The results of 2-year pollen monitoring of an urban network in Perugia,Central Italy

Continuous pollen monitoring of an urban network consisting of three stations has been undertaken for a period of 2 years in Perugia, central Italy. The aim has been to establish whether the Perugia pollen trap, active since 1983, is still representative of the area following recent urbanisation. Quantitative differences were found between the stations, reflecting different vegetational areas, but only slight differences were detected in relation to the timing of the principal period of pollination. Therefore, although individual pollen traps are necessary to characterize fully the different areas, one trap is sufficient to determine the key allergenic thresholds in the studied area.     

One year of pollen monitoring in an urban network,perugia, central italy

Pollen monitoring at three locations in the area of Perugia is reported for the period November 1988-October 1989. A meteorological station which automatically provided data (temperature, precipitation, relative humidity, direction and velocity of wind), was located beside each trap. The study was correlated with a phenological investigation in urban and rural areas surrounding the traps in order to test the validity of using the results as indicators in a monitoring network. The aerobiological data of the three monitoring stations allows the following conclusions: 1) no notable differences were recorded during the principal period of pollination considering the flowering trends of the local anemophilous flora are taking into account, 2) from a quantitative point of view, values from Central Perugia and West Perugia were higher than those from East Perugia, 3) from a qualitative point of view, the station located in the old city area was characterized by a significant presence of Urticaceae pollen, while pollen of the Gramineae was prevalent in the two stations located in the recently built areas.     

An integrated use of aerobiological and phenological data to analyse flowering in olive groves

Aerobiological and phenological investigation has been linked to analyse the flowering phenomena of olive (Olea europaea L.), a tree of economic importance, in Umbria, central Italy.

Olive tree flowering was analysed by phenological observations in olive groves. Aerobiological monitoring was carried out with pollen traps that captured the pollen grains in the atmosphere by remote distances. This combined study of flowering was useful in overcoming the principal limit of phenological observations caused by their geographical narrowness.

Eleven phenological stations in Perugia province were used and periodic observations were carried out during the flowering season. Two aerobiological stations located near the cities of Perugia and Spoleto were utilized to trap olive pollen grains in the atmosphere.

Graphic and statistical analyses were used in order to study flowering dynamics, and to compare the methodological approaches.

The phenological areas, according to their characteristics, were divided in two clusters each one related to a different pollen monitoring station. Statistical analyses showed the presence of a three ‐ four‐day period during which pollen released in the groves is persistent in the narrowness and resulted in a high correlation with the pollen monitored by the pollen traps. On the other hand, the phenological data considered along with the daily pollen concentrations permit the pollen peaks to be attributed to particular olive areas or olive cultivars. This demonstrates that both methodologies can be used effectively as integrated research tools in this kind of study.     

Aeropalynological and phenological study in two different Mediterranean olive areas: Cordoba (Spain) and Perugia (Italy)

ABSTRACT

An aerobiological and phenological investigation on the olive tree was carried out during three years in two areas: Cordoba (Spain) and Perugia (Italy). In these countries, this species is economically important and those areas were chosen because of the long series of aeropalynological data (1982–1998) available, obtained by means of identical volumetric pollen traps. The aim of this study was to use phenological observations to prove the real contribution to the pollen curves in different cultivated areas. Results show that in Cordoba province (302.152 ha) the pollen curve is characterised by different peaks because of the pollination of different cultivated crops. In some cases, these crops are located far from the pollen trap (50 km) but pollen is transported thanks to favourable winds during the flowering period. In Perugia (750 ha) the pollen curve is characterised by only one peak; it is very concentrated because of the proximity of the investigated crops. The objective of this research was to obtain information on this species in order to elaborate statistical models aimed at forecasting the potential fruit production based on the amount of pollen released into the atmosphere.     

