Effects of meteorological parameters and plantdistribution on Chenopodiaceae-Amaranthaceae, Quercus and Olea airborne pollen concentrationsin the atmosphere of Cartagena (Spain)

We have studied the effects of various meteorologicalparameters and plant distribution on the airborneconcentrations of three different pollen types:Chenopodiaceae-Amaranthaceae, Quercus and Olea, in the city of Cartagena, situated in SouthwestEurope. The aerobiological study has been carried outfrom March 1993 to March 1997, using a Hirst-typeLanzoni 2000 trap, situated on the roof of the citytrain station. Meteorological data were supplied bythe Environmental Service of Cartagena's Town Hall.Daily pollen concentrations were standardised.Correlation analysis showed the importance ofmeteorological data on airborne pollen concentrations.On the other hand, ANOVA analyses depicted theinfluence of vegetation distribution in relation tosampler location and wind directions. Finally,multiple regression analyses allowed us to developcorrelation models for the three different pollentypes considered, accounting for 32%(Chenopodiaceae-Amaranthaceae), 19% (Quercus),and 26% (Olea) of the variation in the airbornepollen concentration.     

Influence of meteorological parameters on Olea flowering date and airborne pollen concentration in four regions of Portugal

For calculating the total annual Olea pollen concentration, the onset of the main pollen season and the peak pollen concentration dates, using data from 1998 to 2004, predictive models were developed using multiple regression analysis. Four Portuguese regions were studied: Reguengos de Monsaraz, Valença do Douro, Braga and Elvas. The effect of some meteorological parameters such as temperature and precipitation on Olea spatial and temporal airborne pollen distribution was studied. The best correlations were found when only the pre‐peak period was used, with thermal parameters (maximum temperature) showing the highest correlation with airborne pollen distribution. Independent variables, selected by regression analysis for the predictive models, with the greatest influence on the Olea main pollen season features were accumulated number of days with rain and rainfall in the previous autumn, and temperatures (average and minimum) from January through March. The models predict 59 to 99% of the total airborne pollen concentration recorded and the initial and peak concentration dates of the main Olea pollen season.     

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.     

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.     

Oleaceae in Trieste (NE Italy): aerobiological and clinical data

Oleaceae pollen concentrations in the Trieste area are low (<10%) compared to the total number of airborne pollen grains, with only one pollination peak at the beginning of June when the Oleaceae concentration reached 62% of the total pollen count in 1992. This peak was due to an exceptionally high pollination of olive trees in 1992, when airborne pollen concentration rose to 1357 pollen grains/m³ on June 3. Sensitization toOlea increased from 1989 to 1993, when it was present in 23.4% of symptomatic patients, but the role ofOlea in inducing allergic respiratory symptoms is difficult to evaluate because almost all patients were sensitized to other pollens, and in particular to Gramineae: only four subjects were sensitized toOlea alone (1.4%). Despite the low Oleaceae pollen counts, this pollinosis is increasing, probably because of increased cultivation ofOlea in recent years. However, although skin prick test positivity is common in polysensitized patients, its role in inducing sensitization and symptoms is presently less important than that of other pollens.     

Variations in airborne pollen in central and south-western Spain in relation to the distribution of potential sources

The present study seeks to compare daily and hourly airborne pollen concentrations at eight different stations in Castilla-La Mancha (central Spain) and Extremadura (south-western Spain) and assess pollen distribution sources. Sampling stations were located 69–440 km apart in a straight line in Albacete, Toledo, Talavera de la Reina and Ciudad Real in Castilla-La Mancha, and in Badajoz, Plasencia, Santa Amalia and Zafra in Extremadura. Airborne pollen was collected using Hirst-type volumetric spore traps. Quercus was the most abundant pollen type at all stations except for Ciudad Real, where Olea pollen predominated. Comparisons of daily data between pairs of stations revealed statistically significant positive correlations in all cases for Poaceae and Olea. Comparisons of hourly data between stations indicated greater differences than daily data. Analysis of correlation coefficients and straight-line distances between stations revealed a strong negative correlation. Analysis of total airborne pollen data for the eight sampling stations suggests that airborne pollen concentrations decrease from west to east and from south to north, partly reflecting dominant wind patterns. A clear correlation was observed between airborne pollen concentrations and the surface area covered by olive crops in a 50 km radius around the sampling stations.     

