Dispersal of Septoria nodorum Pycnidiospores by Simulated Rain and Wind

The influence of wind on the splash dispersal of Septoria nodorum pycnidiospores was studied in a raintower/wind tunnel complex with single drops or simulated rain falling on spore suspensions or infected stubble with windspeeds of 1.5 to 4 m/sec. When single drops fell on spore suspensions (depth 0.5 mm, concentration 7.8 × 10⁵ spores/ml) most of the spore-carrying droplets collected on fixed photographic film between 0–4 m downwind (windspeed 3 m/sec) were >200 μm in diameter. However, most spores were carried in droplets with diameter > 1000 μm, 70 % of which carried more than 100 spores. When simulated rain fell on infected stubble most of the spore-carrying droplets collected beyond 1 m downwind (windspeeds 1.4 and 4 m/sec) were <200 μm in diameter and none were >600 μm; most of these droplets carried only one spore. The distribution of splash droplets (with diameter >100 μm) deposited on chromatography paper showed a maximum at 40–50 cm upwind of the target but many more droplets were deposited 20–30 cm downwind, when single drops fell on a spore suspension (concentration 1.2 × 10⁵ spores/ ml) containing fluorescein dye with a windspeed of 2 m/sec; droplets were collected up to 3 m downwind but not more than 70 cm upwind. With a windspeed of 3 m/sec, numbers of sporecarrying droplets and spores collected on film decreased with increasing distance downwind; most were collected within 2 m of the target but some were found up to 4 m. When simulated rain fell on infected stubble, increasing the windspeed from 1.5 to 4 m/sec greatly increased the number of spores deposited more than 1 m downwind. At 1.5 m/sec none were collected beyond 2 m downwind, whereas at 4 m/sec some were collected at 4 m. A few air-borne S. nodorum spores were collected by suction samplers at a height of 40 cm at distances up to 10 m downwind of a target spore suspension on which simulated rain fell.     

15. Brve (Czech Republic): Vegetation development over the last about 2.5 millennia in the Bohemian Lowland close to Prague

Two Burkard seven-day recording traps have been in operation in the cities of Johannesburg and Pretoria since 1987. Pollen calendars average data for 1987 and 1988. Grass pollen is the most significant contributor in absolute and relative terms. This taxon comprises 52% of total regional pollen for the study period. Pollen of alien northern hemisphere trees is abundant, relative to that of native trees. This is attributed partly to the paucity of trees in the natural vegetation, and partly to their entomophilous nature. The flowering season for exotics is very short, possibly due to the short spring season. The greatest proportion of pollen, 58,8%, is nonseasonal. Species in this category flower throughout the year. 28.4% of taxa are spring-flowering. Annual variability is marked for most taxa.     

Some components of the air spora in Jamaica and their possible medical application

A knowledge of the pollen and fungal spores which comprise the air spora is useful as a preliminary approach to the problem of respiratory allergy. Therefore, this study of the qualitative and quantitative aspects of the air spora was done. Fungal spores were found to be numerically dominant, comprising 97.73% whilst pollen comprised 0.40% of the total material observed. A small number of types made up the majority of the fungal air spora, namely, Cladosporium, the Sporobolomycetaceae group, Diatrype, Glomerella, hyaline and coloured basidiospores, and septate fusiform spores. Seasonal periodicity studies on twenty-five fungal types showed that a high number of spores were trapped for sixteen during wet months, four during cooler months, and that five showed no seasonal trends. Mean diurnal periodicity studies for the year on the same twenty-five spore types showed that all had a maximum number of spores trapped at some time during the day. Investigation of the effect of rainfall on the numbers of spores released showed that the amount and duration of rainfall, the time of day rain occurs, and the length of the dry period preceding rain were of varying importance to particular spore types.     

First results of a study on airborne sporomorps in Budapest,Hungary

The first results of an aerobiological study, with the help of a Burkard spore trap in Hungary, are reported. A pollen calendar of 1989 is presented. Out of the total identified sporomorphs, the most relevant 16 types of pollen and 10 of fungal spores are reported. We have pointed out, that in Budapest Ambrosia and Artemisia pollen and some fungal spores are particularly responsible for the long lasting allergies to pollen and spores in the autumn. The pollen frequencies and the symptom scores of patients of the Pediatrics (Semmelweis Medical School, Budapest) showed a good correlation. Weekly reports are published in a newspaper and in television.     