Temperature requirements of Alnus pollen in Spain and Italy (1994-1998)

Woody plants in temperate regions, in order to prevent the water in their cells from freezing, interrupt their growth entering into a physiological state called "dormancy". Trees also have a heat requirement that must be fullfilled before actual growth is resumed and pollination occurs. The objective of this study is to ascertain the influence that a climatic parameter such as temperature exerts on Alnus, in order to identify the start of the dormancy period, its duration and the consequent heat requirement that triggers flowering in three European regions located at the same latitude. In this regard, we chose two areas in Spain (Vigo and Santiago de Compostela) and one in Italy (Perugia), since they have different temperature patterns, ranging from mild in the case of Vigo to cold in that of Perugia, including an intermediate temperature pattern (Santiago). Monitoring in the three stations was carried out by means of a 7-day Lanzoni VPPS 2000 pollen trap. Alnus began its pollen season between the second and third week of January in Spain, while in Italy it began during the first week of February. During the four years under study, in order to overcome the dormancy period, Perugia needed an average of 962 chilling hours (CH), Santiago 622 CH, and Vigo had the smallest chilling accumulation with only 460 CH. In the case of heat accumulation, we found that Perugia had the smallest requirement and Vigo the largest, thus Perugia needed an average of 42 (growth degree days) GDD, Santiago around 50 GDD and Vigo 62 GDD.     

Differences in atmospheric trees pollen seasons in winter, spring and summer in two European geographic areas, Spain and Italy

The global climate change reported over recent years may prompt changes in the atmospheric pollen season (APS). The aim of this study is to evaluate the possible impact provoked by meteorological conditions variations at different seasons of the year or different geographical areas on APS. Alnus, Betula and Castanea atmospheric pollen seasons and trends during the last 17 years at Ourense and Vigo (Galicia—NW Spain) and Perugia (Italy) were analysed. Possible incidence of the meteorological trends observed in the different cities on the atmospheric pollen seasons and the chill and heat requirements were evaluated. Pollen data from Ourense, Vigo and Perugia (1995–2011) were used. Pollen sampling was performed using LANZONI VPPS 2000 volumetric traps (Hirst in Ann Appl Biol 36:257–265, 1952), placed on top of different buildings at a similar height from the ground. Several methods, dates and threshold temperatures for determining the chill and heat requirements needed to trigger flowering were tested. Different temporary order in the pollination sequence was observed between the three pollen types studied in the three sites. Alnus flowers few days in advance in Ourense respecting to Vigo and 1 month earlier than Perugia. The Betula flowering start date in Ourense and Vigo is almost simultaneous, taking place only 5 days in advance with respect to Perugia. Finally, scarce differences in the APS onset of Castanea were detected between the three cities. The variations observed among the two areas (Umbria, Italy and Galicia, Spain) in the onset of pollen season in the winter or spring flowering trees could be explained by differences in the thermal requirements needed for flowering as consequence of the climatic conditions recorded during the previous period to flowering. The length of the chilling and heat period as well as the thermal requirements obtained showed differences between geographical areas. The chill requirements accumulated were higher in Perugia than Ourense and Vigo. By contrary, the lowest heat accumulation was achieved in Perugia. The observed trends in the APS characteristics and the weather-related parameters were not homogeneous both in the pollen types and sites. The pollen index of Betula and Castanea pollen in Ourense shows a significant trend to increase.     

The influence of climate changes in Platanus spp. pollination in Spain and Italy

There is evidence of a significant increase in air temperature in the northern hemisphere over recent decades, with consequent changes for anemophilous pollen. In this work we present the effects of climatic change on Platanus spp. pollination in different areas of Italy and Spain, characterized by different climates. In particular, the historical series of pollen monitoring and meteorological data of two Italian stations, Perugia (1982 – 2003) and Torino (1985 – 2003), and two Spanish stations, Santiago de Compostela (1992 – 2003) and Vigo (1994 – 2003), were analysed. The changes recorded in all stations included the timing and behaviour of pollen release. However, no or minimal influence on the total pollen emission was found. Research has linked the changes in phenological events to an increase in temperature, moreover in this study temperature changes are believed to be mainly responsible for the variations recorded in the pollen season of Platanus. A previous start of pollination (?0.66; ?1.21; days/year) is reported in both Italian stations where the temperatures have significantly increased and a delay of 0.2 – 0.8 days/year in Spanish stations where a different trend of temperature is recorded. Other important data is given regarding the type of discharge of pollen grains during the pollen season. Pollination curves are examined by two statistical shape parameters (kurtosis and skewness) which show that pollen release is more gradual with higher temperatures or faster under colder conditions. A regression analysis links the atmospheric pollen presence to mean air temperature.     

