Abundant Pollen Types Research Articles

The Study Of Airborne Pollen And Spores Circulating At “Head Level” In Nsukka Environment

The quantitative air spora investigation at “head” level in the dry season (November-February) revealed a substantial presence of pollen grains, fungal spores and such other component as fern spores, diatom frustules and plant debris. The trapped pollen grains are representative of trees, shrubs, weeds/herbs and grasses of both indigenous and introduced species. Trees and grasses (Poaceae) contributed 49.07% and 30.91% of total pollen, respectively. The qualitative pollen record indicates that more species of entomophilous plants were dominant in the pollen count, whereas pollen grains of anemophilous plants were found to predominate quantitatively. The most frequent and abundant pollen types include those of Poaceae (grasses), Elaeis guineensis, Casuarina equisetifolia, Alchornea cordifolia, Milicia excelsa, and Amaranthaceae / Chenopodiaceae. Fungal spores were found to dominate the entire component of the airborne spora counted. The most common fungal spores encountered include those of Cladosporium, Ustilago, Nigrospora, Drechslera /Helminthosporium and Pithomyces. Bio-Research Vol.2(2) 2004: 7-14

An illustrated key for the identification of pollen from Pantepui and the gran sabana (Eastern Venezuelan Guayana)

This work consists of a key, descriptions and illustrations, to identify the most significant angiosperm pollen types (85 genera/ species, belonging to 36 families), from a paleoecological point of view, of the Gran Sabana and the ‘tepui’ (table mountains) summits from eastern Venezuelan Guayana. The pollen key and plates contain the most frequent and abundant pollen types found so far by the author in the Holocene sediments, as well as the significant medium and minor elements. This is enough to carry out a standard, successful palynological analysis in the area with a small percentage of unknown taxa, and can be considered a first step to be enhanced with future studies, especially from the ‘tepui ‘ summits of the western Venezuelan Guayana.

Palynological differences in the pollen content of Eucalyptus honey from Australia, Portugal and Spain

A melissopalynological study was carried out on 75 samples of Eucalyptus honey from different countries (22 from Australia, 13 from Portugal and 40 from Northwest Spain), in which a total of 145 different pollen types were identified. Of such, only Eucalyptus, Acacia, Brassica, Echium, Ligustrum, Plantago, Rumex, Taraxacum, Trifolium and Vicia pollen are present in the honeys from all three countries. Among the most abundant pollen types in Australian honeys, those belonging to the following families stand out: Myrtaceae (Angophora and Melaleuca), Fabaceae, Asteraceae, Proteaceae and Euphorbiaceae, along with Raphanus, Echium and Citrus. In the Portuguese honeys, the presence of Fabaceae, Rosaceae and Cistaceae stands out, with Castanea and Erica as secondary pollen types, while Fabaceae, Asteraceae, Boraginaceae, Cistaceae and Scrophulariaceae are the families with the highest quantity of pollen types in the samples from Spain. In the latter, the most important secondary pollen types are: Castanea, Cytisus, Erica, Lotus, Salix and Rubus.

AN ILLUSTRATED KEY FOR THE IDENTIFICATION OF POLLEN FROM PANTEPUI AND THE GRAN SABANA (EASTERN VENEZUELAN GUAYANA)

This work consists of a key, descriptions and illustrations, to identify the most significant angiosperm pollen types (85 genera/species, belonging to 36 families), from a paleoecological point of view, of the Gran Sabana and the ‘tepui’ (table mountains) summits from eastern Venezuelan Guayana. The pollen key and plates contain the most frequent and abundant pollen types found so far by the author in the Holocene sediments, as well as the significant medium and minor elements. This is enough to carry out a standard, successful palynological analysis in the area with a small percentage of unknown taxa, and can be considered a first step to be enhanced with future studies, especially from the ‘tepui’ summits of the western Venezuelan Guayana.

Pollen and spores in the air of a hospital out-patient ward

Aerobiological studies of interest to the allergy specialist are routinely carried out using information from outdoor traps. However, most of our time is spent indoors and it is often the content of this air that is responsible for allergic phenomena. The air of a hospital outpatient ward was analyzed using two portable volumetric aerobiological traps, one at floor level and the other at a height of 1 meter. Both spores and pollen grains were counted and their values were compared with those outside the building. Twenty types of pollen grains were found. Their concentrations ranged from 2.7 and 25.1 grains/m3, with the most frequent being (in order) grasses, evergreen oak (holm and cork oaks), water plantain, and olive. Twenty two different types of spores were found with concentrations of between 175.0 and 1395.8 spores/m3 and the most frequent were Cladosporium, Ustilago and basidiospores. No significant differences were found between the floor level and the meter-high measurements. Comparison with outdoor levels showed that the three most abundant pollen types were correlated, with a ratio of 30:1 between indoor and outdoor levels. For the spores and fungi propagules, the indoor:outdoor ratio was highly variable, depending on the type. Thus, for Aspergillus-Penicillium spores, the concentration was even higher indoors than outdoors, although for most types, lower levels were found indoors, with a mean outdoor:indoor ratio of 4:1. We argue that this relationship reflects the presence of indoor spore sources. Rainfall was correlated with a decline in pollen levels and a rise in spore levels.

