an exPloRatoRy analysis of seasonal and  
intRaseasonal vaRiations of the main aiRboRne Pollen  
tyPes in sunchales city, aRgentina  
análisis exPloRatoRio de las vaRiaciones estacionales e  
intRaestacionales de los PRinciPales tiPos Polínicos en la atmósfeRa  
de la ciudad de sunchales, aRgentina  
1,2  
y Ana G. Ulke  
Claudio F. Pérez * , Mauro Covi , María I. Gassmann  
Resumen  
Introducción y objetivos: El estudio de la variabilidad estacional e intraestacional de  
la concentración de polen en el aire es de suma importancia para comprender las  
relaciones con la vegetación emisora y los parámetros atmosféricos que modulan  
el transporte de polen. Esta investigación tiene como objetivo estudiar estas  
variabilidades en Sunchales, una ciudad ubicada en el centro-este de Argentina.  
M&M: El monitoreo atmosférico se realizó con una trampa Burkard durante dos  
temporadas en 2012 y 2013 en las afueras de la ciudad.  
Resultados & Conclusiones: Los períodos de polinización de los tipos de polen  
estudiados muestran un retraso en 2013 en comparación con el año anterior,  
presuntamente relacionado con una mayor cantidad de unidades de calor  
acumuladas en 2012. Sin embargo, la integral polínica para el período 2013 fue  
1
. Departamento de Ciencias  
de la Atmósfera y los Océanos,  
Intendente Güiraldes 2160,  
do  
2
piso, Pabellón II, Ciudad  
Universitaria, C1428 EHA Buenos  
Aires, Argentina.  
2
. Consejo Nacional de  
Investigaciones Científicas y  
Técnicas.  
*
perez@at.fcen.uba.ar  
1,4 veces mayor que 2012, hecho que no se explica por la precipitación acumulada  
sino por la hora del día en que ocurren los hidrometeoros. Las concentraciones de  
polen categorizadas en rangos muestran que los valores mayores coinciden con  
la ubicación urbana de las fuentes arbóreas mientras que las herbáceas muestran  
una asociación con un origen rural. En cuanto a la variabilidad intraestacional,  
la mayor proporción de la varianza del polen en el aire se acumula en la escala  
sinóptica (80 - 60%) con períodos entre 3 y 10 días. Durante 2012 predominaron  
las ondas largas (> 5,5 días) mientras que en 2013 predominaron las ondas medias  
Citar este artículo  
PÉREZ, C. F., M. COVI, M. I.  
GASSMANN & A. G. ULKE. 2021.  
An exploratory analysis of seasonal  
and intraseasonal variations of  
the main airborne pollen types in  
Sunchales city, Argentina. Bol. Soc.  
Argent. Bot. 56: 269-287.  
(3,9 - 5,5 días).  
PalabRas clave  
Análisis de Fourier, concentraciones de polen en el aire, influencia meteorológica,  
Santa Fe, trampa Burkard.  
summaRy  
Background and aims: The study of the seasonal and intra-seasonal variability  
of the airborne pollen concentration is of paramount importance to understand  
the relationships with the emitting vegetation and the atmospheric parameters  
that modulate pollen transport. This research aims to study these variabilities in  
Sunchales, a city located in the center-east of Argentina.  
M&M:Atmospheric monitoring was carried out with a Burkard trap during two seasons  
in 2012 and 2013 on the outskirts of the city.  
Results & Conclusions: The pollination periods of the studied pollen types show  
a delay in 2013 compared to the previous year, presumably related to a greater  
amount of cumulative heat units in 2012. However, the integral pollen for the period  
2013 was 1.4 times higher than 2012, a fact that is not explained by accumulated  
precipitation but by the time of day when the hydrometeors occur. Binned pollen  
concentrations show that the highest concentrations coincide with the urban  
location of the tree sources while the herbaceous ones show an association with  
a rural origin. Regarding the intra-seasonal variability, the highest proportion of the  
airborne pollen variance accumulates on the synoptic-scale (80 - 60%) with periods  
between 3 and 10 days. During 2012 long waves predominated (> 5.5 days) while  
in 2013 medium waves prevailed (3.9 - 5.5 days).  
Recibido: 23 Ene 2021  
Aceptado: 22 Jun 2021  
Key woRds  
Publicado en línea: 2 Sep 2021  
Publicado impreso: 30 Set 2021  
Editor: Gonzalo Márquez  
Airborne pollen concentrations, Burkard trap, Fourier analysis, meteorological  
influence, Santa Fe province.  
ISSN versión impresa 0373-580X  
ISSN versión on-line 1851-2372  
269  
Bol. Soc. Argent. Bot. 56 (3) 2021  
intRoduction  
mateRials and methods  
Forecasting airborne pollen concentrations Study area  
is undeniable of high importance to biological,  
Sunchalesisanagricultureandindustrialcitylocated  
environmental, and ultimately medical practice in the core area of Argentine agricultural production.  
(
Aznarte et al., 2007). The presence and amount According to the records of the National Institute  
of airborne pollen depend on a wide range of Statistics and Censuses, its population is 21,304  
of factors that can be grouped into physical, inhabitants. From the phytogeographic standpoint, the  
concerning meteorology (wind, rain, air city of Sunchales is located in the Espinal province  
humidity, and temperature) and biological, (Lewis & Collantes, 1973; Cabrera, 1976; Morello et  
which depends on plant distribution, stand al. 2012), where the predominant natural physiognomy  
maturity, phenological, physiological, and should resemble a xerophytic leguminous forest with  
phytosanitary conditions among others. As there a stratum of grasses, interspersed with large Savanna  
is no standardized modeling approach, many or Park areas. According to Oyarzábal et al. (2018),  
authors tried to generate models of different the location corresponds to the Algarrobal unit:  
nature (eg. Arizmendi et al., 1993; Hjelmroos, “Sclerophyll forest with Prosopis nigra and Prosopis  
1
&
992; Kawashima & Takahashi, 1999; Levetin alba”. However, agricultural-livestock activity  
Van de Water, 2003; Voukantsis et al., 2013; produced a significant modification of the landscape,  
Fernández-Rodríguez et al., 2016; Damialis et where natural vegetation has been relegated to small  
al., 2017 and many others), whose application patches in abandoned fields or along rural roads. As  
has provided variable results. Pollen forecasting a result, the present physiognomy corresponds to  
is a hard problem to be solved not only because a Savanna where the dominant woody species are:  
of the chaotic nature of the airborne pollen Geoffroea decorticans (Gill. ex Hook. &Arn.) Burkart,  
concentration intended as a time series of Vachellia caven (Molina) Seigler & Ebinger, and  
infinite length (Bianchi et al., 1992), nor by the Parkinsonia aculeata L., accompanied by different  
high quantity of variables involved, but to the herbs and ruderal species. The most widespread  
complexity of space and time scales in which these economic activity is agriculture, mostly dedicated to  
variables operate on the system. Moreover, these dairy, where large plots are destined for feeding cattle  
variables may have synergistic or antagonistic with extensive cultivation of Medicago sativa L. and  
effects depending on the timing of their temporal grasses. In the urban area, the floristic composition  
variability. Topography, as well as natural and includes numerous exotic tree species grown as  
anthropogenic barriers, add new difficulties to be ornamentals along the streets, in public parks and in  
solved. This has meant that the common answer private gardens. The most abundant species are Morus  
to the challenge of forecasting airborne pollen sp., Broussonetia papyrifera (L.) Vent., Maclura  
concentrations is to build pollen calendars, pomífera (Raf.) C.K. Schneid., Bauhinia variegata  
however, more robust solutions require knowing L., Platanus × hispanica Mill. ex Münchh., Fraxinus  
specific site-dependent interactions between excelsior L., Cupressus sempervirens L., and C.  
