High Pollen Concentrations Research Articles

Holocene climate variations retrieved from Gun Nuur lake-sediment core in the northern Mongolian Plateau

Our pollen-based climate reconstruction shows that both temperature and moisture were low during the early Holocene from ~10,000 to ~8000 cal. a BP and gradually climbed from ~8000 to ~6000 cal. a BP. The last ~6000 years have been generally warm and wet with high-amplitude fluctuations. The high-moisture conditions for the past ~6000 years are not only corroborated by high arboreal pollen/non-arboreal (AP/NAP; trees and shrubs over herbs) pollen ratio and high pollen concentration but also by high organic matter content and diatom data. We suggest that lower winter insolation and remaining ice covers in the early Holocene might have slowed down temperature rise in the continental interiors and that the resulted low temperature might have suppressed regional evaporation that was a major water vapor source for precipitation. At the same time, icemelt-water injection into the North Atlantic Ocean might have also suppressed water vapor supplies to the downwind areas, including the northern Mongolian Plateau. The increase in winter insolation and the final melting of ice sheets, together with the increased atmospheric CO2 concentration and the associated increase in atmospheric water vapor, could be responsible for the higher temperature during the past ~6000 years. The icemelting and the associated rise of sea level during the past ~6000 years might be responsible for the weakening of the winter monsoon in the interior of Asian continent, thus alluring farther eastward penetration of the relatively warm and wet Atlantic air masses and consequently bringing more precipitation to the northern Mongolian Plateau.

Variability of phenological stages of Dactylis glomerata in dependence on meteorological conditions in the Czech Republic

pressure (SLP) and 500 hPa geopotential height pattern over Europe on days with high concentration of ragweed pollen in Poznan in years 1996-2010. Methods: Ambrosia pollen data was collected by Hirst-type volumetric spore trap. Pollen grains were counted under the optical microscope (magni cation: 400x) and expressed as P m-3. Daily pollen concentrations were clustered in three intervals: low ( 30 Pm3) levels. For days attributed to these groups, synoptic charts were created on the basis of see level pressure (SLP) records from NCEP/NCAR reanalysis [2]. In addition, maps of 500 hPa geopotential heights were constructed. e method of interpolation was kriging. Results: Overall, 206, 23 and 17 days with low, medium and high concentration of ragweed pollen (respectively) were recorded in Poznan in years 1996-2010. Synoptic charts showed (Fig. 1) that during days with high pollen count of Ambrosia in Poznan the high pressure center was located in the area of northern Belorussia. e lowest pressure center was located over Iceland and the Atlantic Ocean in the south of the Iceland. As the geostrophic wind is parallel to the isobars and approximately determines the air mass transfer, it can be concluded that presented pressure pattern causes the air motion exactly from the Pannonian Plain to Poland, with south-east direction. Conclusions: e mechanism of long-range transport of Ambrosia pollen from Balkans to Poland highlighted by Sikoparija et al. [1] seems to be valid in all days with high concentrations of Ambrosia pollen in Poznan, 1996-2010. Averaged synoptic charts con rm that the air mass transport occurs from southeast to northwest with the strong high pressure center over Belorussia. When that pressure pattern is observed in weather forecast during August or September there is a possibility to record Ambrosia pollen in Poznan.

An operational model for forecasting ragweed pollen release and dispersion in Europe

The paper considers the possibilities of modelling the release and dispersion of the pollen of common ragweed (Ambrosia artemisiifolia L.), a highly allergenic invasive weed, which is spreading through southern and central Europe. In order to provide timely warnings for the allergy sufferers, a model was developed for forecasting ragweed pollen concentrations in the air. The development was based on the system for integrated modelling of atmospheric composition (SILAM) and concentrated on spatio-temporal modelling of ragweed flowering season and pollen release, which constitutes the emission term.Evaluation of the new model against multi-annual ragweed pollen observations demonstrated that the model reproduces well the main ragweed pollen season in the areas with major plant presence, such as the Pannonian Plain, the Lyon area in France, the Milan region in Italy, Ukraine and southern Russia. The predicted start of the season is mostly within 3 days of the observed for the majority of stations in these areas. The temporal correlation between modelled and observed concentrations exceeds 0.6 for the bulk of the stations.Model application to the seasons of 2005–2011 indicated the regions with high ragweed pollen concentrations, in particular the areas where allergenic thresholds are exceeded. It is demonstrated that, due to long-range transport of pollen, high-concentration areas are substantially more extensive than the heavily infested territories.

