Balinese Y-chromosome perspective on the peopling of Indonesia: genetic contributions from pre-neolithic hunter-gatherers, Austronesian farmers, and Indian traders

The island of Bali lies near the center of the southern chain of islands in the Indonesian archipelago, which served as a stepping-stone for early migrations of hunter-gatherers to Melanesia and Australia and for more recent migrations of Austronesian farmers from mainland Southeast Asia to the Pacific. Bali is the only Indonesian island with a population that currently practices the Hindu religion and preserves various other Indian cultural, linguistic, and artistic traditions (Lansing 1983). Here, we examine genetic variation on the Y chromosomes of 551 Balinese men to investigate the relative contributions of Austronesian farmers and pre-Neolithic hunter-gatherers to the contemporary Balinese paternal gene pool and to test the hypothesis of recent paternal gene flow from the Indian subcontinent. Seventy-one Y-chromosome binary polymorphisms (single nucleotide polymorphisms, SNPs) and 10 Y-chromosome-linked short tandem repeats (STRs) were genotyped on a sample of 1,989 Y chromosomes from 20 populations representing Indonesia (including Bali), southern China, Southeast Asia, South Asia, the Near East, and Oceania. SNP genotyping revealed 22 Balinese lineages, 3 of which (O-M95, O-M119, and O-M122) account for nearly 83.7% of Balinese Y chromosomes. Phylogeographic analyses suggest that all three major Y-chromosome haplogroups migrated to Bali with the arrival of Austronesian speakers; however, STR diversity patterns associated with these haplogroups are complex and may be explained by multiple waves of Austronesian expansion to Indonesia by different routes. Approximately 2.2% of contemporary Balinese Y chromosomes (i.e., K-M9*, K-M230, and M lineages) may represent the pre-Neolithic component of the Indonesian paternal gene pool. In contrast, eight other haplogroups (e.g., within H, J, L, and R), making up approximately 12% of the Balinese paternal gene pool, appear to have migrated to Bali from India. These results indicate that the Austronesian expansion had a profound effect on the composition of the Balinese paternal gene pool and that cultural transmission from India to Bali was accompanied by substantial levels of gene flow.     

Origin, diffusion, and differentiation of Y-chromosome haplogroups E and J: inferences on the neolithization of Europe and later migratory events in the Mediterranean area

The phylogeography of Y-chromosome haplogroups E (Hg E) and J (Hg J) was investigated in >2400 subjects from 29 populations, mainly from Europe and the Mediterranean area but also from Africa and Asia. The observed 501 Hg E and 445 Hg J samples were subtyped using 36 binary markers and eight microsatellite loci. Spatial patterns reveal that (1). the two sister clades, J-M267 and J-M172, are distributed differentially within the Near East, North Africa, and Europe; (2). J-M267 was spread by two temporally distinct migratory episodes, the most recent one probably associated with the diffusion of Arab people; (3). E-M81 is typical of Berbers, and its presence in Iberia and Sicily is due to recent gene flow from North Africa; (4). J-M172(xM12) distribution is consistent with a Levantine/Anatolian dispersal route to southeastern Europe and may reflect the spread of Anatolian farmers; and (5). E-M78 (for which microsatellite data suggest an eastern African origin) and, to a lesser extent, J-M12(M102) lineages would trace the subsequent diffusion of people from the southern Balkans to the west. A 7%-22% contribution of Y chromosomes from Greece to southern Italy was estimated by admixture analysis.     

A multiscale analysis of ecosystem services supply in the NW Iberian Peninsula from a functional perspective