biological and physical variables at different macrocarpa Hartw. ex Gord. Some other species like  
time and space scales. A two-year survey of Populus deltoides W. Bartram ex Marshall, P. alba L.,  
the atmospheric pollen content in the city of and P. nigra L. are planted as windbreaks in the city  
Sunchales (Santa Fe, Argentina), allowed a first outskirts.  
characterization of the aeroflora, determining  
According to the updated Köppen-Geiger  
the incidence and prevalence of the pollen classification (Kottek et al., 2006), the climate is Cfa  
content, and to estimate the allergenicity of the type: warm temperate with average annual temperature  
pollen types present in the local air (Pérez et al., and precipitation of 18.5 °C and 928 mm respectively.  
2
020a). In this paper, we address the preliminary July is the driest and coldest month (24 mm, 12 °C),  
analysis of the relationship between airborne while the highest rainfall is recorded in March (147  
pollen variability of the main pollen types, mm), and the maximum temperature in January (25.1  
with meteorological parameters at seasonal and °C) (Argentine National Weather Service Climatology  
intraseasonal timescales for the place.  
for the period 1999-2000).  
270  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
Airborne pollen monitoring  
specialized literature (Heusser, 1971; Markgraf  
Atmospheric pollen monitoring was carried & D’Antoni, 1978; Pire et al., 1998, 2001).  
out in two periods (01/08/2012 - 27/11/2012; Pollen data are expressed as a daily concentration  
-3  
0
9/08/2013 - 05/12/2013) from the Southern (pollen grains per cubic meter of air, gr m ).  
Hemisphere late winter to late spring when the Data for the period 11/11/13 to 14/11/13 were  
highest palynological richness is observed in lost due to pollen trap malfunctions. To maintain  
most of the localities studied in Argentina (Pérez the continuity of the series, the missing data  
et al., 2020b and references therein). The survey were linearly interpolated. Hourly and daily  
was carried out with a Burkard trap located meteorological data (hourly, daily maximum and  
approximately 3 km SW of the geographical minimum temperatures, hourly wind speed and  
center of the city, at the National Weather Service direction, hourly pressure, present weather, and  
station of the Sunchales airfield (30° 57’ 24.5” daily precipitation) measured at Sunchales airfield  
S, 61° 31’ 59.2” W, 93, Fig. 1). The trap was station were provided by the National Weather  
operated at a constant suction volume of air Service for 2012 and 2013.  
3
-1  
(
0.6 m h ), with the inlet at 1.3 m above the  
The pollen integral in the 01/08/2012 -  
-3  
ground. The trap works with the volumetric - 27/11/2012 period reached 1830.3 gr m (13,178  
isokinetic technique designed by Hirst (1952), grains), while on 09/08/2013 - 05/12/2013 it was  
which is widely used in Europe and Asia for 1.4 times higher, with a total of 2564.3 gr m  
-
3
aerobiological sampling and is described in detail (18,463 grains) (Pérez et al., 2020a). Up to 94  
in numerous published papers (eg. Bianchi, 1992, pollen types were recognized in both records,  
1
994; Latorre, 1999a; Pérez, 2000; Latorre & nevertheless, 74% (2012) and 72% (2013) of  
Caccavari, 2010). The preparation of the sticky these pollen sums are represented by the most  
surface and the assembly of the slides was carried abundant Urticaceae, Moraceae, Poaceae, and  
out by standard techniques (Käpylä & Penttinen, Cupressaceae pollen types which also show the  
1
981). Pollen counting was performed with an longest and continuous pollen records. These  
optical microscope with a final magnification of pollen types are allergenic species (Pérez et al.,  
00x, analyzing the complete slide obtained for 2020a), therefore, they were selected for further  
4
each day. Pollen types were recognized based on analysis in this paper (Appendix).  
Fig. 1. Location of the sampling site and rotated coordinate system used for wind component decomposition  
(see text).  
271  
Bol. Soc. Argent. Bot. 56 (3) 2021  
bacKgRound  
al. (1992) and Seeley et al. (1996) state that after a  
dormancy period, the accumulation of heat above a  
Pollen concentrations are reported as discrete temperature threshold is required to start the pollen  
data series at regular time intervals of x seconds, shedding, therefore, heat units were calculated  
minutes or hours. Therefore, the summarization with the single triangulation method (Zalom et al.,  
of its properties using time-series methods are 1983) to analyze PPP-temperature relationships  
appropriate. In this context, the variability of an for this timescale. The required lower threshold  
observed pollen data set (S) could be viewed as temperature was set at 5.5°C according to the  
contributions from natural processes occurring at recommendations of several authors for Urticaceae  
different timescales, or characteristic frequencies:  
(Urtica dioica L.), Moraceae (Morus rubra L.,  
M. microphylla L., Maclura pomifera (Raf.) C.K.  
Schneid.), and Poaceae (Holcus lanatus L., Festuca  
rubra L., Poa annua L.) (Bassett et al., 1977; Liem  
S = S + S + S + S + ε  
t
a
s
is  
With S the change due to long-term trend, S , & Groot, 1980; Emberlin et al., 1994; Thompson  
t
a
S , S , the interannual, seasonal, and intraseasonal et al., 2000; García - Mozo et al., 2009; Zhang et  
s
is  
variabilities and an error term. This approach al., 2015).  
allows us to progressively remove the variability Intraseasonal variability (S ) was studied with  
is  
of different timescales to analyze its relationship Fourier Analysis (Wilks, 2011) from the residuals  
with presumed biological or meteorological driving obtained after removing the binomial filter from the  
processes. The length of our record did not allow us original series of observed data (high pass filtering).  
to analyze the first two terms, which require longer The new series contains k sub-seasonal timescales  
data sets (several years).  
intended as cycles throughout N observations  
There are different techniques to study S , being (frequency). These cycles could be represented  
s
the most common to determine the main pollen- as having arisen from k series of sine and cosine  
season or principal pollination period (PPP) with functions that being expressed in complex notation,  
the onset and peak dates (García-Mozo et al.,  
2
009). Most of the methods that calculate PPP,  
require counting at least a whole year record since  
the key dates are defined as a percentage of pollen  
accumulated from the annual pollen sum (Pathirane,  
1
1
975; Lejoly-Gabriel, 1978; Nilsson & Persson, Where N is the total number of data in the series,  
981; Frenguelli et al., 1991) while others detect t is the sampling interval, H is the complex Fourier  
k
these dates upon reaching some pre-established coefficient H = A + i B with A the real and B the  
k
k
k
k
k
i[2πk/N]t  
concentration thresholds (Mullenders et al., 1972; imaginary part of H , and e  
= cos(2πt/N) + i  
k
Mäkinen, 1977; Driessen et al., 1989, 1990; sin(2πt/N) with i = √-1 (Wilks, 2011).  