The aerobiological results from the 1994 cruise of the Urania (cnr) on the Adriatic. I. Pollen and spore counts on the Mediterranean sea as compared to mainland Italia

In July 1994, we were able to collect airborne fungal spores and pollen grains over the Adriatic Sea from the upper deck of the Oceanographic Ship Urania (CNR). The biological particles were collected using a modified Lanzoni VPPS 1000 sampler (operating at a flux of 10 LPM), on glycerine-gelatine coated microscopic slides. Not only were the airborne concentrations of different organisms estimated, their viability was also tested with a 1% TTC solution. Particles were collected for 60 min (i.e. a volume of 600 liters of air sampled) at every 2 h from 0600–2100 h. Up to 689 pollen grains/m³ and an impressive 48 990 spores/m³ were collected daily. Forty-two fungal taxa were identified and the most abundant spores collected were Cladosporium (82.6%), Smuts (4.8%), Ascospores (2.8%), Basidiospores (2.1%) andAlternaria (1.7%). 20 pollen taxa were identified, and the dominant pollen were Urticaceae (57.9%), Graminaceae (20.7%), Fagaceae (2.4%), Plantaginaceae (1.4%), Pinaceae (1.3%) and Eucalyptus (1.1%). The most abundant captures were done at 0800 and 1000 h (17.8 and 16.7% respectively) and at 1400 and 1600 h (13.2 and 13.8% respectively). Pollen viability per species ranged from 0 to 100%, but for the most abundant taxa, it ranged from 3.8 to 75%, and averaged 27.7%. Maximum viability was found at 0800 and 1200 h. Pollen concentrations were of the same order of magnitude as the ones found on the mainland (Brindisi, Chieti, Matera). However, its specificity was evident. Future work should therefore look more at the pollen transport process which should account for this different assemblage of pollen.     

The aerobiological results from the 1994 cruise of the Urania (cnr) on the Adriatic. I. Pollen and spore counts on the Mediterranean sea as compared to mainland Italia

In July 1994, we were able to collect airborne fungal spores and pollen grains over the Adriatic Sea from the upper deck of the Oceanographic Ship Urania (CNR). The biological particles were collected using a modified Lanzoni VPPS 1000 sampler (operating at a flux of 10 LPM), on glycerine-gelatine coated microscopic slides. Not only were the airborne concentrations of different organisms estimated, their viability was also tested with a 1% TTC solution. Particles were collected for 60 min (i.e. a volume of 600 liters of air sampled) at every 2 h from 0600–2100 h. Up to 689 pollen grains/m³ and an impressive 48 990 spores/m³ were collected daily. Forty-two fungal taxa were identified and the most abundant spores collected were Cladosporium (82.6%), Smuts (4.8%), Ascospores (2.8%), Basidiospores (2.1%) andAlternaria (1.7%). 20 pollen taxa were identified, and the dominant pollen were Urticaceae (57.9%), Graminaceae (20.7%), Fagaceae (2.4%), Plantaginaceae (1.4%), Pinaceae (1.3%) and Eucalyptus (1.1%). The most abundant captures were done at 0800 and 1000 h (17.8 and 16.7% respectively) and at 1400 and 1600 h (13.2 and 13.8% respectively). Pollen viability per species ranged from 0 to 100%, but for the most abundant taxa, it ranged from 3.8 to 75%, and averaged 27.7%. Maximum viability was found at 0800 and 1200 h. Pollen concentrations were of the same order of magnitude as the ones found on the mainland (Brindisi, Chieti, Matera). However, its specificity was evident. Future work should therefore look more at the pollen transport process which should account for this different assemblage of pollen.     

Characterizing Aeroallergens by Infrared Spectroscopy of Fungal Spores and Pollen

Background

Fungal spores and plant pollen cause respiratory diseases in susceptible individuals, such as asthma, allergic rhinitis and hypersensitivity pneumonitis. Aeroallergen monitoring networks are an important part of treatment strategies, but unfortunately traditional analysis is time consuming and expensive. We have explored the use of infrared spectroscopy of pollen and spores for an inexpensive and rapid characterization of aeroallergens.