In recent years, the assessment of ecosystem services (ES) supply has been based on the use of Land Use/Land Cover (LULC) data as proxies for spatial representation of ecosystems. Nevertheless, some shortcomings of this method, such as uncertainties derived from generalization of the ecosystem types and assumptions of invariance across spatial scales, indicate the need for new approaches. Such approaches could be aimed at improving knowledge of the relationships between ecosystem services and landscape structure and the spatial characteristics of ES patterns. In this study, we propose an integrative approach that involves the generation and analysis of continuous maps representing the supply of five ES potentially related to the amount of biomass. Five remote sensing images of the Northwestern Iberian Peninsula, obtained with Landsat-5 TM, were used to generate a proxy for net primary production by combining the normalized difference vegetation index (NDVI) of each image to calculate a ΣNDVI index that could act as a potential indicator of some ecosystem services. This information was combined with three variables – terrain slope, population density and occurrence of protected areas – to produce spatial models for the five ES and eventually a series of five supply maps. Food, materials and energy provision services showed a clustered pattern, with high supply values in flat zones and areas with high population densities. In contrast, mass flow and climate regulation services were more widely distributed throughout the study area. The five ecosystem service patterns were analyzed at different scales by two methods: lacunarity and four term local quadrat variance (4TLQV) analysis. These methods revealed differences in the spatial pattern: lacunarity analysis was useful for detection of scale thresholds at the local level, whereas 4TLQV was more sensitive to scale thresholds at larger spatial levels. Thus, the variance analysis yielded higher values for larger windows sizes, particularly for provisioning services. The results demonstrated the suitability of the proposed approach for the spatially explicit modeling of ecosystem services, avoiding the uncertainty of other assessments such as those based on LULC data, and for the exploratory analysis of ES supply from a spatial point of view.     

Climate change and bird phenology: a long-term study in the Iberian Peninsula

Many studies in recent years have demonstrated long‐term temporal trends in biological parameters that can only be explained by climate change. Bird phenology has received great attention, as it studies one of the most conspicuous, popular, and easily observable phenomena in nature. There are many studies of long‐term changes in spring arrival dates, most of which concur with earlier records from the last few decades. However, few data are available for autumn departures or length of stays. Furthermore, existing data offer an equivocal picture. In this study, we analysed a huge database of about 44 000 records for five trans‐Saharan bird species (Ciconia ciconia, Cuculus canorus, Apus apus, Hirundo rustica and Luscinia megarhynchos). Data were collected from over 1300 sites around Spain during the period 1944–2004. Common spring arrival patterns were found in all species. Spring arrival dates have tended to advance since the mid‐1970s. Current dates are similar to those from the 1940s (except for C. ciconia). Thus, the advance of spring migration over the last three decades could be seen as a return to the initial timing of arrival dates, after abnormally delayed arrivals during the 1970s. A strong negative relationship with temperature in Spain at arrival time was observed in all species. A negative relationship with the Sahel Index (a measurement of precipitation in the African Sahel area during the rainy season) for the previous year was also found in C. canorus, A. apus and H. rustica. Regarding autumn departures, all species showed common interdecadal fluctuations, but only H. rustica is leaving earlier Spain at present. All species departed earlier in years that had higher temperatures during their reproductive period. However, only for H. rustica the relation between Spanish temperatures at departure time and the last sightings of individuals was significant. A heterogeneous temporal response for the length of stay was also found: C. ciconia increased, A. apus did not change and H. rustica decreased its stay. This is the first study, based on an extensive bird phenology observational network covering a large region, that shows the most complete and thorough analysis available for the Mediterranean region.     

High-resolution analysis of human Y-chromosome variation shows a sharp discontinuity and limited gene flow between northwestern Africa and the Iberian Peninsula

In the present study we have analyzed 44 Y-chromosome biallelic polymorphisms in population samples from northwestern (NW) Africa and the Iberian Peninsula, which allowed us to place each chromosome unequivocally in a phylogenetic tree based on >150 polymorphisms. The most striking results are that contemporary NW African and Iberian populations were found to have originated from distinctly different patrilineages and that the Strait of Gibraltar seems to have acted as a strong (although not complete) barrier to gene flow. In NW African populations, an Upper Paleolithic colonization that probably had its origin in eastern Africa contributed 75% of the current gene pool. In comparison, approximately 78% of contemporary Iberian Y chromosomes originated in an Upper Paleolithic expansion from western Asia, along the northern rim of the Mediterranean basin. Smaller contributions to these gene pools (constituting 13% of Y chromosomes in NW Africa and 10% of Y chromosomes in Iberia) came from the Middle East during the Neolithic and, during subsequent gene flow, from Sub-Saharan to NW Africa. Finally, bidirectional gene flow across the Strait of Gibraltar has been detected: the genetic contribution of European Y chromosomes to the NW African gene pool is estimated at 4%, and NW African populations may have contributed 7% of Iberian Y chromosomes. The Islamic rule of Spain, which began in a.d. 711 and lasted almost 8 centuries, left only a minor contribution to the current Iberian Y-chromosome pool. The high-resolution analysis of the Y chromosome allows us to separate successive migratory components and to precisely quantify each historical layer.     