Norris-Hill, 1998). The procedure employed in this  
The Fourier transform X(k) which gives the  
paper resembles that of Norris-Hill (1998) which frequency spectrum could be obtained as:  
overcomes the annual pollen sum requirement  
being more suitable to our data. A low pass filtering  
procedure was applied to reduce the high-frequency  
variability, afterward selecting the onset of the  
pollination period, as the date from which filtered  
As X(k) is computationally time-consuming, the  
pollen concentration increases at least 5% for 5 most used tool to calculate the frequency spectrum  
consecutive days. Low pass filtering was performed is the Fast Fourier Transform (FFT). The data for  
with a 17 weights binomial filter which, instead of this study were pre-treated as follows: The series  
a moving average procedure, preserves the phase for both years were trimmed to 96 data points (7  
of the oscillations and enhances the information of days were eliminated in 2012 and 8 days in 2013)  
periods longer than 10.7 days.  
and tapered with 10% data generated with a cosine  
Temperature is considered the main driver of the function at both ends of the series. This technique  
pollination period by many authors. Frenguelli et reduces distortions introduced by errors (aliasing)  
272  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
to the high frequencies. Pollen concentration series is obtained from applying empirical techniques  
were tapered only when the pollen season was to detect the onset, peak, and end dates of the  
truncated. For Fourier analysis the wind vector pollination season. The binomial filtering showed  
was decomposed into its NE-SW and SE-NW that 2012 and 2013 seasonal patterns are quite  
components using a counterclockwise π/4 rotated similar with the only exception of Cupressaceae.  
coordinate system (Fig. 1). NE and SE directions Seasonal patterns are multimodal as pollen types  
were considered positive while SW and NW represent several genera and species which may  
negative. The idea of this coordinate transformation show different flowering times (Fig. 2). Along with  
arose from considering the shape of the wind rose the increase in concentration, there is a concomitant  
that presented two axes of maximum variability delay of the 2013 pollination season, which seems  
in the NW - SE and NE - SW directions (see Fig. to be greater in tree pollen types (Pérez et al. 2020a).  
6
). In addition, the city is located to the NW of Moraceae and Urticaceae exhibit 3 and 4-day delays  
the position of the pollen trap (Fig. 1). Thus, the respectively, while Poaceae scarcely registers a  
transformation used maximizes the variability of 1-day delay. The onset of the Cupressaceae season  
the wind rose and the urban-rural contrast of the could not be determined since pollen shedding  
pollen sources.  
started well before the beginning of the record.  
Many kinds of research relate the seasonal  
The calculated frequency spectra were smoothed  
with a Parzen filter of 11 weights to prevent the pattern with different meteorological variables,  
misidentification of peak frequencies due to noise. mainly temperature and precipitation (eg. Galán  
Spectra were converted to periodograms where et al., 1995; Smith & Emberlin, 2006; Brighetti et  
-1  
period [days] = frequency .  
al., 2014). Blooming species growing in the same  
The choice of a filter with a cut-off period of 10.7 environment have a marked tendency to present the  
days makes it possible to preserve the synoptic- same onset advance or delay, being the temperature  
scale variability in the residuals. Although there the determinant factor (Marletto et al., 1992). Mean  
is no agreement on the time span for this scale, daily temperature (Fig. 3), statistically have the  
ranging from 0.5 days to 1 month (Eskridge et al., same rate of increase (α= 0.05) with 2012 slope =  
-1  
997; Gulev et al., 2002; Hogrefe et al., 2003), 0.083 ±0.008 Julian day and 2013 slope = 0.080  
-1  
1
we follow the criteria of Solman & Menéndez ±0.008 Julian day . Nevertheless, cumulative  
2002) who consider the synoptic-scale variability heat units show greater differences between both  
(
to be up to 10 days for the Southern Hemisphere. sampling periods (Fig. 4), which seem to explain  
Particularly, in the Fourier spectra, the synoptic- the registered delay.  
scale was analysed considering 3 equal frequency  
The year 2012 was slightly warmer than in  
bandwidths whose ranges expressed as periods are: 2013, shown by a higher minimum temperature  
short waves (3.1 - 3.9 days), medium waves (3.9 - (Table 1), which agrees with the differences in  
5
.5 days), and long waves (5.5 - 8.7 days).  
pollen productivity registered between both years.  
According to Cadman et al. (1994), temperature as  
a controlling factor of the intensity of the pollination  
season is higher during the summer, when trees  
accumulate the major amount of resources available  
for reproduction in the next spring. By the end of  
Results and discussion  
Seasonal characteristics of the pollination period  
Comtois (1998, 2000) concludes that the seasonal the growing season, these resources are consumed  
pattern of any pollen type should be a Normal by the pollen grains that start to form in the anthers  
distribution function as it is the ideal statistical (Emberlin et al., 1990). Therefore, we suggest that  
model following the aerobiological pathway of the higher temperature registered in 2012 drives  
release, dispersal, and deposition phases described higher pollen concentrations in 2013. Besides,  
by Edmonds (1979). Nevertheless, this can only be precipitation has different effects on the airborne  
achieved when averaging a long time series of data. pollen record according to the scale of analysis  
Short records like ours usually show quite large considered.  
deviations from a Normal distribution function, so  
It has been shown that the amount of  
that the information referred to the seasonal scale inflorescences is related not only to temperature  
273  
Bol. Soc. Argent. Bot. 56 (3) 2021  
Fig. 2. Airborne pollen series of selected pollen types for the periods 2012 and 2013. Lines show the  
seasonal trends calculated with a 17-weights binomial filter. Arrows indicate the starting dates for the  
principal pollen seasons.  
Fig. 3. Daily mean temperatures and linear trends from August 1 to December 5.  
274  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
Fig. 4. Accumulated heat units from the winter solstice (Southern Hemisphere) to the end of the sampling  
period (December 5) calculated with the single triangulation method (Zalom et al., 1983) and 5.5°C lower  
threshold temperature. Inset shows the starting dates for the principal pollen seasons (blue arrows for  
Moraceae, green arrows for Urticaceae and yellow arrows for Poaceae).  
but to the quantity of rain fallen in the preceding result, airborne pollen concentration tends to  
flowering season (Stach et al., 2008). In this sense, decrease after rainstorms (Latorre, 1999b; Peternel  
the high pollen integral recorded in 2013 could et al., 2004; Lo & Levetin, 2007; Jato et al.,  
also be due to the high annual precipitation in 2012 2002). Cumulative precipitation within 2012 and  
(Table 1). Nevertheless, although prevailing weather 2013 sampling periods are virtually equal which  
before a flowering season plays an important does not presuppose to be of marked influence to  
role, environmental factors alone cannot explain pollen concentrations (Table 1). However, mist  
fluctuations, and other biological factors such as and fog frequencies are markedly higher in 2012  
masting should also be considered (Janzen, 1976; that could contribute to the lower amount of pollen  
Kelly, 1994; Koenig & Knops, 2005). Some authors collected during the first sampling period (Table  
explain that this behavior responds to a resource 1). Moreover, the hourly distribution shows that  
allocation strategy due to the modular structure of in 2013 the maximum frequency of mist and fog  
trees (Isagi et al., 1997; Masaka et al., 2001; Ranta is within the time range in which pollen release  
et al., 2005; Miyazaki, 2013).  
occurs, but in the previous year, their distribution  
On the other hand, airborne pollen becomes (as in the case of rain and drizzle) is more even,  
condensation nuclei to the formation of cloud affecting daylight hours when pollen is mainly  
droplets (Huffman et al., 2013). Falling raindrops present in the air (Fig. 5). Although biological  
also produce the washout of suspended particles aerosols are only a fraction of the condensation  
which is largely recognised in the literature as nuclei present in the air, they are especially  
an efficient method of pollen removal from the important since they start condensation with low  
atmosphere (McDonald, 1962, 1964; Gatz & levels of moisture saturation (Bauer et al., 2003).  