Methodology

The study is based on measurement of spore and pollen samples by single reflectance attenuated total reflectance Fourier transform infrared spectroscopy (SR-ATR FTIR). The experimental set includes 71 spore (Basidiomycota) and 121 pollen (Pinales, Fagales and Poales) samples. Along with fresh basidiospores, the study has been conducted on the archived samples collected within the last 50 years.

Results

The spectroscopic-based methodology enables clear spectral differentiation between pollen and spores, as well as the separation of confamiliar and congeneric species. In addition, the analysis of the scattering signals inherent in the infrared spectra indicates that the FTIR methodology offers indirect estimation of morphology of pollen and spores. The analysis of fresh and archived spores shows that chemical composition of spores is well preserved even after decades of storage, including the characteristic taxonomy-related signals. Therefore, biochemical analysis of fungal spores by FTIR could provide economical, reliable and timely methodologies for improving fungal taxonomy, as well as for fungal identification and monitoring. This proof of principle study shows the potential for using FTIR as a rapid tool in aeroallergen studies. In addition, the presented method is ready to be immediately implemented in biological and ecological studies for direct measurement of pollen and spores from flowers and sporocarps.     

Diurnal variation of biological and non-biological particles in the atmosphere of Córdoba, Spain

In this work, the daily distribution of biological and non-biological particles in the atmosphere of the city of Córdoba, Spain, is analysed in order to know at what time of day the concentrations of solid suspended particles in the air is maximum. This knowledge can be useful for all those people who suffer of respiratory diseases and can help them to plan their outdoors activities. The concentrations of non-biological material have been estimated by using spectrophotometrical techniques. With this method, the amount of non-biological material is expressed in percentage of light absorbance in values oscillating from 0.00: absence of particles to 1.00: extreme presence of particles. As the absorption of light depends on the colour of the particle, it is also possible to distinguish dark particles (soot, diesel exhaust particles, sand) from hyaline or light coloured ones (pollen grains and several fungal spores types). The results have shown that the maximum peaks of material are achieved early in the mornings and late in the evenings. Aerobiological methodology has been used when dealing with material of biological origin. In this latter case, pollen grains and fungal spores have been differentiated from the rest of solid material. Due to their importance as agents causing pollen allergy in the area and the high percentage that they represent with respect to the total pollen spectrum, Olea europaea and grass pollen types have been differentiated from the rest of pollen types. The results show that the peaks of non-biological particles in the air throughout the day are related to the activities carried out by men in the city: commercial and working hours or social activities in the different seasons of the year. As regards the biological material, the pattern of fungal spores is clearly influenced by the climatic characteristics of the area, presenting the maximum concentrations in the late afternoon. The pollen grains follow a pattern coinciding with the diurnal maximum temperatures and sunshine hours. The values of the curve oscillate from 200 grains/m3 of air in night hours to maximum over 1000 grains/m3 at midday. The diurnal variation of Olea europaea is quite similar to this general pattern, presenting the maximum concentrations of pollen grains at central hours of day. The grasses show some differences due to the high number of species included in this family.     

Historic grazing in southern New England,USA, recorded by fungal spores in lake sediments

Decadal-scale analyses of fungal spores in a lake-sediment core from Ware Pond, located in the town of Marblehead in northeastern Massachusetts, test the potential of this approach for reconstructing past sheep and cattle grazing in southern New England, USA. The influx of spores of Sordaria and other coprophilous taxa increases at ad 1650, which corresponds with the beginning of European settlement, and subsequent peaks in these taxa at ad 1840 coincide with maximum abundances of weedy and agricultural taxa in the pollen record. Historical data from Marblehead and neighbouring towns indicate that maximum numbers of cattle and sheep occurred at this time. These findings suggest that fungal spores in New England lake sediments can be used to reconstruct changes in grazing pressure over time at the landscape scale.     