In Memoriam Siwert Nilsson 1933–2002

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

Aprpaoches to airborne pollen in SE spain. First survey in murcia: one year of pollen monitoring (1993–94)

First data from a pollen survey carried out in the city of Murcia (SE Spain) are given in this paper. Using a Burkard Volumetric Spore Trap, daily slides were prepared and 80 pollen types belonging to 51 families andAlternaria spores were identified and counted. Special attention was paid to 14 relevant taxa: Cupressaceae,Pinus, Genisteae,Olea, Morus, Acer, Platanus, Plantago, Quercus, Urticaceae, Poaceae, Chenopodiaceae,Artemisia andAlternaria. The main sources of airborne particles wereAlternaria (27.7%), Cupressaceae (13.5%),Olea (9.36%), Chenopodiaceae (8.31%) and Urticaceae (5.8%). Annual variations in pollen abundance and length of the flowering seasons are given for individual species and are related to environmental factors. Results indicate a main pollen season from March to June and a second minor season in September to October. The relatively high concentrations of Genisteae and the appearance of anArtemisia winter season were noted.     

Monitoring of airborne pollen and pollen calendar of Cosenza,Southern Italy

Summary From May 1986 to May 1989 surveys of airborne biological particles have been performed in the atmosphere of Cosenza, Italy with the aim of monitoring the presence of airborne pollen. The survey station is situated at Arcavacata of Rende, a hilly area 474 meters above sea level, 7 km north-west of the main town. The sampler (VPPS 2000) is located about 20 meters above ground level. The monitoring, performed in accordance with the criteria suggested by the Italian Association of Aerobiology (A.I.A.), enabled the identification of 26 different pollen types. The pollination graphics show: 1) a late winter period in which pollen from trees appears; 2) a spring period with a prevalence of Gramineae, Fagaceae, Oleaceae andParietaria pollen; 3) a late spring-summer period during which Fagaceae,Pinus and Compositae pollen grains are present; 4) a late summer-autumn and winter period characterized by a drastic reduction of airborne pollen. A study of the calendar reveals, furthermore, that: 1) Gramineae pollen is, amongst those of allergological importance, the most representative; 2)Parietaria is not perennial and is present in modest concentrations; 3)Olea reaches a high peak in June, but not as high as in other southern regions; 3) pollen from arboreal plants is prevalent compared to that of herbaceous plants.     

Development of a semi-automatic system for pollen recognition

A semi-automatic system for pollen recognitionis studied for the european project ASTHMA. The goal of such a system is to provideaccurate pollen concentration measurements. This information can be used as well by thepalynologists, the clinicians or a forecastsystem to predict pollen dispersion. At first,our emphasis has been put on Cupressaceae, Olea, Poaceae and Urticaceae pollen types. The system is composed of two modules: pollengrain extraction and pollen grain recognition. In the first module, the pollen grains areobserved in light microscopy and are extractedautomatically from a pollen slide coloured withfuchsin and digitized in 3D. In the secondmodule, the pollen grain is analyzed forrecognition. To accomplish the recognition, itis necessary to work on 3D images and to usedetailed palynological knowledge. Thisknowledge describes the pollen types accordingto their main visible characteristerics and tothose which are important for recognition. Somepollen structures are identified like the porewith annulus in Poaceae, the reticulum in Oleaand similar pollen types or the cytoplasm inCupressaceae. The preliminary results show therecognition of some pollen types, likeUrticaceae or Poaceae or some groups of pollentypes, like reticulate group.     

Comparison between categorical pollen data obtained by Hirst and Cour sampling methods

Two methods of aerobiological collection, the Burkard(Hirst-based) and the Cour, were compared using datafrom pollen collected at Bellaterra (Barcelona, Spain)between 1994 and 1996. Results for three pollen taxaof allergenic relevance (Urticaceae, Poaceae andOlea) are presented. This study confirmed thedifficulty of finding a reliable conversion formulabetween these sampling methods, as has been found byseveral other authors.An alternative statistical analysis was carried outusing categorical data, the pollen concentration databeing first converted into an ordinal scale with fivelevels based on local records. Our analysis shows thatboth methods provide essentially the sameinformation.     

May the definition of pollen season influence aerobiological results?

This paper reviews the terms and major criteria used to define and limit the pollen season. Pollen data from Cordoba (Spain), Ourense (Spain) and Bologna (Italy) were used to ascertain the extent to which aerobiological results and pollen curves are modified by the criteria selected. Results were analysed using Spearmanȁ9s correlation test. Phenological observations were also used to determine synchronization between pollen curves and plant phenology. The criteria for limiting the shortest and longest pollen season periods, as well as the earliest and latest start and end dates, varied according to the city and the taxon under study; in many cases, results for a given taxon also depended on the year. The smallest differences were obtained for Platanus and the greatest for Poaceae.     

