basin might indicate separate evolutionary paths for the genera Aquilapollenites and Manicorpus in North America and both northern and southern Asia during the Upper Maastrichtian. [ABSTRACT FROM AUTHOR]

In the south of the Caldén district (Phytogeographical province of Espinal, Argentina) the availability of flowering along with the botanical origin and protein content of pollen harvested by honey bees, was studied. During two apiculture periods (from end August to early January) pollen loads were collected every fortnight using pollen traps. A total of 637.96 g of pollen loads was analysed. From 139 species recorded, only 29 were visited by honey bees. In terms of biomass the contribution of exotic plants was high at the end of the winter (Brassicaceae and Erodium cicutarium ); during this period of pollen shortage, honey bees collected spores of Puccinia interveniens . During the spring, the native plants ( Condalia microphylla , Chuquiraga erinacea , Discaria americana , Grindelia tehuelches , Larrea divaricata , Prosopis sp., Prosopidastrum globosum and Vicia pampicola ) were utilised. Those pollen types of high protein level were collected most intensively. [ABSTRACT FROM AUTHOR]

The last fifty years have witnessed enormous developments in Quaternary pollen analysis in the Fennoscandian countries. This essay focuses on methodological and conceptual developments in Quaternary pollen analysis rather than on advances in vegetational history. Major methodological developments include improved field and laboratory methods, greater concern about project design and site selection, pollen representation studies and simulation modelling, and numerical methods and data synthesis. Conceptual advances include the glacial-interglacial cycle, the nature of the late-glacial flora and vegetation, ecological processes influencing the early Holocene forest development, the importance of human impact, pollen analysis of mineral soils, and the interpretation of pollen-stratigraphical data. Possible future developments are outlined and the uncertain future of Quaternary pollen analysis in Fennoscandia is considered. [ABSTRACT FROM AUTHOR]

Palynologic assemblages from late Quaternary sediments from Disko Bugt, central West Greenland, contain a new acritarch species described herein as Palaeostomocystis subtilitheca sp. nov. The type of the genus Beringiella , Beringiella fritilla Bujak 1984 , is transferred to the genus Palaeostomocystis Deflandre 1937 , and the new combination Palaeostomocystis fritilla ( Bujak 1984 ) is proposed. Palaeostomocystis subtilitheca sp. nov. and P. fritilla ( Bujak 1984 ) comb. nov. are characteristic of polar to subpolar environments and may be potential environmental indicators. [ABSTRACT FROM AUTHOR]

Three hundred and twenty-nine Greek honey samples of different botanical and geographical origin were collected and examined by organoleptic evaluation, melissopalynological analysis, measurement of electrical conductivity and colour. The results showed that 208 samples were unifloral with 178 of them representing the main types of unifloral honey produced in Greece; that is fir, pine, chestnut, cotton, orange and thyme honey. All honeys had the sensory characteristics typical of their origin and complied with the electrical conductivity standards set by Council Directive 2001/110/EC. Fir and pine honeydew honey had a low honeydew element/pollen (HDE/P) ratio and belonged to Maurizio's Classes II or III. The pollen types identified in these honeys ranged from 11 to 45%. Chestnut nectar honey contained >90% chestnut pollen, had a total number of plant elements of >245,000/10 g, and low pollen diversity. Cotton honey contained 1.2 to 16.5% cotton pollen, belonged to Maurizio's Class II, and had 22 pollen types, with Castanea sativa L. present in all samples. Orange honey contained 2.9 to 26.5% Citrus spp. pollen, belonged to Maurizio's Class II, and was characterized by the presence of Brassicaceae, Fabaceae, Olea europea L., Quercus coccifera L. and Rosaceae. In thyme honeys Thymus capitatus Hoffm. & Link. pollen was secondary or predominant ranging from 18.3 to 69.3%. These honeys belonged to Maurizio's Classes I or II and contained greater than 30 pollen types. Other Lamiaceae, Hypericum spp., Brassicaceae, Fabaceae, Rosaceae, and Cistus spp. pollen types appeared in the greatest number of thyme samples. [ABSTRACT FROM AUTHOR]