Review of the Corticaria sylvicola group (Coleoptera: Latridiidae), with a description of two new species from the Iberian Peninsula

Summary. This article describes two new species, Corticaria antonioi n. sp. and Corticaria lucasi n. sp., from the Iberian Peninsula. A key to the species of the sylvicola group is provided.     

Genetic diversity of the Khakass gene pool: Subethnic differentiation and the structure of Y-chromosome haplogroups

The structure of Khakass gene pool has been investigated: Y-chromosome haplogroup compositions and frequencies were described in seven population samples of two basic subethnic groups, Sagai and Kachins, from three geographically separated regions of the Khakass Republic. Eight haplogroups were detected in the Khakass gene pool: C3, E, N*, N1b, N1c, R1a1a, and R1b1b1. The haplogroup spectra and the genetic diversity by haplogroups and YSTR haplotypes differed significantly between Sagai and Kachins. Kachins had a low level of gene diversity, whereas the diversity of Sagai was similar to that of other South-Siberian ethnic groups. Sagai samples from the Askizskii district were very similar to each other, and so were two Kachin samples from the Shirinskii district, while Sagai samples from the Tashtypskii district differed considerably from each other. The contribution of intergroup differences among ethnic groups was high, indicating significant genetic differentiation among native populations in Khakassia. The Khakass gene pool was strongly differentiated both by haplogroup frequencies and by YSTR haplotypes within the N1b haplogroup. The frequencies of YSTR haplotypes within the chromosome Y haplogroups N1b, N1c, and R1a1 were determined and their molecular phylogeny was investigated. Factor and cluster analysis, as well as AMOVA, suggest that the Khakass gene pool is structured by territory and subethnic groups.     

Morphological and physiological differences between two morphotypes of Zostera noltii Hornem. from the south-western Iberian Peninsula

The morphological and physiological differences between two morphotypes of Z. noltii Hornem. were studied in the intertidal meadows on the south-western Iberian Peninsula (Palmones river estuary and Ria Formosa). A small-leaved morphotype (SM) grows mainly at high intertidal sites, meadow edges or in recently deposited sandbanks, whereas a large-leaved morphotype (LM) generally thrives in well-structured beds or in deeper places. This study deals with the morphological, biochemical and physiological differences between these morphotypes as well as the ecological implications of the occurrence of different morphotypes in the same meadow. Shoot length, leaf width, rhizome internode length, roots per node, root length, leaf nutrient and pigment contents, and photosynthetic rates of both morphotypes were compared. The below-ground architecture (root and rhizome complex) of both morphotypes was more developed in sites characterized by higher hydrodynamics and/or a lower nitrogen content in sediments. Both morphotypes showed similar values for photosynthetic efficiency, dark respiration rate and compensation irradiance. On the other hand, the net photosynthetic capacity was much greater (5-fold) for the SM. This difference could explain the greater growth rate and faster leaf turnover rate of the SM compared with the LM. The occurrence of the SM in newly settled areas (and in the meadow edges) could be explained on the basis of its higher growth rate, which would allow a faster spreading of the meadow and/or better recovery after burial resulting from stormy weathers. Received: 20 December 1998 / Received in revised form: 21 April 1999 / Accepted: 23 April 1999     

Genetic diversity of Khakassian gene pool: subethnic differensiation and the structure of Y-chromosome haplogroups,

The structure of Khakass gene pool has been investigated: compositions and frequencies of Y-chromosome haplogroups were described in seven population samples of two basic subethnic groups--Sagays and Kachins from three territorially distanced regions of Khakassia Republic. Eight haplogroups: C3, E, N*, N1b, N1c, R1a1a and R1b1b1 have been determined in Khakass gene pool. Significant differences between Sagays and Kachins were shown in haplogroup spectra and a level of genetic diversity in haplogroups and YSTR-haplotypes. Kachin samples are characterized by a low value of gene diversity, whereas the level of Sagay diversity is similar to that of other South-Siberian ethnoses. Sagay samples from Askizsky region are very similar to each other just as two Kachin samples from Shirinsky region, while Sagay samples from Tashtypsky region greatly differ from each other. A great portion of intergroup differences was determined among different ethnic groups, which testifies to significant genetic differentiation of native populations in Khakassia. Khakass gene pool is greatly differentiated both in haplogroup frequencies and in YSTR-haplotypes within N1b haplogroup. Frequencies and molecular phylogenesis of YSTR-haplotypes were revealed within N1b, N1c and R1a1 haplogroups of Y-chromosome. We carried out comparative analysis of the data obtained. The results of factor, cluster and dispersion analyses are evidence of structuredness of Khakass gene pool according to territorial-subethnic principle.     