Dingle, 1963; Scriven & Fisher, 1975). As a Besides, they also prevail in the lower atmosphere,  
275  
Bol. Soc. Argent. Bot. 56 (3) 2021  
while in 2013 the most frequent wind came from E,  
SW, S, and NE directions. The mean intensity was  
Table 1. Average temperatures and accumulated  
precipitation in 2012 and 2013 years. Percentage  
frequency of hydrometeors was calculated from August 1  
to December 5  
-1  
slightly higher in 2013 (4.3 m s ) compared to 2012  
-1  
3.8 m s ). Lower intensities were higher in 2012,  
(
especially from E and S directions. High intensities  
in 2012 were associated with NNE and E directions  
while in 2013 are evenly distributed.  
Year  
Average maximum  
temperature (°C)  
2012  
2013  
26.4  
26.4  
Despite the low wind frequencies, and regardless  
of the year, the highest Cupressaceae and Moraceae  
concentrations come from WNW - N directions,  
which points out the position of the city (see Figs.  
Average minimum  
temperature (°C)  
13.1  
19.8  
2794  
1
12.4  
19.4  
2337  
0.8  
Mean temperature (°C)  
Annual precipitation (mm)  
Fog frequency (%)  
1
and 7). Poaceae shows the opposite pattern with  
higher frequencies of peak concentration from  
directions between S and ENE (Fig. 8). Morus  
spp., Maclura pomifera (Raf.) C.K. Schneid.,  
Broussonetia papyrifera (L.) Vent. along several  
Cupressus species, are found in the parks and streets  
of the city while Poaceae sources are more abundant  
in the surrounding countryside (Pérez et al., 2020a).  
A second Cupressaceae maximum is seen towards  
W - SW due to a tiny Taxodium distichum (L.) Rich.  
tree growing a few meters from the trap. Urticaceae  
Mist frequency (%)  
10.6  
0.6  
7.4  
Rain frequency (%)  
Drizzle frequency (%)  
1
2.5  
1.1  
Cumulative precipitation  
during the sampling  
period (mm)  
808  
809  
therefore fog presumably removes pollen more does not show a clear pattern (Fig. 8). During 2012  
efficiently from the atmosphere than rainy events high pollen concentrations came from SW - W, and  
(
Pérez et al., 2009).  
N - ESE, while during 2013, they came from NW  
NNW, and ENE - SSE directions which show a  
greater impact of the change in wind direction than  
-
Airborne pollen concentration and wind  
The most notable characteristic of the wind in the case of tree species. Urtica and Parietaria  
rose is the low wind frequency between WNW - are the two most frequently cited genera of the  
NNE (Fig. 6), which is a regional climatic feature Urticaceae family in aerobiological literature and  
confirmed by other localities near the study site. both are present in the city of Sunchales (Pérez et  
The most frequent directions were E and S in 2012, al., 2020a). The differences found in both sampling  
Fig. 5. Daily frequency distributions of hydrometeors during 2012 and 2013 sampling periods.  
276  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
Fig. 6. Wind roses at Sunchales station for the 2012 and 2013 study periods.  
Fig. 7. Airborne pollen concentration of Cupressaceae (upper row) and Moraceae (lower row) by wind direction.  
277  
Bol. Soc. Argent. Bot. 56 (3) 2021  
Fig. 8. Airborne pollen concentration of Poaceae (upper row) and Urticaceae (lower row) by wind direction.  
seasons could be due to changes in the spatial Intra seasonal scale results  
distribution of these weeds. Results showed that  
Despite the year, the highest wind speed (SE-  
feasible tree pollen source inventory could be easily NW and NE-SW rotated components) percentage  
achieved from vegetation censuses of the city. Other variances accumulate in the high-pass filter but  
plants like weeds and grasses could be mapped by when the mean temperature and pressure are  
remote sensing, although annual growth habits considered, it is found in the low-pass filter (Tables  
and practices like regular lawn mowing constrain 2 and 3). This indicates that even analysing periods  
the effectiveness of this technique to model pollen less than one year, the most important temperature  
sources (Skjøth et al., 2010).  
and pressure changes respond to seasonal-scale  
Not only direction and speed but persistence forcing, while the wind depends on shorter-time  
as well should be included in these analyses as (synoptic) scale processes. The pollen variables  
recommended by other authors, particularly when do not present a recognizable pattern over time  
moderate to weak winds prevail throughout the year since they respond to both physical and biological  
(Damialis et al., 2005). Nevertheless, the pursuit sources of variability. The synoptic-scale variability  
of statistical relationships and interactions among includes 65 - 77 percentage variance of the high-  
speed, direction, and persistence should require pass filtered meteorological variables, while for  
longer study periods than those analyzed in this pollen these percentages are 72 - 81% (2012) and  
paper, especially aiming at forecast purposes.  
60 - 79% (2013) (Tables 2 and 3).  
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C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
Table 2. Percentage variance decomposition of the weather and pollen variables measured in 2012.  
Variance  
decomposition  
Range  
(d)  
Urticaceae Cupressaceae Poaceae Moraceae MP  
93 96 40 37  
MT  
WS1  
WS1  
3
1.3  
5.8  
2 2  
41 hPa 23 °C  
Total variance  
-3  
2
-3  
2
-3  
2
-3  
2
-1  
2
-1  
2
(gr m )  
(gr m )  
(gr m )  
(gr m )  
(m s ) (m s )  
Low-pass filtering  
9
6 – 10.5  
49.7  
63  
71.4  
49.4  
56  
44  
59  
41  
70  
30  
61  
18  
21  
38  
62  
68  
32  
47  
20  
33  
6.5  
93.5  
69  
(LPF) %  
High-pass  
filtering (HPF) %  
Synoptic waves  
1
0.5 - 2  
50.3  
80.1  
37  
75.5  
24.5  
40  
28.6  
72.4  
27.6  
21  
50.6  
81  
8
.7 – 3.1  
77  
(
% of HPF)  
Other waves  
% of HPF)  
< 3.1 and  
> 8.7  
19.9  
19  
23  
31  
(
Long synoptic  
waves  
Medium synoptic  
waves  
Short synoptic  
waves  
8
5
3
.7 – 5.5  
.5 – 3.9  
.9 – 3.1  
44  
38  
18  
52  
63.4  
20.4  
16.2  
49.3  
20.5  
30.2  
40  
46.5  
32.5  
31  
20  
17  
References: MP= Mean pressure, MT= Mean Temperature, WS1= Wind speed (SE-NW) and WS2= WS (NE-SW).  