Airborne pollen and fungal spores in Garki,Abuja (North-Central Nigeria)

The ambient atmosphere is dominated with pollen and spores, which trigger allergic reactions and diseases and impact negatively on human health. A survey of pollen and fungal spores constituents of the atmosphere of Garki, Abuja (North-Central Nigeria) was carried out for 1 year (June 1, 2011–May 31, 2012). The aim of the study was to determine the prevalence and abundance of pollen and fungal spores in the atmosphere and their relationship with meteorological parameters. Airborne samples were trapped using modified Tauber-like pollen trap, and the recipient solutions were subjected to acetolysis. Results revealed the abundance of fungal spores, pollen, fern spores, algal cysts and diatoms in decreasing order of dominance. The atmosphere was qualitatively and quantitatively dominated by pollen during the period of late rainy/harmattan season than the rainy season. Numerous fungal spores were trapped throughout the sampling periods among which Alternaria spp., Fusarium spp., Cladosporium spp. and Curvularia spp. dominated. These fungi have been implicated in allergic diseases and are dermatophytic, causing diverse skin diseases. Other pathogenic fungi found in the studied aeroflora were Dreschlera spp., Helminthosporium spp., Torula spp., Pithomyces spp., Tetraploa spp., Nigrospora ssp., Spadicoides spp., Puccinia spp. and Erysiphe graminis. Total pollen and fungal spores counts do not show significant correlation with meteorological parameters.     

Status of airborne spores and pollen in a coir factory in Kerala,India

The prevalence of airborne fungal spores and pollen grains in the indoor and outdoor environments of a coir factory in Thiruvananthapuram district of Kerala state, India was studied using the Burkard Personal Sampler and the Andersen 2-stage Sampler for 2 years (September 1997 to August 1999). The concentration of pollen grains was remarkably lower than that of fungal spores (ratio of 1:28). There was no large difference in the concentrations and types of fungal spores between the indoor and outdoor environments, with 26 spore types found to be present indoors and 27 types outdoors; of these, 22 were common to both the environments. Aspergillus/Penicillium, Cladosporium, ‘other basidiospores’ and ascospores were the dominant spore types. The total spore concentration was highest in February and lowest in September, and it was significantly higher in 1998–1999 than in 1997–1998. Twenty viable colony-forming types were isolated from inside the coir factory. The most dominant viable fungi isolated were Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The total pollen concentration was higher in the outdoor environment of the coir factory than indoors, with 15 and 17 pollen types, respectively. Grass and Cocos nucifera pollen types were dominant. The dominant spore and pollen types trapped in the two environments of the coir factory are reportedly allergenic and, consequently, workers are at risk of catching respiratory/allergic diseases.     

Comparison of diurnal variation of airborne pollen in Mar del Plata (Argentina)

Intradiurnal variation of arboreal pollen (AP) in Mar del Plata city is compared during three non - consecutive years of survey and described in relation to the associated weather. The daily pattern of pollen abundance has a maximum between 10:00 and 12:00?h, while a minimum occurs at 18:00?h. The first two years of survey showed homogeneous daily trends, but in 1995 the maximum and minimum concentrations were delayed because of the change in position of the collecting station. Arboreal pollen spectrum presented qualitative and quantitative changes in the three years analysed. Results indicate optimal conditions for diurnal dispersion of arboreal pollen are high temperatures and low relative humidity. Also interaction between source position and wind direction has important effects on the timing of the peaks of some pollen types.     

Gamma,Gaussian and logistic distribution models for airborne pollen grains and fungal spore season dynamics

The characteristics of a pollen season, such as timing and magnitude, depend on a number of factors such as the biology of the plant and environmental conditions. The main aim of this study was to develop mathematical models that explain dynamics in atmospheric concentrations of pollen and fungal spores recorded in Rzeszów (SE Poland) in 2000–2002. Plant taxa with different characteristics in the timing, duration and curve of their pollen seasons, as well as several fungal taxa were selected for this analysis. Gaussian, gamma and logistic distribution models were examined, and their effectiveness in describing the occurrence of airborne pollen and fungal spores was compared. The Gaussian and differential logistic models were very good at describing pollen seasons with just one peak. These are typically for pollen types with just one dominant species in the flora and when the weather, in particular temperature, is stable during the pollination period. Based on s parameter of the Gaussian function, the dates of the main pollen season can be defined. In spite of the fact that seasonal curves are often characterised by positive skewness, the model based on the gamma distribution proved not to be very effective.     