Time linkages between pollination onsets of different taxa over an 11-year period in Perugia,Central Italy

Times of pollination of different taxa in the atmosphere of Perugia (Central Italy) over an 11-year period (1982–1992) were recorded and analysed by means of a 7-day volumetric Hirst-type pollen trap. For some taxa, the pollination period varied from year to year from a chronological and/or quantitative point of view. Several taxa showed a linkage in their starting dates of pollination. Knowledge of this kind of linkage allows us to build a forecasting model.     

Fluctuations of grass pollen content in the atmosphere of East Perugia and meteorological correlations (year 1989)

Summary Gramineae pollination from a pollen monitoring station located in the eastern suburb of Perugia and meteorological correlations are reported. The data refers to the year 1989. Grass pollen peak pollination was from May to July; in this period the influence of relative humidity and of temperature on pollen concentration was very high. Phenological observations, to identify the time of maximum stamen extension in the most common genera in the area, are also reported. During the period of investigation the counts of pollen grains over four-hour periods showed a regular diurnal rhythm with peaks of concentration in the four-hour period 16.00–20.00. Aerosporological data and meteorological data related to four-hour periods were correlated following different criteria.     

Pollen monitoring in Perugia and information about aerobiological data

Summary The results of six years (1982–1987) of aerobiological study in Perugia (central Italy) are reported. During this period a total of 80 different types of pollen belonging to 52 families were identified in the Perugia atmosphere. The highest percentages of pollens were found in the mid-March to mid-July period. For main taxa principal periods of pollination were identified. The outlines for the weekly issue in a newspaper of the concentration pattern of the allergenic pollens are reported.     

Spatial distribution of pollen-induced symptoms within a large metropolitan area—Berlin,Germany

Large spatial differences in the distribution of three allergologically relevant pollen types for Central Europe—birch, grass, and mugwort—are revealed within a large metropolitan area—Berlin, Germany. The purpose of the study is an examination of the hypothesis that these different pollen exposure conditions can cause different degrees of pollen-induced symptoms within the city. Pollen data from 14 gravimetric traps and one volumetric trap in Berlin and anonymously reported pollen-induced symptom data from the online-based self-documentation tool “Patient’s Hayfever Diary” (PHD) are used for the analysis of temporal and spatial variations of the severity of the overall total symptoms. Geographically localised symptom data are linked to the nearest pollen trap. Statistical analysis is performed using Kendall’s Tau-b. Higher amounts of monitored birch and grass pollen in the peripheral areas of Berlin induce stronger symptoms in PHD users located within suburbs than those located in the city centre. There is no statistical relationship between the varying presence of mugwort pollen in the air and the severity of symptoms. Spatial differences in the pollen-induced symptom severity within a large city coinciding with spatial differences in birch and grass pollen depositions are shown for the first time. Therefore, pollen data from a single trap may not provide an appropriate explanation for differences in pollen-induced symptoms across the city. More detailed and reliable information about the exposure to allergenic pollen can be addressed by installing further traps in order to improve the knowledge about pollen exposure within cities.     

Phenological analysis of grasses (Poaceae) as a support for the dissection of their pollen season in Perugia (Central Italy)

Grasses (Poaceae) pollen is a major cause for allergic diseases worldwide. Pollen monitoring in the atmosphere is of primary importance for symptoms interpretation and therapy planning. Microscopic pollen identification and counts do not allow the detection at species or genus level because of the stenopalynous nature of the family. Nevertheless, the assessment of the flowering phenology of different species would be important, because not all grass allergens are cross-reacting and allergic patients could be differentially sensitized. In this work, a phenological survey was carried out in five stations located on the urban territory of Perugia (Central Italy), from April to September 2015, recording the alternation between flowering phenophases of 19 grass species and estimating their contribution to the airborne pollen load of the area through the calculation of a Phenological Index. Moreover, pollen grains of the different species were collected and observed, confirming the impossibility to make a discrimination during microscope pollen counts. The prevailing grasses in terms of contribution to the pollen detection in the studied area resulted to be Dactylis glomerata and Lolium perenne during spring and early summer, and Cynodon dactylon during late summer. Data should be validated repeating the survey in successive years and possibly using biomolecular tools, but the obtained information could be relevant for diagnosis and treatment of grass pollen allergies.     