Pollen Ole e 1 content variations in olive cultivars of different Portugal regions

Olive is recognized as a crop with great impact in agricultural, socioeconomic, environmental and public health sectors. The last is becoming more important during recent years as consequence of the increase of the pollen allergy in south Europe prompted by the widespread Olea pollen allergic reactions. The aim of the study was to quantify, for the first time, the variations of the Ole e 1 allergen amount in Olea pollen grains from four cultivars in three regions of Portugal. How weather parameters can affect the allergen production was also assessed. The study was conducted in three olive producer areas of Portugal from 2010 to 2013, Santarém (Central), Elvas (Southeast) and Mirandela (Trás-os-Montes region, Northeast). Mature pollen of four different cultivars (Cobrançosa, Arbequina, Picual and Verdeal) was collected during the olive flowering season. Ole e 1 was quantified using specific 2-site antibody ELISA. Pollen of the olive groves at the boundary Olea bioclimatic distribution in the Mirandela registered the higher allergen content for all varieties in each study year. Arbequina was the variety that showed the lower Ole e 1 allergen concentration, whereas the higher content was registered for Cobrançosa. The main meteorological parameters that influenced the allergen Ole e 1 concentration in the pollen grains were the rainfall and temperatures related variables. The knowledge of the allergenicity in different olive cultivars is an important tool in the selection of the most adequate for planting as ornamental crop and to adjust the pollen extracts used for diagnosis or even immunotherapy.

     

Risk of pollen allergy in Nerja (southern Spain): a pollen calendar

An aeropalynological study was carried out in the atmosphere of the city of Nerja (southern Spain) during a period of 4 years (2000–2003), using a Hirst type volumetric pollen trap. An annual pollen index of 59,750 grains, on average, was obtained with 80–85% of the total pollen recorded from February to May, with Pinus, Olea, Urticaceae, Cupressaceae, Quercus and Poaceae being the principal pollen producers in abundance order. A total of 29 pollen types that reached a 10-day mean equal to or greater than 1 grain of pollen per m³ of air is reflected in a pollen calendar. The results were compared with those obtained for nearby localities and a correlation analysis was made between the daily fluctuations of the main pollen types and total pollen, and meteorological parameters (temperature, rainfall and hours of sun). The daily, monthly and annual values reached by the most important pollen types from an allergenic point of view (Olea, Urticaceae and Poaceae) confirms Nerja as a high-risk locality for the residents and the numerous tourists who visit the area.     

Phenological records as a complement to aerobiological data

Phenological studies in combination with aerobiological studies enable one to observe the relationship between the release of pollen and its presence in the atmosphere. To obtain a suitable comparison between the daily variation of airborne pollen concentrations and flowering, it is necessary for the level of accuracy of both sets of data to be as similar as possible. To analyse the correlation between locally observed flowering data and pollen counts in pollen traps in order to set pollen information forecasts, pollen was sampled using a Burkard volumetric pollen trap working continuously from May 1993. For the phenological study we selected the main pollen sources of the six pollen types most abundant in our area: Cupressaceae, Platanus, Quercus, Plantago, Olea, and Poaceae with a total of 35 species. We selected seven sites to register flowering or pollination, two with semi-natural vegetation, the rest being urban sites. The sites were visited weekly from March to June in 2007, and from January to June in 2008 and 2009. Pollen shedding was checked at each visit, and recorded as the percentage of flowers or microsporangia in that state. There was an association between flowering phenology and airborne pollen records for some of the pollen types (Platanus, Quercus, Olea and Plantago). Nevertheless, for the other types (Cupressaceae and Poaceae) the flowering and airborne pollen peaks did not coincide, with up to 1 week difference in phase. Some arguments are put forward in explanation of this phenomenon. Phenological studies have shown that airborne pollen results from both local and distant sources, although the pollen peaks usually appear when local sources are shedding the greatest amounts of pollen. Resuspension phenomena are probably more important than long-distance transport in explaining the presence of airborne pollen outside the flowering period. This information could be used to improve pollen forecasts.     

A comparative study on the effects of altitude on daily and hourly airborne pollen counts

The concentration of pollen grains in the air was studied using two aerobiological volumetric Hirst-type spore traps, one at ground level and the other at a height of 16 m on a terrace. The study was carried out between 2009 and 2011, from March to June in Badajoz (SW Spain). Intradiurnal and daily pollen counts were compared with both, different meteorological parameters and the distribution of local pollen sources. Forty-six pollen types were identified and 89 % of the total grains corresponded to Quercus, Poaceae, Olea, Pinaceae and Plantago pollen types, in descending order. The mean height ratio of the daily pollen count was 1.02. Significant correlations were observed when comparing daily pollen counts for predominant pollen types at both levels. The comparisons have shown significant differences in the daily pollen count between the two samplers in the case of Olea and Pinaceae, but not for Quercus, Poaceae and Plantago. Similar results were obtained using the intradiurnal airborne pollen database. No significant correlation has been found between pollen count and the different meteorological parameters, showing no dependence on height. These differences of Olea and Pinaceae may be explained in part by the uneven distribution of the pollen sources and the disturbance by nearby buildings. The temporal variation patterns between the two sites were similar; however, taking into account the average of the data, the higher values were obtained first at the ground level and later at 16 m.     