The series of mean temperature, pressure and for the periods 6.9 and 7.4 days respectively  
wind components (Table 2) show a predominance (Figs. 11A and 12B). Medium waves explain the  
of long waves in 2012, with maximum density highest proportion of Poaceae variance (46.5%,  
for the periods 6.9, 7.4, 6.9 (SE-NW) and 6.4 Table 2) with a peak for 4.6 days (Fig. 12A), while  
(NE - SW) days respectively (Figs. 9A-B, 10A- Cupressaceae gathers 80% between medium and  
B). Long waves predominate in Moraceae (52%) long waves with respective maximum densities for  
and Urticaceae (44%) with maximum densities 4.6 and 7.4 day periods (Table 2 and Fig. 11A).  
Table 3. Percentage variance decomposition of the weather and pollen variables measured in 2013.  
Variance  
decomposition  
Range  
(d)  
Urticaceae Cupressaceae Poaceae Moraceae  
53 236 117 250  
MP  
MT  
WS1  
WS2  
1
2
7.5  
2 2  
47 hPa 44 °C  
Total variance  
-3  
2
-3  
2
-3  
2
-3  
2
-1  
2
-1  
2
(gr m )  
(gr m )  
(gr m )  
(gr m )  
(m s ) (m s )  
Low-pass filtering  
9
6 – 10.5  
55  
51  
72  
64  
62  
80  
20  
68  
32  
43  
42  
15  
11  
7
(
LPF) %  
High-pass filtering  
HPF) %  
Synoptic waves  
% of HPF)  
Other waves  
% of HPF)  
1
0.5 - 2  
45  
49  
28  
36  
59.9  
40.1  
28  
38  
89  
93  
(
8
.7 – 3.1  
78.6  
76.5  
23.5  
48.3  
35.1  
16.6  
61.9  
38.1  
44.1  
40.5  
15.4  
65.7  
34.3  
42.1  
42.8  
15.1  
66.3  
33.7  
33.7  
46.3  
20  
64.7  
35.3  
46.8  
35.5  
17.7  
(
< 3.1 and  
> 8.7  
21.4  
(
Long synoptic  
waves  
Medium synoptic  
waves  
Short synoptic  
waves  
8
5
3
.7 – 5.5  
.5 – 3.9  
.9 – 3.1  
34.5  
33.1  
32.4  
41  
31  
References: MP= Mean pressure, MT= Mean Temperature, WS1= Wind speed (SE-NW) and WS2= WS (NE-SW).  
279  
Bol. Soc. Argent. Bot. 56 (3) 2021  
Fig. 9. Smoothed Fourier spectra for daily mean temperature (A, C) and daily mean pressure (B, D) for the  
periods 2012 and 2013. Short waves: 3.1 - 3.9 days, Medium waves: 3.9 - 5.5 days, Long waves: 5.5 - 8.7 days.  
Fig. 10. Smoothed Fourier spectra for daily wind speed for the periods 2012 and 2013. Left column (A, C)  
represent the NW - SE component and right column (B, D) the NE - SW wind component. Short waves: 3.1  
-
3.9 days, Medium waves: 3.9 - 5.5 days, Long waves: 5.5 - 8.7 days.  
280  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
Fig. 11. Smoothed Fourier spectra for daily airborne pollen concentration of arboreal species for the periods  
2012 and 2013: Cupressaceae (A, C) and Moraceae (B, D). Short waves: 3.1 - 3.9 days, Medium waves:  
3.9 - 5.5 days, Long waves: 5.5 - 8.7 days.  
Fig. 12. Smoothed Fourier spectra for daily airborne pollen concentration of herbaceous species for the  
periods 2012 and 2013: Poaceae (A, C) and Urticaceae (B, D). Short waves: 3.1 - 3.9 days, Medium waves:  
3.9 - 5.5 days, Long waves: 5.5 - 8.7 days.  
281  
Bol. Soc. Argent. Bot. 56 (3) 2021  
In 2013 the greatest meteorological variability pollen concentration favored by clear skies, high  
was concentrated in the long bandwidths for NE- irradiance and light breezes, which occur with  
SW wind, mean pressure and mean temperature anticyclonic conditions.  
(
Table 3). The most frequent periods correspond  
to 6.9 days for NE-SW wind component (Fig. ones, the increase/decrease in temperature triggers/  
0D) and 9.6 days for pressure and temperature inhibits floral ripening and opening that occur in  
Fig. 9C-D). Medium waves are also important more or less regular pulses. This is hardly seen in  
Excluding short-wave variations like circadian  
1
(
in temperature, pressure and the SE-NW wind phenological studies as they usually rely on weekly  
component (Table 3). The most frequent periods are observations. Nevertheless, some authors discuss  
4
.8, 5.1 and 4.6 days (Figs. 9C-D, 10C). Regarding the effect of weather in floral phenology (Galán et  
pollen, Cupressaceae presents 48% of its variability al., 1986; Latorre, 1997).  
in long waves with peaks in periods of 6.4 and Our results show that, precisely located sources  
.7 days (Table 3 and Fig. 11C) while Poaceae such as Moraceae (urban) or Cupressaceae  
8
accumulates 84.6% in medium and long waves, (a tree located a few meters SW of the trap)  
with peaks for 4.2 and 6 days respectively (Fig. show variabilities in the same bandwidth as the  
1
2C). Moraceae presents the greatest contribution NE-SW and SE-NW wind speed components  
in medium waves (41%) and periods of 3.8 and respectively. Velasco & Fritsch (1987) show  
.3 days (Fig. 11D). In 2013 Urticaceae showed that in the midsection of Argentina mesoscale  
5
even variability in all bandwidths of the synoptic- convective systems (MCC) are triggered by moist  
scale (Table 3), with maximum densities in periods air masses frequently advancing poleward or  
3
.6 and 5.6 days (Fig. 12D). These results are in weak disturbances passing by in the summertime  
agreement with those of Bianchi (1994), wherein westerlies. These recurring systems also show  
a pioneering study using the Fourier spectrum considerable monthly and year to year variability  
analysis methodology, she found short-wave pollen but in some cases, they produce an MCC almost  
periods ranging from 24 hours to 3.7 days in the every other night. Moreover, O’Rourke (1990)  
atmosphere of Mar del Plata city (Argentina). already found that increasing wind speed and  
Unfortunately, the study did not comprise longer gustiness associated with convective rain events  
wavelengths.  
may be responsible for the increase of airborne  
Presumably, the medium to long synoptic waves pollen concentrations. These frequencies cover the  
are the ones that provide the greatest variability entire range of the synoptic frequencies analysed in  
and probably carry out the greatest modulation of this paper and could be the source of the claimed  
pollen dispersal and transport. For this reason, the coincidence between wind components and the  
density spectra of the airborne pollen concentration arboreal pollen mentioned above. As a result, this  
show similarities with those of the meteorological scale must be studied in more detail to understand  
variables analysed. This is an expected result due the processes involved in the intra seasonal  
to the strong association between airborne pollen variability of airborne pollen concentration,  
concentration and most of the meteorological dispersal, and transport as well as in the case of all  
variables reported in the literature (Vázquez et the other time scales.  