A year-round study on functional relationships of airborne fungi with meteorological factors

Air sampling was conducted in Waterloo, Canada throughout 1992. Functional relationships between aeromycota and meteorological factors were analysed. The meteorological factors were, in descending order of importance: mean temperature, minimum temperature, maximum temperature, mean wind speed, relative humidity (RH), rain, maximum wind speed and snow. The most important airborne fungal propagules in descending order were: total fungal spores, unidentified Ascomycetes,Cladosporium, Coprinus, unidentified Basidiomycetes,Alternaria and unidentified fungi. Most airborne fungal taxa had highly significant relationship with temperature, butAspergillus/Penicillium, hyphal fragments andEpicoccum did not.Epicoccum and hyphal fragments were positively associated with wind speed. In comparison with other airborne fungal taxa,Leptosphaeria and unidentified Ascomycetes were more closely correlated with rain and RH during the growing season.     

Survey of aerospora by Rotorod Sampler in Lucknow, India: qualitative and quantitative assessment

The monitoring of airborne pollen and fungal spores ofLucknow has been achieved using a Rotorod Sampler. 43types of pollen and 40 types of fungal spores havebeen recorded over a period of one year(January–December, 1997). Pollen and fungal sporecalendars have been constructed. Quantification of theaerospora will help in further understanding aeroallergens and the diagnosis and treatment ofvarious respiratory diseases.     

Gut contents in field sampled adults ofCoccinella septempunctata (Col.: Coccinellidae)

During two years adultCoccinella septempunctata L. were sampled at two localities in cereals and at another location throughout the whole year in different habitats. Frequency of different food types was recorded using gut dissection. Food remains were classified into aphids, other arthropods, fungal spores, pollen, soil particles. Soil particles were relatively frequent only in early spring and pollen in late summer, whereas fungal spores were most frequent in both these periods. During ladybird reproduction in winter wheat, aphid remains were present in 76.9–91.7% of all individuals and surprisingly spores were again more frequent than remains of other arthropods. Cannibalism was rare. Food ofC. septempunctata was very uniform, because nearly always the same spores (Alternaria sp.) and other arthropods (Thysanoptera) were found. Additionally a semiquantitative analysis was performed with a simple scale of gut fullness. Only in certain cases significant positive correlation were determined between aphid density in the field and the calculated “feeding state” as well as frequency of aphid remains.     

Performance of the Coriolis air sampler,a high-volume aerosol-collection system for quantification of airborne spores and pollen grains

The Coriolis δ air sampler manufactured by Bertin Technologies (France) is a continuous air sampler, dedicated to outdoor monitoring of airborne spores and pollen grains. This high-volume sampler is based on patented Coriolis technology delivering a liquid sample. The air is drawn into a conical vial in a whirling type motion using suction; particles are pulled against the wall by centrifugal force. Airborne particles are separated from the air and collected in a liquid medium. This innovative solution allows rapid analysis by several techniques including PCR assay and serological assay in order to measure the antigenicity/allergenicity of pollen grains and fungal spores. Also, traditional counting of pollen grains or taxa identification by optical microscopy can be done. A study has been carried out by the Health Protection Agency (HPA), Porton Down, UK, to measure the physical efficiency of the Coriolis air sampler. The physical efficiency of the sampler for collection of micro-organism-laden particles of various sizes has been compared with that of membrane filter samplers using the techniques described by ISO 14698-1. The Coriolis was operated simultaneously with membrane filter samplers in a controlled room where they were challenged with uniform-sized particles of different diameters containing bacterial spores. For the larger particle sizes, it was found that the physical efficiency of the Coriolis was 92% for 10-μm particles. The biological performance of the Coriolis in the collection of airborne fungal spores and pollen grains was evaluated in comparison with a Hirst spore trap (one-week tape-on-drum type sampler) which is one of the most frequently used traps in the measurement of outdoor pollen grain concentrations. The advantages and limitations of both technologies are discussed. The Coriolis was operated simultaneously with a Hirst spore trap in the sampling station of Réseau National de Surveillance Aérobiologique, France (RNSA); the pollen grain and fungal spore counts were analysed by optical microscopy. The pollen grain count m⁻³ collected was compared for both devices. The dispersion values were obtained and statistical analysis was carried out. This study shows that the Coriolis air sampler provided equivalent recovery of pollen grain and fungal spores compared with the volumetric trap standard method (not significantly different, W test, α = 0.05). Nowadays, the French-led project, acronym MONALISA, with financial support from the European Commission––Life-Environment (LIFE05 ENV/F/000068), is testing this innovative air sampler in order to measure the antigenicity/allergenicity of the main aeroallergen particles, i.e. Betula (birch), Poaceae (grasses), Parietaria (pellitory), Olea spp (olive tree), and Artemisia (mugwort) pollen grains, and Alternaria (fungal spores) to validate a new approach of monitoring instead of quantifying pollen grains by their morphology. The robustness and efficiency of the MONALISA system is being demonstrated at a national level throughout Europe in eight different countries with different bio-climatic and topography characteristics: France, UK, Finland, Poland, Spain, Portugal, Switzerland, and Italy.     