Investigation of the diurnal pattern of the vertical distribution of pollen in the lower troposphere using LIDAR

Abstract. The diurnal pattern of the vertical distribution of biogenic pollen in the lower troposphere was investigated by LIDAR. Meteorological data were taken at the ground. Pollen concentrations were measured at the surface using a Burkard 7-day-recording volumetric spore sampler. Aerosol extinction coefficients and depolarization ratios at 532 nm were obtained from LIDAR measurements in spring (4 May–2 June) 2009 in Gwangju, South Korea. Linear volume depolarization ratios varied between 0.08 and 0.14 and were observed only during daytime (09:00–17:00 local time (LT)) during days of high pollen concentration (4 to 9 May). Daily average pollen concentrations ranged 1000–2500 cm−3 in the same period. The temporal evolution of the vertical distribution of the linear volume depolarization ratio showed a specific diurnal pattern. Linear volume depolarization ratios of more than 0.06, were measured near the surface in the morning. High depolarization ratios were detected up to 2 km aboveground between 12:00 and 14:00 LT, whereas high depolarization ratios were observed only close to the surface after 17:00 LT. Low values of depolarization ratios (≤0.05) were detected after 18:00 LT until the next morning. During the measurement period, the daily variations of the high depolarization ratios close to the surface showed correlation to number concentration measurements of pollen. This finding suggests that high depolarization ratios could be attributed to enhanced pollen concentrations. The diurnal characteristics of the high values of depolarization ratios are thought to be closely associated with turbulent transport. Diurnal and vertical characteristics of pollen, if measured continuously, could be used to improve the accuracy of pollen-forecasting models via data assimilation studies.

독도 인근 해저퇴적물과 유기 퇴적물 분포 특성

Sediment transport mechanism and distribution of organic sediments are elucidated by the study of particle size, mineralogy, organic matters and microfossils of the surface samples collected from seafloor adjacent Dokdo island. Shallow marine sediments are dominated by coarse- grained sediments including gravel and sand, and their sedimentation has mainly been controlled by traction. While the samples collected from oceanic zone are characterized by high contents of fine- grained sediments such as silt and mud in bulk sediments, and the changes of mineral compositions including clay minerals and feldspar, and the fine sediments have been deposited mainly by suspension. The change of organic sedimentary communities is detected between neritic and oceanic zone. Although marine organic matter is predominant in neritic zone, terrestrial organic matter is monopolized according to increasing water depth. This trend is associated with grain size of sediments. The results also suggest that high pollen concentrations in whole organic matters may played an important role in excessive organic carbon in sediment.

Tree Pollen Spectra and Pollen Allergy Risk in the Osijek-Baranja County

The forests of north-eastern Croatia, as well as various plants and trees in the parks and streets of the Osijek-Baranja County, produce large amounts of pollen during the pollen season, which can cause allergy symptoms in pollen sensitive individuals. The aim of this study was to determine the most frequent types of pollen in this area and estimate possible health risks, especially the risk of allergy. In 2009 and 2010, the staff of the Health Ecology Department of the Osijek Public Health Institute monitored tree pollen concentrations in four cities from the Osijek - Baranja County (Osijek, Našice, Đakovo and Beli Manastir) using a Burkard volumetric instrument. The results were affected by weather conditions. Windy and sunny days facilitated the transfer of pollen, whereas during rainy days, the concentration of pollen grains decreased. High pollen concentrations of Cupressaceae/Taxaceae, Betulaceae, Salicaceae and Aceraceae could be the cause for symptoms of pollen allergy. In 2009, conifers, birch and poplar pollen were dominant at all monitoring stations with 5000 pollen grains (PG), 3188 PG and 3113 PG respectively. The highest number of pollen grains was recorded at measuring site Osijek. The variations in airborne pollen concentration between pollen seasons were recorded at all monitoring stations. The most obvious variations were recorded at measuring site Osijek. The usual pollination period lasts two to three months, which means that most pollen grains remain present from February to early June. However, the Cupressaceae / Taxaceae pollination periods last the longest and their pollen grains remain present until the end of summer. The risk of allergy was determined at four monitored measuring stations and the obtained data confirmed that the largest number of days with a high health risk was at the Đakovo measuring station for a species of birch. The research information aims to help allergologists and individuals allergic to plant pollen develop preventive measures and proper treatment therapies.