al., 2003; Altintaş et al., 2004; Majeed et al.,  
2
018). Some authors also confirm the association  
between synoptic-scale characteristics and airborne conclusions  
pollen concentrations (Gassmann & Pérez, 2006;  
Hernández-Ceballos et al., 2011). Hernández-  
This study presents the preliminary analysis  
Ceballos et al. (2011) found an association between of the relationship between the meteorological  
episodes of high concentration of olive pollen and variables and the airborne pollen concentration of  
the presence of synoptic systems in SW Spain. the mayor pollen types of a city in the agricultural  
Although they did not study their recurrence, their and livestock production center of Argentina.  
results show that they occur in periods between 3 The pollination periods show a delay in 2013  
and 10 days in agreement with our results. Makra compared to the previous year, presumably related  
et al. (2007) also found increases in airborne to a greater amount of cumulative heat units in  
282  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
2
2
012. However, the integral pollen for the period bibliogRaPhy  
013 was 1.4 times higher than 2012, a fact that  
is not explained by accumulated precipitation but ALTINTAŞ, D, U., G. B. KARAKOÇ, M. YILMAZ,  
by the time of day when the hydrometeors occur.  
Binned pollen concentrations show that the highest  
concentrations coincide with the urban location of  
the tree sources while the herbaceous ones show  
an association with a rural origin. Regarding the  
M. PINAR, S. G. KENDIRLI & H. ÇAKAN.  
2004. Relationship between Pollen Counts and  
Weather Variables in East-Mediterranean Coast of  
intra-seasonal variability, the highest proportion ARIZMENDI, C. M., J. R. SANCHEZ, N. E. RAMOS  
of the airborne pollen variance accumulates on the  
synoptic-scale (80 - 60%) with periods between 3  
and 10 days. During 2012 long waves predominated  
& G. I. RAMOS. 1993. Time series prediction  
with neural nets: Application to airborne pollen  
(> 5.5 days) while in 2013 medium waves prevailed  
(
3.9 - 5.5 days). Although the greatest variability AZNARTE, J. L. M., J. M. BENÍTEZ SÁNCHEZ, D.  
is concentrated in long-term changes, seasonal  
and minor timescales changes are usually the most  
relevant for predicting the concentration of airborne  
pollen. Knowledge of the contribution of these  
timescales is essential to build alert systems as  
therapeutic support for the treatment of respiratory  
allergies.  
N. LUGILDE, C. DE LINARES FERNÁNDEZ,  
C. DÍAZ DE LA GUARDIA & F. A. SÁNCHEZ.  
2007. Forecasting airborne pollen concentration  
time series with neural and neuro-fuzzy models.  
BASSETT, J., C. W. CROMPTON & D. W.  
WOODLAND. 1977. The biology of Canadian  
BAUER, H., H. GIEBL, R. HITZENBERGER, A.  
KASPER-GIEBL, G. REISCHL, F. ZIBUSCHKA  
& H. PUXBAUM. 2003. Airborne bacteria as  
authoRscontRibutions  
All the authors contributed to the study  
design. Pollen analysis was performed by CFP.  
Meteorological analysis was performed by MIG  
and AGU. Fourier analysis was performed by MC.  
The first draft was written by CFP and all authors BIANCHI, M. M. 1992. Calendario polínico de la  
make comments of this version. All authors read  
ciudad de Mar del Plata (agosto 1987 - agosto  
and approved the final manuscript.  
1989). Arch. argent. alerg. Inmunol. Clín. 23:  
7
3-86.  
BIANCHI, M. M. 1994. El muestreo aerobiológico en  
Mar del Plata: Aportes de una nueva metodología  
al análisis de polen. Su aplicación en el  
diagnóstico de la polinosis. Academia Nacional  
de Ciencias, Buenos Aires. Monografía N°10.  
acKnowledgments  
We appreciate the support of the company  
SanCor Cooperativa de Seguros Ltda. who was  
responsible for the installation of the Burkard trap BIANCHI, M. M., C. M. ARIZMENDI & J. R.  
and the logistics for the transport of the samples to  
be analyzed. Especially to the Sunchales weather  
station personnel who were in charge of the  
Burkard trap operation. Without their collaboration,  
SANCHEZ. 1992. Detection of chaos: New  
approach to atmospheric pollen time-series  
this work would not have been possible. We BRIGHETTI, M. A., C. COSTA, P. MENESATTI,  
gratefully thank the National Weather Service who  
provide the meteorological data for this study. This  
work was carried out with funds from the Agencia  
Nacional de Promoción Científica y Tecnológica  
grants: PICT 2008 - 1739 and PICT 2016 -0592  
given to AGU and CFP respectively.  
F. ANTONUCCI, S. TRIPODI  
&
A.  
TRAVAGLINI. 2014. Multivariate statistical  
forecasting modeling to predict Poaceae pollen  
critical concentrations by meteoclimatic data.  
Aerobiologia 30: 25-33.  
https://doi.org/10.1007/s10453-013-9305-3  
283  
Bol. Soc. Argent. Bot. 56 (3) 2021  
CADMAN, A., J. DAMES & A. P. S. TERBLANCHE.  
ESKRIDGE, R. E., J. Y. KU, S. T. RAO, P. S. PORTER  
& I. G. ZURBENKO. 1997. Separating Different  
Scales of Motion in Time Series of Meteorological  
FERNÁNDEZ-RODRÍGUEZ, S., P. DURÁN-  
BARROSO, I. SILVA-PALACIOS, R. TORMO-  
MOLINA, J. M. MAYA-MANZANO & A.  
GONZALO-GARIJO. 2016. Regional forecast  
model for the Olea pollen season in Extremadura  
1
994. Airspora concentrations in the Vaal Triangle:  
monitoring and potential health effects. 1, pollen.  
Suid-Afrikaanse Tydskrif vir Wetenskap 90: 607-610.  
CABRERA, A. L. 1976. Regiones fitogeográficas  
argentinas. En: W. F. Kugler (ed.), Enciclopedia  
da  
Argentina de Agricultura y Jardinería. Tomo 2. 2  
edición. pp. 1-85. Acme, Buenos Aires.  
COMTOIS, P. 1998. Statistical analysis of aerobiological  
data. In: Mandrioli et al. (eds), Methods in  
Aerobiology. pp. 218-257. Pitagora Editrice, Bologna.  
COMTOIS, P. 2000. The gamma distribution as the true  
aerobiological probability density function (PDF).  
FRENGUELLI, G., E. BRICCHI, B. ROMANO,  
G. MINCIGRUCCI, F. FERRANTI & E.  
DAMIALIS, A., G. GIOULEKAS, CH. LAZOPOULOU,  
CH. BALAFOUTIS & D. VOKOLI. 2005. Transport  
of airborne pollen into the city of Thessaloniki: the  
effects of wind, direction speed and persistence. Int.  