Airborne pollen and spores on the Arctic island of Jan Mayen

A survey of airspora collected on Jan Mayen, an isolated North Atlantic island (71°N, 8°30′W), using a Burkard seven-day volumetric trap from 24th April to 31th August, 1988, revealed only very small concentrations. A total of 10 different pollen types were recorded, constituting a seasonal sum of 29 pollen grains. The local pollen season was confined to July, with Oxyria digna and Salix as the most numerous pollen types recorded. Exotic pollen grains, namely Betula, Pinus and Castanea type, were recorded in three periods during June and July. Studies of back trajectories indicate North America and/or Iceland and Greenland as possible source areas for the Betula pollen. There were more diatoms than pollen in the local airspora. Fungal spores mainly occurred in late July and August. Cladosporium constituted less than 5% of the total seasonal sum of fungal spores, while basidiospores contributed nearly 12%. The highest diurnal average of Cladosporium was 27 spores m^?3 air. The seasonal maximum of unidentified fungal spores reached a diurnal average of 639 spores m^?1 air on 27th August.     

The variation in spore concentrations of selected fungal taxa associated with weather conditions in Szczecin,Poland, 2004–2006

The investigation of airborne fungal spore concentrations was carried out in Szczecin, Poland between 2004 and 2006. The objective of the studies was to determine a seasonal variation in concentrations of selected fungal spore types due to meteorological parameters. The presence of spores of ten taxa: Cladosporium, Ganoderma, Alternaria, Epicoccum, Didymella, Torula, Dreschlera‐type, Polythrincium, Stemphylium and Pithomyces was recorded in Szczecin using a volumetric method (Hirst type). Fungal spores were present in the air in large numbers in summer. The highest concentrations were noted in June, July and August. The peak period was recorded in August for most of the studied spore types: Ganoderma, Alternaria, Epicoccum, Dreschlera‐type, Polythrincium and Stemphylium. Cladosporium and Didymella spores reached their highest concentrations in July while concentrations of Torula were highest in May and Pithomyces in September. Multiple regression analysis was performed for three fungal seasons: 2004, 2005, and 2006. Spore concentrations were positively correlated with minimum temperature for seven spore types in 2004, for five spore types in 2005, and for eight spore types in 2006 (significance level of α = 0.05). Some spore types are also significantly correlation among their concentrations, pressure, relative humidity and rain. Minimum temperature appeared to be the most influential factor for most spore types.     

A 3-year airborne pollen and fungal spores record in San Carlos de Bariloche, Patagonia, Argentina

Airborne pollen in San Carlos de Bariloche was sampled from September to March 2001–2004 with a Hirst-type volumetric spore trap placed at a height of 15 m in a city extending from the humid forests, through the mesic forests, to the steppe. The total amount of pollen recorded varied widely from year to year. The pollen index was 4,395 in the sampling period 2001/2002; 9,055 in 2002/2003 and 2,756 in 2003/2004. The main pollen period extended from October to January. In October, pollen concentration was the highest. Sixty-six pollen types were identified. Cupressaceae and Nothofagus were the major contributors. Betula, Prunus, Pinus and Populus, the most abundant ornamental taxa in the city, also contributed to the pollen record. Pollen of Maytenus and Lomatia was representative of the mesic forest, while pollen in the lower layers of the humid forest was present in trace amounts. Cupressaceae, Nothofagus and Betula prevailed during spring (September–December), and Plantago, Rumex and Poaceae during summer (December–March). The association of daily pollen concentration and meteorological variables, temperature (mean, maximum, minimum), dew point, rainfall and wind speed, was significant. Correlations showed to be negative, with the exception of that to wind speed. The total sum of fungi spores increased from 1,771 in 2001/2002; through 8,441 in 2002/2003 to 13,782 in 2003/2004. Relative concentration rose to 29%, 48% and 84% of the total number of pollen and fungal spores recorded during each sampling period.