Influence of precipitation and temperature on airborne pollen concentration in Santiago de Compostela (Spain)

This paper presents data of airborne pollen concentration of Pinus , Platanus , Quercus , Betula , Poaceae and Castanea , the most abundant pollen types, during the last eight years, in Santiago de Compostela (NW Iberian Peninsula). We determined their respective principal pollen release periods and analysed statistically the influence of the main meteorological parameters on their pollen concentration, obtaining a negative correlation with precipitation and a positive correlation with temperature, in the majority of the cases, during these years. A detailed study of accumulated pollen values, in relation to accumulated average temperatures and the precipitation distribution, enabled us to establish a relationship between these parameters and the principal pollination period of each of these taxa.

Palynological characterization of honeys from Galicia (Northwest Spain)

The pollen content of a total of 530 honeys from the major beekeeping areas of Galicia (Northwest Spain) was analysed using the methods of Louveaux et al. (1978). The results indicate that Galician honeys can be divided into 5 groups in which the relative proportions of the five most abundant pollen types (Castanea saliva, Eucalyptus globulus, Rubus spp., Cytisus‐type and Erica spp.) vary between the different production areas. Honeydew is typically absent or present in negligible amounts and the total pollen content is typically low (despite the fact that the most important pollen types, Castanea and Eucalyptus tend to be over‐represented). Other pollen species such as (Diplotaxis erucoides, Hypecoum procumbens, Olea europaea, Cistus ladanifer, Helianthus animus, Citrus spp. and Lavandula spp.) which are abundant in honeys from the Mediterranean areas of Spain are absent or present only in very small amounts.

Airborne pollen in Kiev (Ukraine): Gravimetric sampling

This article presents the results of aeropalynological observations in Kiev, carried out with a gravimetric method, during January–October, 1994. The six most abundant pollen types were: Betulaceae (21%), Chenopodiaceae/Amaranthaceae (10%), Ambrosia (10%), Artemisia (9%) Pinaceae (8%) and Poaceae (6%). Seasonal fluctuations of the atmospheric presence of tree/shurb and herb/grass pollen during the period March–September, 1993 and 1994, are also shown.

A palynological study of surface and suspended sediments on a tidal flat: implications for pollen transport and deposition in coastal waters

This study examines patterns of pollen deposition and resuspension on a tidal flat of the Dollard, a tidal basin near the mouth of the Ems River, at the border of Germany and The Netherlands (Fig. 1). Sediment samples were collected during three sequential low tides at the spring stage of the lunar tidal cycle when the greatest area of the flat would be exposed and, with the exception of storm events, when maximum scour and redeposition would be expected to occur. Fifteen sample stations were selected along a 5 km transect, with paired ripple crest and trough samples collected at three stations. Water samples were collected hourly during two tidal cycles, from a single location on the flat. Both numbers and condition of pollen and spore taxa were determined for all samples. Grain size and LOI of suspended matter were also determined. The same eight types of pollen and spores were important in both water and sediment samples: Ericaceae, Alnus, Betula, Chenopodiaceae, Corylus, Gramineae and Polypodiaceae. In water samples the lack of a relationship between concentrations of some pollen types and mineral fractions is assumed to be evidence that certain pollen types are preferentially incorporated into floccules suspended in local waters. Analysis of tidal flat sediments indicates that pollen concentrations increase in troughs between ripples and at lower elevations where finer grain sizes accumulate. There is minimal evidence of selective sorting of pollen types. Ordination (using Principal Components Analysis) of pollen percentages and concentrations in sediments indicates that both elevation and distance from the estuary mouth influence concentrations of all abundant pollen types. These parameters, however, have minimal influence on pollen percentages. Incorporation of pollen into fecal pellets, which have relatively high settling velocities, is assumed to be a critical control on pollen deposition in this environment. Analysis of stomach contents of locally common bivalves supports this hypothesis. Transport and deposition of individual pollen types cannot be predicted as floccules and pellets have varying densities and settling velocities. Some pollen and spores may be deposited in coarser sediments than would be predicted based on the size and density of individual grains, but in general display predicted patterns of deposition of fine-grained clastic sediments.