Pollen concentrations in central Italy (Ascoli Piceno and Perugia)

Summary Air-borne pollen grains were collected using Hirst volumetric spore traps in both Ascoli Piceno and Perugia during the March–November 1983 period. Similar types of pollens were recorded in both towns. In Perugia, higher total amounts of Cupressaceae/Taxaceae pollens were recorded in March and of Quercus, Gramineae, Urticaceae and Oleaceae in May–June. However, the pollen concentration in the Ascoli Piceno atmosphere was higher in the August–October period owing to the pollen of the ?summer weeds?.

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Riassunto I granuli di polline aerodiffusi sono stati campionati con trappole volumetriche tipo Hirst sia in Ascoli Piceno che in Perugia durante il periodo marzo–novembre 1983. In entrambe le città sono stati rilevati tipi di polline simili. In Perugia sono state registrate concentrazioni di polline in atmosfera più elevate rispetto ad Ascoli Piceno in marzo per la pollinazione di Cupressaceae/Taxaceae e in maggio–giugno per la pollinazione di Quercus, Gramineae, Urticaceae e Oleaceae. In Ascoli Piceno, invece, la concentrazione di polline in atmosfera è state più elevata di Perugia nel periodo agosto–ottobre per la pollinazione delle ?erbe estive?.

     

Airborne-pollen map for Olea europaea L. in eastern Andalusia (Spain) using GIS: Estimation models

Estimations based upon geostatistics and mapping have enabled the construction of a spatial model to predict the presence of biological particles in a particular region. This methodological proposal has been tested in a case study, at a regional scale, of airborne Olea pollen, using the data acquired from␣various sampling stations that are designed for the aerobiological monitoring of pollen levels. These sampling stations have been set up in cities throughout the region of Andalusia (southern Spain) at sites with very different characteristics in terms of biogeography, bioclimate, topography and vegetation. Pollen counts were made daily at all sites during 2003 using a volumetric spore-trap. Data were comparatively analysed in classical diagrams and by means of spatial-temporal maps. Space-time models were constructed using three coordinates, x, y (the UTM coordinates of each sampling station) and z, (the aerobiological data compiled for a specific period). The aerobiological data were interpolated by applying the traditional geostatistical method of Kriging. The introduction of the variable “space” into the model allowed us to predict pollen levels in different areas throughout the region. The interpolation method was used to make weekly estimations of Olea pollen values in areas where there was no aerobiological sampling station. In addition, the maps generated present a two-dimensional vision of the study area, showing that bioclimatic diversity of this region promotes a step-wise flowering of Olea.     

Results of three years of aerobiological sampling in the atmosphere of Busto Arsizio

Summary The Compositae rarely cause respiratory allergy, but in our area located North-West of Milan, symptoms of sensitization appear with ever increasing frequency and are wide-spread. The importance of the pollination of Ragweed has been documented thanks to aerobiological sampling carried over a period of three years, using a pollen trap (Lanzoni VPPS 2000) and collecting weekly data.The results show that the Ragweed pollen is present as from mid July and that the highest pollen concentration is found at the end of August (1988: 125 grains/m³ of air; 1989: 289 grains/m³ of air; 1990: 378 grains/m³ of air).It is possible to find a significant quantity of pollen until the first days of October. Because of the allergological importance of Ragweed, it is advisable that the stations of aerobiological sampling consider Ragweed pollen much more carefully and carry out the pollen count of Ragweed separately from that of the other Compositae. We would also advise that Ragweed be included in the standard Skin-Prick-Test panel for patients with late-summer allergy symptoms.     

Relationship between pollen emission and fruit production in olive (Olea europaea L.)

Aerobiological data of pollen emission concentrations is used to predict fruit production. The principal aim of this work was to study the relationship between pollen emission patterns, emission homogeneity and fruit production in olive (Olea europaea L.). Data of daily pollen concentrations in the atmosphere during the flowering period, collected over a 20‐year period in Perugia (Central Italy), and the corresponding fruit production data were analysed. Correlation and regression analyses on the partial pollen amounts (subdivisions of the whole flowering period), their statistical variability (expressed as coefficients of variation of the daily pollen concentration), and the production values in the different years demonstrate that pollen emission, during the seven to ten day period immediately preceding the maximum pollen emission day, appears to be most closely related to fruit production. Moreover, the pollen emission homogeneity (minimal variability in daily pollen concentrations) during the “critical” flowering period is very important for fertilization.     