Dynamics and behaviour of airborne Quercus pollen in central Iberian Peninsula

Quercus pollen is one of the most abundant pollen types in the atmosphere of central Iberian Peninsula (Spain), as a consequence of the extensive representation of well-preserved forests and shrub communities dominated by species of the genus Quercus in this area. This paper analysed key features of the Quercus pollination season in the central Iberian Peninsula and the influence of weather-related variables on airborne Quercus pollen concentration through statistical techniques of correlation analysis and the use of a decision tree model for predicting pollen concentrations. Quercus species are very common in Spain and Portugal, dominating a number of ecosystems including Mediterranean forests. This gives rise to very high airborne Quercus pollen concentrations, particularly in spring. Sampling was carried out over a 6-year period using a Hirst volumetric sampler, and the sampling procedure established by the Spanish Aerobiology Network. Results show that between 92 and 98.5 % of total annual airborne Quercus pollen was recorded in the April–June period. Annual pollen index were high in all study years, averaging 12,344 grains, but it should be highlighted that pollen production was highly variable between years. Correlations between mean daily Quercus pollen concentration and weather-related variables showed that in the pre-peak period, a significant positive correlation was observed with the mean daily temperature and the hours of sunshine and a negative correlation was observed with the humidity and the rainfall. In the post-peak period, a significant negative correlation was found with the mean daily temperature and the hours of sunshine. The predictions obtained in the decision tree model showed a moderate significant correlation (r = 0.42) with the daily Quercus pollen concentration predicted and the one observed. Temperature is the most influential variable in the release of Quercus pollen.

Influence of biogenic pollen on optical properties of atmospheric aerosols observed by lidar over Gwangju, South Korea

For the first time, optical properties of biogenic pollen, i.e., backscatter coefficients and depolarization ratios at 532 nm were retrieved by lidar observations. The extinction coefficient was derived with the assumption of possible values of the extinction-to-backscatter (lidar) ratio. We investigate the effect of the pollen on the optical properties of the observed atmospheric aerosols by comparing lidar and sun/sky radiometer measurements carried out at the lidar site. The observations were made with a depolarization lidar at the Gwangju Institute of Science & Technology (GIST) in Gwangju, Korea (35.13°N, 126.50°E) during an intensive observational period that lasted from 5 to 7 May 2009. The pollen concentration was measured with a Burkard trap sampler at the roof top of the Gwangju Bohoon hospital which is located 1 km away from the lidar site. During the observation period, high pollen concentrations of 1360, 2696, and 1952 m−3 day−1 were measured on 5, 6, and 7 May, respectively. A high lidar depolarization ratio caused by biogenic pollen was only detected during daytime within the planetary boundary layer which was at 1.5–2.0 km height above ground during the observational period. The contribution of biogenic pollen to the total backscatter coefficient was estimated from the particle depolarization ratio. Average hourly values of pollen optical depth were retrieved by integrating the pollen extinction coefficients. We find average values of 0.062 ± 0.037, 0.041 ± 0.028 and 0.067 ± 0.036 at 532 nm on 5, 6, and 7 May, respectively. The contribution of pollen optical depth to total aerosol optical depth was 2–34%. The sun/sky radiometer data show that biogenic pollen can affect optical properties of atmospheric aerosol by increasing aerosol optical depth and decreasing the Ångström exponent during daytime during the season of high pollen emission.

First annual register of allergenic pollen in Talca, Chile

BackgroundThere are no data on atmospheric pollen in Talca. In the present work, our aim is to describe the amount of pollen grain in the atmosphere of the city of Talca likely to cause pollinosis of its inhabitants. MethodsA volumetric Hirst sampler (Burkard seven-day recording device) was used to study pollen levels. It was placed in the centre of Talca from May 2007 to April 2008. ResultsThe highest airborne presence of pollen, as measured in weekly averages, was Platanus acerifolia with a maximum weekly daily average of 203grains/m3 registered during September and October. The second highest was Acer pseudoplatanus with a maximum weekly daily average of 116grains/m3. Populus spp. had a maximum weekly daily average 103grains/m3. Olea europaea reached 19grains/m3 in November. Grasses presented high levels of pollen counts with a maximum weekly daily average of 27grains/m3 from the end of August until the end of January. Pollens of Plantago spp. Rumex acetosella and Chenopodium spp. had a similar distribution and were present from October to April with maximum weekly daily average of 7grains/m3, 7grains/m3 and 3grains/m3 respectively. Significant concentrations of Ambrosia artemisiifolia were detected from February until April. ConclusionThe population of Talca was exposed to high concentrations of allergenic pollen, such as P. acerifolia, A. pseudoplatanus, and grasses in the months of August through November. The detection of O. europaea and A. artemisiifolia is important as these are emergent pollens in the city of Talca. Aerobiological monitoring will provide the community with reliable information about the level of allergenic pollens, improving treatment and quality of life of patients with respiratory allergy.