Since the beginning of aeropalynology, aerobiologists have tried to develop models able to predict the pollen load of the atmosphere to help physicians and patients suffering pollen allergies to improve the efficiency of pollen allergies prophylaxis. Some models have been developed by aerobiological services and are used for real time predictions, now provided online. They are statistical models and require the pollen load of the previous days as input, as well as statistics on the pollen load of the previous years, daily meteorological data and geographic information on the pollen sources. Here we propose to use process-based phenological models to predict the time course of the pollen load of the atmosphere using solely daily mean temperatures as input. The model proposed has been fitted and validated for 13 major allergenic taxa ( Alnus , Artemisia , Betula , Castanea , Corylus , Cupressaceae, Olea , Plantago , Platanus , Populus , Poaceae, Quercus and Tilia ) in different areas of France and Spain. The model has been integrated into a freeware called PPF (Positive Pollen Forecast), which will be made available from the 5 th Framework EU project POSITIVE web page at: http://www.forst.tu-muenchen.de/LST/METEOR/positive/. [ABSTRACT FROM AUTHOR]

Temperature is one of the main factors affecting the start of flowering in tree species that flower at the beginning of spring. Knowledge of the chilling and heat needs required by plants to overcome the period of dormancy enables us to determine the onset of pollination, which is of great importance to allergy sufferers. This study attempted to obtain behaviour models with a view to determining both the onset of the olive pollen season and daily pollen concentrations during the pollination period in Vigo. Monitoring was carried out using a Lanzoni VPPS 2000 pollen trap, from 1995 to 2002 inclusive. Olea pollen is mainly detected during the spring, principally in May. Given the geographical location, the very limited presence of this tree in the study area and the low Olea pollen concentrations detected in northern Spain as a whole, the values recorded here in the atmosphere of Vigo are particularly striking. A strong correlation was observed between total quantity olive pollen collected over the season and rainfall recorded during the second fortnight in February. According to the proposed model, an average of 680 Chilling Hours (CH) are necessary to overcome the chill period and break the state of bud dormancy, and 481 Growth Degree Days (GDD) °C are needed to induce flowering. Models for predicting daily mean pollen concentrations combine temperature and the previous days' pollen concentrations as predictor variables to provide a high level of prediction. [ABSTRACT FROM AUTHOR]

Pollen grains of 24 species of Brunellia were examined with LM and SEM, in order to find additional taxonomic information for phylogenetic analysis. The pollen grains were found to be 3- colporate, tectate and to have variable exine pattern. Five types of exine pattern were observed: striate-reticulate (large lumina and high muri) to finely reticulate, modified reticulate (muri and lumina irregular in shape and at various levels), modified rugulate (irregular and with protruding tectal elements) and punctate (the lumina are smaller and rounded to slit-shaped). With reference to indication of taxonomic relationships the exine pattern is not informative at all; however it is useful, for defining taxonomic species as it is correlated to vegetative, inflorescence and fruit characteristics. It seems that the punctate type could be a plesiomorphic character while modified reticulate is a synapomorphy. Relationships in the pollen morphology of Brunellia and certain genera of Cunoniaceae are discussed. El polen de 24 especies de Brunellia fue examinado en el microscopio de luz (ML) y el microscopio electrónico (MES) para encontrar información taxonómica adicional y usar esta información en el estudio de relaciones filogenéticas. El grano de polen es 3-colporado, tectado y con una alta variabile ornamentación de la exina. Se observaron cuatro categorías en la ornamentación de la exina del grano de pollen: reticulado estriado (luminas grandes y muros altos) a finamente reticulado, reticulado modificado (muros y lúminas de forma irregular y en varios niveles), rugulada modificada (irregular y proyectando elementos tectales) y la ornamentación de tipo punteado (las lúminas son pequen~as redondeadas o en forma de líneas). Desde el punto de vista de relaciones filogenéticas la ornamentación de la exina es parcialmente un carácter informativo. Sin embargo, la ornamentación es útil para definir las especies taxonomicamente por la correlacion de este carácter con caracteres vegetativos, de inflorescencia o del fruto. El tipo de ornamentación punteado parece ser el estado plesiomórfico, mientras que la ornamentación modificada reticulada es una sinapomorfıa. Se discuten las relaciones del grano de polen de Brunellia y ciertos géneros de Cunoniaceae. [ABSTRACT FROM AUTHOR]