Forecasting airborne Platanus pollen in the Madrid region

This study analyses the atmospheric concentration of Platanus pollen in four stations in the Madrid region over a period of 10 years (1994–2003). Various statistical analyses (regression analysis and decision tree) were used to prepare a forecasting model for possible application as a preventive measure in pollinosis. The data comes from the PALINOCAM network and the samplers used were Hirst type (Burkard pollen trap). Platanus pollen is present in the atmosphere during a short period of time in spring, and the maximum concentrations are detected during the last two weeks of March and the first week of April. Regression analysis shows that the pollen concentration of the two previous days is the best predictive variable. The models obtained for the four stations analysed account for between 37 and 61% of the variation in pollen levels in the air. The decision trees show how the introduction of meteorological variables improves prediction for this pollen type.     

南京低山丘陵区表土及捕捉器花粉谱的差异探究

选取南京丘陵地区29处样点,分别搜集表土及捕捉器样品,开展两种采样方式下孢粉组合与植被关系研究。结果表明,南京低山丘陵地区花粉类型以松属、栎属、枫杨属、榆属、蔷薇科、菊科、禾本科为主,表土花粉组合较好地反映了现代植被特征。主成分分析可以大致区分人工草坪区、农田区以及森林区的样品。农田区表土花粉浓度最低,每克仅为4 964粒,农田的翻耕以及微生物环境是造成其花粉浓度低的重要原因;森林区花粉浓度(每克29 176粒)及花粉通量(49 358粒/平方厘米/年)均很高。人类活动的增强可能会造成孢粉浓度的下降。在探究本地区历史时期人类活动时,可运用孢粉浓度以及与农作物相关的孢粉类型的变化来分析。所有捕捉器样品的乔木花粉百分比均低于其对应的表土样品,其中以松属尤为明显。     

Correlation between large-scale atmospheric fields and the olive pollen season in Central Italy

Olives are one of the largest crops in the Mediterranean and in central and southern Italy. This work investigates the correlation of the Olea europaea L. pollen season in Perugia, the capital city of the region of Umbria in central Italy, with atmospheric parameters. The aim of the study is twofold. First, we study the correlation between the pollen season and the surface air temperature of the spring and late spring in Perugia. Second, the correlation between the pollen season and large-scale atmospheric patterns is investigated. The average surface temperature in the spring and late spring has a clear impact on the pollen season in Perugia. Years with higher average temperatures have an earlier onset of the pollen season. In particular, a 1°C higher (lower) average surface temperature corresponds to an earlier (later) start of the pollen season of about 1 week. The correlation between the pollen season and large-scale atmospheric patterns of sea level pressure and 500-hPa geopotential height shows that the cyclonic activity in the Mediterranean is unequivocally tied to the pollen season in Perugia. A larger than average cyclonic activity in the Mediterranean Basin corresponds to a later than average pollen season. Larger than average cyclonic activity in Northern Europe and Siberia corresponds to an earlier than average pollen season. A possible explanation of this correlation, that needs further investigation to be proven, is given. These results can have a practical application by using the seasonal forecast of atmospheric general circulation models.     

A satellite-based map of onset of birch (<Emphasis Type="Italic">Betula</Emphasis>) flowering in Norway

Birch (Betula pubescens L.) is by far the most common deciduous tree in Norway and birch forests define the forest line both northwards and upwards. Because of its mountainous topography, long fjords, and long length from north to south, Norway is climatically and ecologically very diverse. Therefore, developing pollen forecasts in Norway is a challenging task. In this study we use MODIS-NDVI (normalized difference vegetation index) satellite data with 250 m spatial resolution and 16-days time resolution for the period 2000–2007, and birch pollen counts from ten Burkad traps distributed throughout Norway, to characterize the onset of birch flowering in Norway. Four of the seven trap stations with long-term series show significant values at the 5% level or better between the MODIS-NDVI defined onset and the date when the annual accumulated birch pollen sum reaches 2.5% of the annual total. A map of Norway that shows the eight-year mean (2000–2007) onset of birch flowering was produced. It reveals large differences in the timing of the onset of birch flowering along the north–south and altitude gradients. The map provides useful general information that can be utilized by the Norwegian pollen forecast service. This study shows that remote sensing is a useful tool for not only characterizing the onset of the birch pollen season but also revealing regional differences not easily detected by pollen stations alone.