The effect of air temperature on the starting dates of theUlmus, Platanus andOlea pollen seasons in the SE Iberian Peninsula

A study is made of the effect of air temperature on the start of the pollen seasons of three tree species—Ulmus, Platanus andOlea—in the southeastern Iberian Peninsula. These initial results are based on an aerobiological analysis performed over a 4-year period in the city of Granada, Spain. Sampling was carried out with a Burkard spore trap. The main aim of the present study was to use regression analysis to identify the preseasonal date when these species start to accumulate heat in their floral buds, enabling models to be created that indicate the onset of the pollen season for these taxa. ForUlmus there was no significant correlation between the onset of pollination and the mean temperature during the preceding period, whereasPlatanus presented a significant correlation with mean temperature during the month of January, andOlea with mean temperature during the second fortnight in February and the month of March. ForUlmus, the start of the pollen season ranged between 30 January and 8 February; forPlatanus, between 13 and 17 March; and forOlea, between 20 April and 13 May. The accumulated temperature needed to induce the onset of flowering ranged between 121 and 256°C forUlmus, with values of 428–607°C and 656–881°C forPlatanus andOlea, respectively.     

Aeropalynological study of <Emphasis Type="Italic">Vitis vinifera</Emphasis> in the Braga region (1999–2003)

This study shows the results of Vitis vinifera pollen season in the atmosphere of the Braga region (Portugal) for the last 5 years (1999–2003). The fluctuations in the airborne pollen concentration, the synchronic rhythms in the annual pollen trends and their relationship to the main meteorological parameters were investigated. The vineyard pollen season extends from late May to early July, presenting always a bimodal pattern. During the studied period several pollen types such as Poaceae, Castanea, Olea, Urticaceae, Quercus, Plantago, Rumex, Asteraceae, Pinaceae, Ericaceae and Eucalyptus were also observed. Airborne pollen concentration is highly influenced by mean temperature, rain, number of days with rain and wind direction.     

The relationship between airborne pollen distribution and the frequency of specific pollen sensitization at two climatically different locations in Switzerland

Pollen data reported from the two monitoring stations of Locarno-Monti, on the southern slopes of the Alps, and Zurich on the northern slopes of the Alps, for the years 1989–1993 were compared with meteorological data from the corresponding locations and with the prevalence of pollinosis and frequency of specific pollen sensitization in patients with pollinosis. It was so discovered that the recorded quantity of allergenic pollen types (Alnus, Corylus, Betula, Fraxinus, Poaceae, Castaneae,Olea andArtemisia) south of the Alps is higher by a factor of 2.9 than that north of the Alps. These differences are due to the distinctly milder climate in the canton of Ticino (south of the Alps) showing higher annual mean temperatures, more sunshine duration and less precipitation days with higher amounts of precipitation. The allergological data show additionally that the summer pollinosis, caused byCastanea andOlea, is probably responsible for the differing prevalence of pollinosis at the two sites. Finally, we can summarize that in Switzerland pollen from Poaceae, Betulaceae and Oleacea are the most important for pollinosis.     

The reliability of geostatistic interpolation in olive field floral phenology

Floral phenology, as most of natural phenomena, shows, as an inherent feature, a high degree of spatial continuity. Geostatistics are a family of statistics that describe correlations through space/time and they can be used for both quantifying spatial correlation and interpolating no monitored sampling points. The combined use of Geographical Information Systems (GIS) and geostatistics can be an essential tool for spatial analysis in phenological and aerobiological studies. In the present work, Kriging interpolation by using linear geostatistic analysis has allow us to estimate phenological data of a wide olive crop area of the province of Cordoba (Andalusia, Southern Spain), on the basis of a limited number of␣phenology sampling points. The main a priori hypothesis was that 7 traditionally observed sampling points (with 10 olive trees in each site) uniformly distributed through the main olive crop areas could be enough for interpolating phenological information of the whole Cordoba olive area. Geostatistical results reject this hypothesis. The optimum/minimum number and location of sampling points was determined in 13 sites (including the original 7 sites and 6 new sites). The obtained phenological maps will improve␣olive pollen aerobiological information and forecasting in the area. The application of such new combined space analysis tools on floral phenology allows optimising human and economic resources on field phenology campaigns. Moreover, an appropriate use of GIS and geostatistic software to create phenological maps will be an essential complement in pollen aerobiological studies, given the increased interest in obtaining automatic aerobiological forecasting maps.