Recent scenario of airborne pollens of Lucknow, India with special reference to intra- and interannual, diurnal, and vertical variation

Recent scenario of airborne pollens of Lucknow, India with special reference to intra- and interannual, diurnal, and vertical variation Kalyani Datta, Avijeet Chatterjee, Deepti Nigam, Sudhir P Singh, Praveen C VermaNational Botanical Research Institute (CSIR), Rana Pratap Marg, Lucknow, Uttar Pradesh, IndiaAbstract: Biomonitoring of airborne pollen in Lucknow, India was conducted for 2 consecutive years (August 2005–July 2007) with the objective of assessing the recent status of airborne pollen of the city and analyzing the intra- and interannual variations. Determination of total incidence of airborne pollen with subsequent contributions of individual components was carried out by measuring diurnal and vertical gradients. The Pearson correlation test was conducted to analyze pollen counts for 2 successive years. Principal component analysis was also carried out to examine the relative distribution of major pollen samples according to their dominance in the particular environment for 2 consecutive years. A total of 6089 pollen grains were caught in 2005–2006, which included 77 types against 4335 pollen grains comprising 61 types registered in 2006–2007. Two major pollen seasons, ie, spring and autumn, were confirmed. During 2005–2006, the highest airborne pollen concentration was found in February (154.67/m3), while the spring pollen peak was shifted to March (133.7/m3) in the consecutive year. The second pollen peak in both years was in August, which included mostly grass pollen. The highest airborne pollen contributor of 2005–2006 was grass, accounting for 25% of total pollen, while in the subsequent year Holoptelea dominated with 47% of total pollen. The diurnal analysis showed that the highest pollen concentration in 2005–2006 was around 2 pm due to abundant flowering of Morus, while in 2006–2007, the maximum concentration was reported at 10 am due to Holoptelea pollen. Inter-annual species variation in climate was also considered as an important factor involved in inter-annual variation in pollen incidence. In general, a positive correlation was observed with temperature, particularly average temperature. During each period, peak pollen counts occurred when the average temperature fell within the range of 22°C–23°C.Keywords: airborne pollen, diurnal fluctuation, inter-annual variation, pollen incidence

Forest clearance and agricultural expansion on Rapa, Austral Archipelago, French Polynesia

Palynological records from Holocene wetland deposits in East Polynesia have demonstrated widespread ecological changes following Polynesian arrival after c. ad 1200, but linking inferences of human activities to archaeological records has been limited by equivocal fossil proxies and a lack of chronological controls. To address these limitations, multiple sedimentary profiles were examined from a coastal marsh on the remote East Polynesian island of Rapa. These profiles span 8000 years of ecological change and record mid-Holocene sea-level highstand conditions which receded to modern levels by ad 500. Depositional models were constructed for each profile using Bayesian inferences to characterise the spatial and temporal changes in fossil proxy representation. Just prior to human arrival there are high pollen concentrations of Pandanus and the presence of an extinct palm, both indicative of an extensive lowland swamp forest that developed after ad 500. Indicators of Polynesian arrival and agricultural expansion include unprecedented amounts of charcoal particles and pollen from the introduced cultigen, Colocasia esculenta (taro). The swamp forest was progressively cleared, beginning in the most inland section at ad 1110–1230. The Colocasia-based agricultural system reached its greatest extent from ad 1590 to 1740. The last appearance of the extinct palm was recorded at ad 1520–1660 and the entire area was cleared of indigenous trees soon after European colonisation at ad 1830–1880. By modelling the chronologies of individual fossil proxies across each profile, we have developed a framework for defining the processes behind vegetation change and for matching palynological-based inferences of human activity with archaeological records.