Airborne pollen survey of the warsaw area

Abstract Airborne and allergenic pollen types were identified in the area of Warsaw in the years 1983–1987. Over the same period of time, skin tests reactions were analysed in 400 hay fever patients. The aim of our study was to determine whether the most abundant pollen types at a given time did evoke hay fever symptoms in our allergy patients as confirmed by positive skin responses. In February, March and April 10.8% of patients showed allergy to deciduous tree pollen, while in May allergy to conifer pollen was confirmed in 2%. The most numerous group of patients demonstrating pollinosis due to grass and rye pollen attended the Clinic in June and July. In the autumn (September-October) symptoms due to weed pollens predominated in our patients.

Fluctuations and trends in airborne concentrations of some abundant pollen types, monitored at Vienna, Leiden, and Brussels

Abstract The annual sums of daily airborne pollen concentrations fluctuate from year to year. It has been suggested that for some taxa there is a regular or alternating pattern in these fluctuations. On the other hand, environmental changes may lead to decreasing or increasing trends in airborne pollen concentrations. These two phenomena can only be studied reliably on the basis of long-term volumetric observations of abundantly occurring pollen types. For this study two arboreal (Betula and Quercus) and two herbaceous (Poaceae and Urtica) types were chosen. For some of these pollen types a weak but significant trend is observed. For the arboreal types (Quercus and Betula) there appears to be a rather constant biennial fluctuating rhythm.

Pollen frequencies reflect vegetation patterns in a great basin (U.S.A.) mountain range

Five indices are used to quantify the relationship between vegetation and pollen in a mountain range in the arid Great Basin. Computations are based on vegetation coverage and pollen percentages from 63 stands. Association is a measure of whether the presence of the pollen type in a surface sample is an indication of the presence of the parent plant in the local vegetation. Over-representation and under-representation measure tendencies for pollen to occur where the parent plants are absent and vice versa. The correlation coefficient measures the relationship between plant and pollen in stands where both are present. Twenty-nine trees, shrubs, and herbs accurately reflect local vegetation conditions. A percentage diagram shows elevational trends in abundant pollen types. Regional pollen types are used to compute the accumulation rate of pollen in the surface samples. A diagram of pollen accumulation rates shows trends similar to those shown in the percentage diagram. The moss polsters used in this study may collect pollen over a fifteen-year interval.

The contemporary distribution of pollen in eastern North America: A comparison with the vegetation

By mapping and summarizing 478 pollen counts from surface samples at 406 locations in eastern North America, this study documents the relationships between the distributions of pollen and vegetation on a continental scale. The most common pollen types in this region are pine, birch, oak, and spruce. Maps showing isopercentage contours or isopolls for 13 important pollen types reflect the general N-S zonation of the vegetation. The maps and tabulations of average pollen spectra for the six major vegetational regions indicate high values for the following pollen types in each region: (1) tundra-nonarboreal birch, sedge, and alder; (2) forest/tundra-spruce, nonarboreal birch and alder; (3) boreal forest-spruce, jack pine (type), and arboreal birch with fir in the southeastern part; (4) conifer/hardwood forest-white pine, arboreal birch, and hemlock with beech, maple, and oak in the southern part; (5) deciduous forest-oak, pine, hickory, and elm, with beech and maple in the northern part, and highest values of oak and hickory west of the Appalachian crest; and (6) southeastern forest-pine, oak, hickory, tupelo, and Myricaceae. In some cases, less abundant pollen types are diagnostic for the region, e.g., bald cypress in the southeast. In the conifer-hardwood region and southward, pollen of weeds associated with deforestation and agriculture is abundant. The maps also show that much of southeastern U.S. and the area just to the east of Hudson Bay are in need of additional sampling. At 51 of the sites, absolute pollen frequencies (APF; grains/ml lake sediment) were obtained. These confirm the major conclusions from the percentage data, but differences are evident, e.g., the percentages of alder pollen peak in the tundra whereas alder APFs peak in the boreal forest, and spruce percentages peak in the forest-tundra whereas spruce APFs peak in the boreal forest. Because the APF data reflect the patterns of absolute abundance of individual taxa in the vegetation as well as the overall forest densities, future counts of modern pollen should include APF determinations. The effects of sedimentation processes on APF quantities indicate that APF samples should be obtained from moderate size lakes of similar morphology and hydrology and that, in each lake, several samples from the profundal zone should be pooled to create a sample representative of that lake.