ANTOGNOZZI. 1992. The role of air temperature  
in determining dormancy release and flowering  
FRENGUELLI, G., F. TH. M. SPIEKSMA, E. BRICCHI,  
B. ROMANO, G. MINCIGRUCCI,A. H. NIKKELS,  
W. DANKAART & F. FERRANTI. 1991. The  
influence of air temperature on the starting date of the  
GALÁN, C., J. EMBERLIN, E. DOMINGUEZ, R.  
H. BRYANT & F. VILLAMANDOS. 1995. A  
comparative analysis of daily variations in the  
Gramineae pollen counts at Córdoba, Spain and  
DAMIALIS, A., E. KAIMAKAMIS, M. KONOGLOU,  
I. AKRITIDIS, C. TRAIDL-HOFFMANN & G.  
GIOULEKAS. 2017. Estimating the abundance  
of airborne pollen and fungal spores at variable  
DRIESSEN, M. N. B. M., R. M. A. VAN HERPEN, R.  
P. M. MOELANDS & F. TH. M. SPIEKSMA. 1989.  
Prediction of the start of the grass pollen season  
3
GALÁN, C., M. J. FUILLERAT, P. COMTOIS &  
E. DOMINGUEZ-VILCHES. 1998. Bioclimatic  
factors affecting daily Cupressaceae flowering in  
DRIESSEN, M. N. B. M., R. M. A. VAN HERPEN & L.  
O. M. J. SMITHUIS. 1990. Prediction of the start of  
the grass pollen season for the southern part of the  
GARCÍA-MOZO, H., C. GALÁN, J. BELMONTE,  
D. BERMEJO, P. CANDAU, C. DÍAZ DE LA  
GUARDIA, B. ELVIRA, B. GUTIÉRREZ, V, JATO,  
I. SILVA, M. M. TRIGO, R. VALENCIA & I.  
CHUINE. 2009. Predicting the start and peak dates  
of the Poaceae pollen season in Spain using process-  
GASSMANN, M. I. & C. F. PÉREZ. 2006. Trajectories  
associated to regional and extra-regional pollen  
transport in the southeast of Buenos Aires province,  
Mar del Plata (Argentina). Int. J. Biometeorol. 50:  
EDMONDS, R. L. (ed.) 1979. Aerobiology: The  
Ecological Systems Approach. US/IBP Synthesis  
Series 10. Hutchinson & Ross, Inc. Dowden.  
EMBERLIN,J.C.,J.NORRIS-HILL&R.H.Bryant.1990.  
EMBERLIN, J., S. JONES, J. BAILEY, E. CAULTON,  
J. CORDEN, S. DUBBELS, J. EVANS, N.  
MCDONAGH, W. MILLINGTON, J. MULLINS,  
R. RUSSEL & T. SPENCER. 1994. Variation in the  
start of the grass pollen season at selected sites in  
284  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
GATZ, D. F. &A. N. DINGLE. 1963. Washout of ragweed  
GULEV, S. K., T. JUNG & E. RUPRECHT. 2002.  
Climatology and Interannual Variability in the  
Intensity of Synoptic-Scale Processes in the North  
in Hirst-Burkard pollen and spore trap. Grana 20:  
KAWASHIMA,S.&Y.TAKAHASHI.1999.Animproved  
simulation of mesoscale dispersion of airborne cedar  
KELLY, D. 1994. The evolutionary ecology of mast  
HERNÁNDEZ-CEBALLOS, M. A., H. GARCÍA-  
MOZO, J. A. ADAME, E. DOMÍNGUEZ-  
VILCHES, B. A. DE LA MORENA, J. P.  
BOLÍVAR & C. GALÁN. 2011. Synoptic and  
meteorological characterisation of olive pollen  
transport in Córdoba province (south-western  
HEUSSER, C. J. 1971. Pollen and spores of Chile. Univ.  
KOENIG, W. D. & J. M. H. KNOPS. 2005. The  
Mystery of Masting in Trees: Some trees reproduce  
synchronously over large areas, with widespread  
KOTTEK, M., J. GRIESER, CH. BECK, B. RUDOLF &  
F. RUBEL. 2006. World map of the Köppen - Geiger  
LATORRE, F. 1997. Comparison between phenological  
and aerobiological patterns of some arboreal species  
HJELMROOS, M. 1992. Long-distance transport of  
Betula pollen grains and allergenic symptoms.  
HIRST, J. M. 1952. An automatic volumetric spore trap.  
HOGREFE, C., S. VEMPATY, S. T. RAO & P. S.  
PORTER. 2003. A comparison of four techniques  
for separating different time scales in atmospheric  
LATORRE, F. 1999a. El polen atmosférico como  
indicador de la vegetación y de su fenología  
LATORRE, F. 1999b. Differences between airborne  
pollen and flowering phenology of urban trees with  
reference to production, dispersal and interannual  
climate variability. Aerobiologia 15: 131-141.  
LATORRE, F. & M. A. CACCAVARI. 2010. Diversidad  
polínica en el aire de Diamante (Entre Ríos,  
Argentina). Scientia Interfluvius 1: 7-17.  
HUFFMAN, J. A., C. POHLKER, A. J. PRENNI, et al.,  
2
013. High concentrations of biological aerosol  
particles and ice nuclei during and after rain. Atmos.  
Chem. Phys. 13: 1767-1793.  
ISAGI, Y., K. SUGIMURA, A. SUMIDA & H. ITO.  
LEJOLY-GABRIEL, M. 1978. Recherches écologiques  
surlapluiepolliniqueenBelgique. ActaGeographica  
Lovaniensia 13: 1-279.  
1
997. How does masting happen and synchronize?  
JANZEN, D. H. 1976. Why bamboos wait so long to  
LEVETIN, E. & P. K. VAN DE WATER. 2003. Pollen  
count forecasting. Immunology and allergy clinics of  
JATO, V., A. DOPAZO & M. J. AIRA. 2002. Influence  
of precipitation and temperature on airborne pollen  
concentration in Santiago de Compostela (Spain).  
KÄPYLÄ, M. & A. PENTTINEN. 1981. An evaluation  
of the microscopical counting methods of the tape  
LEWIS, J. P. & M. B. COLLANTES. 1973. El Espinal  
LIEM, A. S. N. & J. GROOT. 1980. Anthesis and pollen  
dispersal of Holcus lanatus, Festuca rubra and Poa  
285  
Bol. Soc. Argent. Bot. 56 (3) 2021  
LO, E. & E. LEVETIN. 2007. Influence of meteorological  
conditions on early spring pollen in the Tulsa  
atmosphere from 1987-2006. J. Allergy Clin.l  
NILSSON, S. & S. PERSSON. 1981. Tree pollen spectra  
in the Stockholm region (Sweden), 1973-1980.  
NORRIS-HILL, J. 1998. A method to forecast the start  
of Betula, Platanus and Quercus pollen seasons in  
MAJEED, H. T., C. PERIAGO, M. ALARCÓN & J.  
BELMONTE. 2018. Airborne pollen parameters  
and their relationship with meteorological variables  
MAKRA, L., M. JUHÁSZ, J. MIKA, A. BARTZOKAS,  
R. BÉCZI & Z. SÜMEGHY. 2007. Relationship  
between the Péczely’s large‐scale weather types and  
airborne pollen grain concentrations for Szeged,  
O’ROURKE, M. K. 1990. Pollen re-entrainment:  
contributions to the pollen rain in an arid  
OYARZABAL, M., J. CLAVIJO, L. OAKLEY, F.  