Anisian floras from the NE Iberian Peninsula and Balearic Islands: A synthesis

This paper focuses on the diversity and palaeontological significance of the Anisian floral record in the Triassic of the northeastern Iberian Peninsula. A summary of published information is followed by new records from macrofloral localities at Rodanas (Aragonese Branch of the Iberian Range) and at Maya del Baztán (Basque-Cantabrian Domain, Pyrenees). Both of these new localities also yielded three Anisian microfloral assemblages. These records provide new evidence of Anisian (basal Middle Triassic) floras in Spain. They are found to be somewhat similar to the classical flora of the Grès à Voltzia Formation (Upper Buntsandstein) of the northern Vosges in north-eastern France, of whose age has been shown to be early Anisian.     

Devonian floral assemblages and plant megafossils from the Iberian Peninsula: A review

This paper presents a review and critical analysis of the literature on Devonian floras of the Iberian Peninsula. Although the known outcrops of Devonian strata in the Iberian Peninsula are marine, in some cases, a few fragmentary remains of vascular plants are associated with faunal remains. Records include largely specimens from the Lower Devonian of Barrancos (Alentejo, Portugal) and the Upper Devonian of Sierra de Hornachos in Badajoz province, southwest Spain; the remainder consists of drifted plant fragments from scattered sites in the Iberian Peninsula ranging in age from Lochkovian to Upper Devonian-Earliest Carboniferous. The vegetation inferred for the Lower Devonian of the Iberian Peninsula is mainly based on palynological data and corresponds to herbaceous types characterised by bryophytes, rhyniophytes (Horneophyton, Cooksonia, Rhynia), trimerophytes (Psilophyton, Pertica and Hostinella), primitive lycophytes (Drepanophycus) and incertae sedis such as Nothia and Chaleuria, all flora that developed near the coast in low-lying and, at least periodically, wet areas. In the Middle Devonian, two vegetation strata can be recognised: herbaceous (Psilophyton) and semi-arboreal (Cladoxylales). Although three levels of vegetation in the Upper Devonian, have been described from outcrops worldwide, the scarce available data from the Iberian Peninsula only indicate an arborescent lycopsid vegetation and species with uncertain botanical affinity such as Sphenopteridium keilhauii Nathorst.     

Taxonomic notes on Trechini and description of a new hypogean species from the Iberian Peninsula (Coleoptera: Carabidae: Trechinae)

In this contribution, a new pubescent Trechus species for the Iberian Peninsula is described, and the use of some morphological traits in the systematic of Trechini are discussed. Micropubescence is common in endogean and troglobite species which are closely related with the “terrestrial-phreatic habitat”. It probably enhances survival in swampy environments through the retention of air bubbles in immersion conditions and promoting flotation. Neither this trait, anophthalmy nor inner sac of aedeagus without sclerotized pieces can be used to support supraspecific taxa. Thus, we propose the formal synonymy of Hydrotrechus with Trechus [Hydrotrechus syn. nov. of Trechus]. To avoid secondary homonymy, we propose the name Trechus triamicorum nom. nov. for Hydrotrechus cantabricus Carabajal, García & Rodríguez 1999 [already occupied by Trechus cantabricus Jeannel 1927, synonym of Trechus distigma Kiesenwetter 1851]. We also propose the synonymization of the subgenus Trichapoduvalius with Apoduvalius [Trichapoduvalius syn. nov. of Apoduvalius]. The new hypogean species with pubescent elytra, Trechus cifrianae sp. nov., is described. The morphology of the species suggests that it probably inhabits the Mesovoid Shallow Substratum (MSS) or the fissure network (mesocaverns and microcaverns) of the cave where the only individual was found. The structure of internal female genitalia suggests a close relationship between T. cifrianae sp. nov. and T. carrilloi Toribio & Rodríguez 1997.     