A 1000-year record of vegetation change and wildfire from maar lake Erlongwan in northeast China

A high-resolution (∼every 20 y) pollen and charcoal record from Erlongwan maar lake (EML) documents the vegetation history and fire activity of the Long Gang region (northeast China) over the past millennium. The age–depth model is based on 137Cs, 210Pb measurements, and one calibrated 14C-AMS date at the base of the core. For much of the record, vegetation was dominated by a mixed conifer-hardwood forest. Pollen and charcoal concentrations reveal considerable variability during the past 1000 years. Between 980 and 1500 AD both pollen and charcoal reached maximum concentrations (∼1100 AD and 1300 AD respectively). The high pollen concentration was indicative of prevailing moist conditions during the period commonly referred to as the Medieval Climatic Anomaly (MCA). The high concentration of charcoal indicated high frequency and intensity of wildfire during the MCA, probably linked to high biomass productivity and less snow in winter. Between 1500 and 1850 AD both pollen and charcoal concentrations were low, indicative of colder winters with higher snowfall, relative drier summers and less intensive wildfire, coincidence with the cold period commonly known as the Little Ice Age (LIA). During 1900–1950 AD year, the highest relative abundance of Artemisia and the lowest abundance of Pinus together with high concentration of charcoal indicated strong human activity. The pollen data are in broad agreement with a previous study from an adjacent lake, indicating regional rather than localized human impact.

Erratum to: Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

V. MadžarevicAndrija Mohorovicic Geophysical Institute,DepartmentofGeophysics,FacultyofScience,UniversityofZagreb,Horvatovac 95,10000 Zagreb, Croatiae-mail: telisman@gfz.hrL. SrnecMeteorological and Hydrological Service of Croatia, Zagreb,Croatia,Gric 3,10000 Zagreb, CroatiaR. PeternelUniversity of Applied sciences Velika Gorica,Velika Gorica, CroatiaI. Hrga

Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m(3)) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m(3). Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

라이다를 이용한 지역 대기중 꽃가루의 광학적 두께 산출

Air-borne pollen, biogenically created aerosol particle, influences Earth's radiative balance, visibility impairment, and human health. The importance of pollens has resulted in numerous experimental studies aimed at characterizing their dispersion and transport, as well as health effects. There is, however, limited scientific information concerning the optical properties of airborne pollen particles contributing to total ambient aerosols. In this study, for the first time, optical characteristics of pollen such as aerosol backscattering coefficient, aerosol extinction coefficient, and depolarization ratio at 532 nm and their effect to the atmospheric aerosol were studied by lidar remotes sensing technique. Dual-Lidar observations were carried out at the Gwangju Institute of Science & Technology (GIST) located in Gwagnju, Korea (35.15Š E, 126.53Š N) for a spring pollen event from 5 to 7 May 2009. The pollen concentration was measured at the rooftop of Gwangju Bohoon hospital where the building is located 1.0 km apart from lidar site by using Burkard trap sampler. During intensive observation period, high pollen concentration was detected as 1360, 2696, and 1952 m _ 3 in 5, 6, and 7 May, and increased lidar return signal below 1.5km altitude. Pollen optical depth retrieved from depolarization ratio was 0.036, 0.021, and 0.019 in 5, 6, and 7 May, respectively. Pollen particles mainly detected in daytime resulting increased aerosol optical depth and decrease of Angstrom exponent.

219 The Revised Edition of Korean Calendar for Allergenic Pollens

BackgroundThe old version of pollen calendar was used until this year in South Korea. That calendar did not reflect current pollen distribution and concentrations that can be influenced by changes in weather and environment. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in 8 regions nationwide between 1997 and 2009 in South Korea.MethodsThe distribution of pollen grains was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) nationwide for 12 years between July 1, 1997 and June 30, 2009. Pollen were collected by using Burkard 7-day sampler (Burkard manufacturing Co Ltd, Hertfordshire, UK), and the collected pollens were sent every week to Hanyang Guri Hospital. Then pollens were strained with Calberla's fuchsin staining solution and were identified. The number of pollen grains per m3 was calculated.ResultsAlder, birch and Japanese cedar started to appear in February. Japanese cedar showed a highest pollen concentration in Jeju. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. Common ragweed appeared in the middle of August and showed the highest pollen concentration in the middles of September. Japanese hop showed a high concentration between the middle of August and the end of September, and mugwort appeared in the middles of August and its concentration increased up until early September. Birch appeared earlier in Kangneung, and pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja, alder and juniper produced a large concentration of pollens. Pine produced a large concentration of pollens between the middle of April and the end of May. Weeds showed higher concentrations in September and mugwort appeared earlier than common ragweed. In Busan where is the southeast city, the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among all areas. In Kwangju, Oriental thuja and hazelnut appeared in early February. In Jeju which is the end of southern island, Japanese cedar showed a higher pollen concentration than the other areasConclusionsNew information on pollen distributions and concentrations should be provided for the general publics or allergic patients through the website in order to prevent the occurrence of pollinosis.