BIGAZOLI, P. TOGNETTI, I. BARBERIS, H. M.  
MATURO, R. ARAGÓN, P. I. CAMPANELLO,  
D. PRADO, M. OESTERHELD & R. J. C. LEÓN.  
2018. Unidades de vegetación de la Argentina. Ecol.  
MCDONALD, J. E. 1962. Collection and washout of  
MCDONALD, J. E. 1964. Pollen wettability as a factor  
MÄKINEN, Y. 1977. Correlation of atmospheric spore  
PATHIRANE, L. 1975. Graphical determination of the  
main pollen season. Pollen Spores 17: 609-610.  
PÉREZ, C. F. 2000. Caracterización de la nube polínica  
y determinantes meteorológicos de la dispersión  
del sistema urbano-rural de Mar del Plata. Tesis  
doctoral. Universidad Nacional de Mar del Plata,  
Mar del Plata. Argentina.  
PÉREZ, C. F., M. I. GASSMANN & M. Covi. 2009.  
An evaluation of the airborne pollen-precipitation  
relationship with the superposed epoch method.  
PÉREZ, C. F., M. I. GASSMANN, N. TONTI & L.  
CURTO. 2020b. Panorama sobre la producción,  
el transporte y depósito de aerosoles de origen  
biológico. Meteorologica 45: 1-24.  
PÉREZ, C. F., M. I. GASSMANN, G. A. ULKE & R.  
MERINO. 2020a. Diversidad polínica atmosférica  
en la ciudad de Sunchales: agosto - noviembre 2012,  
agosto-diciembre 2013. Bol. Soc. Argent. Bot. 55:  
MARKGRAF, V. & H. L. D’ANTONI. 1978. Pollen  
flora of Argentina. Modern spore and pollen types  
of Pteridophyta, Gymnospermae and Angiospermae.  
The Univ. Arizona Press, Tucson. AZ.  
MARLETTO, V., G. P. BRANZI & M. SIROTTI. 1992.  
Forecasting flowering dates of lawn species with air  
temperature: application boundaries of the linear  
MASAKA, K. & SH. MAGUCHI. 2001. Modeling the  
masting behavior of Betula platyphylla var. japonica  
MIYAZAKI, Y. 2013. Dynamics of internal carbon  
resources during masting behavior in trees. Ecol.  
MORELLO, J., S. D. MATTEUCCI, A. F. RODRÍGUEZ  
PETERNEL, R., L. SRNEC, J. ČULIG, K. ZANINOVIĆ,  
B. MITIĆ & I. VUKUŠIĆ. 2004.Atmospheric pollen  
season in Zagreb (Croatia) and its relationship with  
temperature and precipitation. Int. J. Biometeorol.  
&
M. E. SILVA. 2012. Ecorregiones y complejos  
ecosistémicos argentinos. Capítulo 11: Espinal. 1era  
ed. Orientación gráfica editora, Buenos Aires.  
MULLENDERS, W., M. DIRICKX, D. VAN DER  
HAEGEN, Y. BASTIN-SERVAIS & M. DESAIR  
COREMANS. 1972. La pluie pollinique à Louvain  
PIRE, S. M., L. M. ANZÓTEGUI & G. A. CUADRADO.  
(Eds.) 1998. Flora polínica del Nordeste Argentino.  
Volumen I. EUDENE-UNNE. Corrientes.  
-
Heverlee en 1971. Louvain Medical 91: 159-176.  
286  
C. F. Pérez et. al. - Seasonal and intraseasonal pollen variations in Sunchales  
PIRE, S. M., L. M. ANZÓTEGUI & G. A. CUADRADO.  
Eds.) 2001. Flora polínica del Nordeste Argentino.  
(
Volumen II. EUDENE-UNNE. Corrientes.  
THOMPSON, R. S., K. H. ANDERSON & P. J.  
BARTLEIN. 2000. Atlas of relations between  
climatic parameters and distributions of important  
trees and shrubs in North America — Hardwoods.  
U.S. Geological Survey Professional Paper 1650-  
VÁZQUEZ, L. M., C. GALÁN & E. DOMÍNGUEZ-  
VILCHES. 2003. Influence of meteorological  
parameters on olea pollen concentrations in Córdoba  
VELASCO, I. & J. M. FRITSCH. 1987. Mesoscale  
convective complexes in the Americas. J. Geophys.  
RANTA, H., A. OKSANEN, T. HOKKANEN, K.  
BONDESTAM & S. HEINO. 2005. Masting by  
Betula-species; applying the resource budget model  
to north European data sets. Int. J. Biometeorol. 49:  
SCRIVEN, R. A. & B. E. A. FISHER. 1975. The  
long range transport of airborne material and its  
removal by deposition and washout. I. General  
SEELEY, S. D., J. L. ANDERSON, J. W. FRISBY &  
M. G. WEEKS. 1996. Temperature characteristics  
of anthesis phenology of deciduous fruit trees. Acta  
SKJØTH, C. A., T. BECKER, P. V. ØRBY, C. GEELS,  
V. SCHLÜNSSEN, T. SIGSGAARD, J. H.  
BØNLØKKE, J. SOMMER, P. SØGAARD & O.  
HERTEL. 2010. Urban sources caused elevated grass  
pollen concentrations. Dissertation, 9th International  
Congress on Aerobiology. Buenos Aires.  
SMITH, M. & J. EMBERLIN. 2006. A 30-day-ahead  
forecast model for grass pollen in north London,  
SOLMAN, S. A. & C. G. MENÉNDEZ. 2002. ENSO-  
Related Variability of the Southern Hemisphere  
Winter Storm Track over the Eastern Pacific-Atlantic  
VOUKANTSIS, D., K. KARATZAS, S. JAEGER,  
U. BERGER & M. SMITH. 2013. Analysis and  
forecasting of airborne pollen-induced symptoms  
with the aid of computational intelligence methods.  
WILKS, D. S. 2011. Statisticalmethodsintheatmospheric  
sciences. International Geophysics Series 100, 3rd  
ed. Elsevier Academic Press. Amsterdam, Boston,  
Heilderberg, London, New York, Oxford, Paris, San  
Diego, San Francisco, Singapore, Sydney, Tokyo.  
ZALOM, F. G., P. B. GOODELL, L. T. WILSON, W.  
W. BARNETT & W. J. BENTLEY. 1983. Degree-  
days: the calculation and use of heat units in pest  
management. Leaflet No. 21373. pp 2-10. Division  
of Agriculture and Natural Resources. Berkeley CA,  
94720: University of California.  
STACH, A., J. EMBERLIN, M. SMITH, B. ADAMS-  
GROOM & D. MYSZKOWSKA. 2008. Factors  
that determine the severity of Betula spp. pollen  
seasons in Poland (Poznań and Kraków) and the  
United Kingdom (Worcester and London). Int. J.  
ZHANG, Y., L. BIELORY, T. CAI, Z. MI & P.  
GEORGOPOULOS. 2015. Predicting onset and  
duration of airborne allergenic pollen season in the  
287