Effects of exotic and native tree leaf litter on soil properties of two contrasting sites in the Iberian Peninsula

Aims

We assessed the effects of native and exotic tree leaf litter on soil properties in two contrasting scenarios. The native Quercus robur and Pinus pinaster tree species coexist with the aliens Eucalyptus globulus and Acacia dealbata in acid soils of NW Spain. The native trees Fraxinus angustifolia and Ulmus minor coexist with the aliens Ailanthus altissima, Robinia pseudoacacia and Ulmus pumila in eutrophic basic riparian soils in Central Spain.

Methods

Four plastic trays per species were filled with homogenized top-soil of the site and covered with leaf litter. Before and after 9?months of incubation, litter mass, soil pH, organic matter, mineral and total N were measured. Available mineral N (NO ₃ ^? -N and NH ₄ ⁺ -N) was assessed every 2?months.

Results

Soil biological activity was higher in the basic than in the acid soil. Litter of the exotic trees tended to decompose less than litter of native species, probably due to the presence of secondary metabolites in the former. Soil pH, mineral and total N responded differently to different litter types, irrespective of their exotic or native origin (acid soil), or was similar across litter treatments (basic riparian soil). The similar response of the basic soil to the addition of different litter types may be due to the low contrast of litter quality between the species. E. globulus litter inhibitied soil microbial activity much more than the rest of the studied litter types, leading to a drastic impoverishment of N in soils.

Conclusion

Litter of exotic N-fixing trees (A. dealbata and R. pseudoacacia) did not increase soil N pools because of the inhibition of microbial activity by secondary compounds. Therefore, secondary metabolites of the litter played a major role explaining exotic litter impact on soil properties.     

Karyological and taxonomic notes on Ophrys (Orchidoideae, Orchidaceae) from the Iberian Peninsula

Karyological information on Iberian Ophrys species is very limited. This paper provides the haploid and diploid chromosome numbers of 11 taxa of sect. Pseudophrys and sect. Ophrys , both of which are well represented in the Iberian Peninsula, and two taxa from Tunisia. The first data on chromosome numbers for O. vasconica (2 n  = 72, 74), O. ficalhoana (2 n  = 36), O. picta (2 n  = 36), O. sphegifera ( n  = 18, 2 n  = 36, 38) and O. passionis (2 n  = 36) are also presented, confirming the stability of the chromosome number in Ophrys . In addition, populations of the group O. omegaifera ( O. dyris and O. vasconica ), together with tetraploidy, pentaploidy and the existence of aneuploid phenomena, are reported for the first time in Iberia. The basic diploid number is always 2 n  = 36. The karyotypes of several species were analysed. Evolutionary trends in Ophrys chromosomes are discussed. Taxonomic and phytogeographical details are provided on several species or groups of species from Iberia.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003 , 142 , 395−406.     

Spatial Distribution of Dorylaimid and Mononchid Nematodes from the Southeast Iberian Peninsula: Environmental Characterization of Chorotypes

The aim of this study was to determine the incidence of 18 environmental variables in the spatial distribution of 30 chorotypes (species groups with significantly similar distribution patterns) of dorylaimid and mononchid nematodes by means of logistic regression in a natural area in the southeastern Iberian Peninsula. Six variables (elevation, color chroma, clay content, nitrogen content, CaCO₃, and plant community associated) were the most important environmental factors that helped explain the distribution of chorotypes. The distribution of most chorotypes was characterized by some (one to three) environmental variables; only two chorotypes were characterized by five or more variables, and four have not been characterized.     

Genetic diversity within a caste population of India as measured by Y-chromosome haplogroups and haplotypes: subcastes of the Golla of Andhra Pradesh

The extent of population subdivision based on 15 Y-chromosome polymorphisms was studied in seven subcastes of the Golla (Karnam, Pokanati, Erra, Doddi, Punugu, Puja, and Kurava), who inhabit the Chittoor district of southern Andhra Pradesh, India. These Golla subcastes are traditionally pastoralists, culturally homogeneous and endogamous. DNA samples from 146 Golla males were scored for seven unique event polymorphisms (UEPs) and eight microsatellites, permitting allocation of each into haplogroups and haplotypes, respectively. Genetic diversity (D) was high (range, 0.9048-0.9921), and most of the genetic variance (>91%) was explained by intrapopulation differences. Median-joining network analysis of microsatellite haplotypes demonstrated an absence of any structure according to subcaste affiliation. Superimposition of UEPs on this phylogeny, however, did create some distinct clusters, indicating congruence between haplotype and haplogroup phylogenies. Our results suggest many male ancestors for the Golla as well as for each of the subcastes. Genetic distances among the seven subcastes, based on autosomal markers (short tandem repeats and human leukocyte antigens) as well as those on the chromosome Y, indicate that the Kurava may not be a true subcaste of the Golla. Although this finding is based on a very small Kurava sample, it is in accordance with ethnohistorical accounts related by community elders. The Punugu was the first to hive off the main Golla group, and the most recently separated subcastes (Karnam, Erra, Doddi, and Pokanati) fissioned from the Puja. This phylogeny receives support from the analysis of autosomal microsatellites as well as HLA loci in the same samples. In particular, there is a significant correlation (r = 0.8569; P = 0.0097) between Y-chromosome- and autosomal STR-based distances.     