The effect of meteorological factors on airborne Betula pollen concentrations in Lublin (Poland)

The present study investigated the pattern of the birch atmospheric pollen seasons in Lublin in the period 2001–2010. Pollen monitoring was conducted using a Lanzoni VPPS 2000 sampler. The atmospheric pollen seasons were determined with the 98% method. Regression analysis was used to determine correlations between meteorological conditions and the pattern of the birch pollen season. On average, the birch pollen season started on 12 April, ended on 13 May, and lasted 32 days. The peak value and the Seasonal Pollen Index showed the greatest variation in particular years. All the seasons were right-skewed. During the study years, a trend was found towards earlier occurrence of the seasonal peak. Regression equations were developed for the following parameters of the atmospheric pollen season: start, duration, peak value and average pollen concentration during the season. The obtained model fit was at a level of 64–81%. Statistical analysis shows that minimum temperature of February and March and total rainfall in June in the year preceding pollen release have the greatest effect on the birch atmospheric pollen season in Lublin. Low temperatures in February promote the occurrence of high pollen concentrations.

Ragweed (Ambrosia) pollen in aeroplankton of Upper Silesia

The work contains the analysis of <i>Ambrosia</i> pollen producing seasons in the atmosphere of Upper Silesia in the years 1998 - 2004. The research was carried out applying a volumetric method (Burkard pollen sampler) in Sosnowiec and the gravimetric method, for comparative purposes, in Sosnowiec, Będzin, Czeladź and Katowice. The highest pollen concentration in the research years was found in Sosnowiec and in 1999 in Czeladź. The ambrosia pollen in aeroplankton was noticed in the first ten days of August until the middle of October. The maximum pollen concentrations were from 16 August to 21 September. The highest pollen concentration was found in 1999 and 2002 (222 and 127 grains per 1m<sup>3</sup> per 24h) on September 4<sup>th</sup>, the lowest concentration in 2001. Two genera - <i>Ambrosia artemisiifolia</i> and <i>A. psilostachya</i> - can be found over an area of Upper Silesia. They constitute the main source of pollen in aeroplankton, but its transportation from distant areas cannot be excluded. The pollen of these plants can be transported by the wind from neighbouring countries (the Czech Republic, Slovakia, Ukraine, Hungary).

Flowering and airborne pollen - a novel statistical approach

The time pattern of flowering significantly affects the pollen season, its beginning, length and the concentration of pollen grains in air. The forecasting models used in aerobiological studies were chiefly based on the elements of weather conditions; however, recently the phenology of pollen shedding has been taken into consideration in these models more and more frequently. The aim of the presented investigations was to determine to what extent the flowering and the occurrence of allergenic pollen grains in air coincided in time. The investigation was carried out in Rzeszów (SE Poland) in the years 2003-2004. The flowering of 19 allergenic plant species was observed and seven phenophases were distinguished. Aerobiological monitoring was based on the volumetric method. In the case of most herbaceous plants, the flowering period overlapped the pollen season, high concentrations of pollen being recorded throughout several phenophases. In general, the pollen of trees occurred during very short periods, frequently during one phenophase, while the investigated phenomena were missing each other. The most intensive growth of inflorescences of alder, hazel and birch was observed at the beginning of full fl owering or towards the end of full flowering.

Pollen calendar of Lublin, 1995-2000

The measurements of pollen fall were carried out in Lublin in 1995 - 2000 years by the gravimetric method. The modified Durham sampler was applied, located at 9 m above ground level. On the base of results 6 year observations - the pollen calendar for Lublin was prepared. The following 15 plant taxa were taken under consideration: <i>Alnus</i>, <i>Corylus</i>, Cupressaceae, <i>Populus</i>, <i>Fraxinus</i>, <i>Betula</i>, <i>Quercus</i>, Pinaceae, Poaceae, <i>Rumex</i>, <i>Plantago</i>, <i>Urtica</i>, Chenopodiaceae, <i>Artemisia</i> and <i>Ambrosia</i>. The anemophilous plants' pollen season in Lublin began in half of February and lasted till half of September. First appeared pollen grains of decidous tress' and shrubs, then the coniferous. High values of pollen fall of these plants were noted till the end of May. Start of grass pollen season was recorded from the half of May, and at the latter part of this month, also other herbaceous plants. The highest concentrations of pollen were found in April and May when trees and shrubs pollinated. The highest annual totals were marked for plants of the following taxa: <i>Betula</i>, Poaceae, Pinaceae, <i>Alnus</i>, <i>Urtica</i>.