DYS19 and DYS390 Y-STR polymorphism in the Iberian Peninsula: a multivariate analysis

Genetic polymorphism of two Y-specific short tandem repeats (DYS19 and DYS390) was investigated in six populations from the Iberian Peninsula (Andalusia, Castilla-La Mancha, Castilla-Leon, Extremadura, Galicia and South East Spain) comprising a total of 895 unrelated and native individuals, and a complete database of DYS19 and DYS390 allele frequency distributions in 34 world-wide populations collected from literature was analysed. DYS19 and DYS390 polymorphism was screened by automated fluorescence analysis of PCR-amplified labelled sample fragments performed with and ABI PRISM 377 Genetic Analyser. The degree of population differentiation was analysed using the STP Test to calculate G Statistic values. Correspondence Analysis based on the allelic frequencies of each locus and combining both was performed using the NTSYS-PC version 1.70 computer package. The diversity of the genetic profiles of gene frequencies suggests an important population heterogeneity in the Iberian Peninsula as a whole (DYS390 being particularly evident), which is corroborated after statistical analyses (G = 139.8457, p = 1.7822 x 10(-14) for DYS19, G = 116.0293, p = 4.6845 x 10(-12) for DYS390). However, multivariate analysis indicates a well defined cluster of the populations of the Central region, and sets them apart from the positions within which peripheral Iberian Peninsula populations are distributed. The Galician population shows trends which bring it closer to the positions throughout which European Atlantic populations are distributed. The results shown by the Central Iberian Peninsula seem to lend support to a model of settlement population stocks which came from the region of Castilla-Leon after the Islam invasions, whereas in the South-East populations the genetic record of Middle Eastern populations is still present, a consequence of the expansion of Islam in Southern Europe in the Middle Ages.     

Comparative study of the effect of distance on the daily and hourly pollen counts in a city in the south-western Iberian Peninsula

The airborne pollen concentration in the city of Badajoz was measured in two locations 2.9 km apart. The measurements were taken from January to June between 2009 and 2012 using Hirst-type volumetric aerobiological samplers. One sampler was placed at the Faculty of Science (FS) and the other at the Agricultural Engineering School (AES) of the University of Extremadura, Spain, on terraces located 16 and 6 m above ground, respectively. The two sets of hourly and daily pollen concentrations were compared regarding the meteorological parameters and the distribution of local pollen sources. A total of 46 pollen types were counted, with a mean total concentration of 43 pollen grains/m³ in the winter and 336 pollen grains/m³ in the spring. In the winter, pollen grains from (in decreasing order) Cupressaceae, Fraxinus–Phillyrea, Urticaceae spp., Alnus glutinosa and Urtica membranacea types represented 77 % of the total. In the spring, 89 % of the total was represented by pollen grains from (in decreasing order) Quercus, Poaceae, Olea, Pinaceae and Plantago. The FS/AES ratio was 0.57 in the winter and 1.31 in the spring. While a Wilcoxon test applied to the daily total concentration data showed statistically significant differences between the two sites, a correlation study based on the Spearman coefficient showed statistically significant correlations in both the winter and spring. The results were similar when comparing the separate pollen types, except for Urticaceae spp., which showed no statistically significant correlation. The meteorological data studied showed a statistically significant correlation with the daily concentrations. A comparison of the hourly concentration data showed no correspondence with the time of maximum concentration. The local distribution of pollen sources explained some of the differences found between the two sites. Overall, the results indicate that a single aerobiological sampler may be sufficiently representative to register the daily pollen grain data of an urban area of approximately 3 km or greater in diameter, although it underestimates the influence of heterogeneity in the distribution of the local flora.