87 research outputs found

    Aplicación de la geoestadística al estudio de la fenología floral de Vulpia geniculllta (L.) Link

    Get PDF
    XV lnternational A.P.L.E. Symposium of Palynolog

    Optimización de modelos predictivos a corto y largo plazo de polen de tipo quercus en distintas zonas climáticas

    Get PDF
    En este trabajo se han analizado, por un lado, datos: polínicos del tipo Quercus, bioclimáticos y meteorológicos de 14 localidades españolas del periodo 1992-2000. A partir de dichos datos se construyeron modelos de pronóstico para las principales características de la estación polínica de este género en la Península Ibérica: Inicio de la Estación, Concentraciones Diarias, Valor Pico, Día Pico e Indice Polínico Anual. Todos los modelos obtenidos se validaron para años de datos no incluidos en los mismos con excelentes resultados estadísticos. Destacaron las diferencias detectadas entre las variables predictoras que entraron en las ecuaciones propuestas para las localidades de la Región Mediterránea y las de la Región Eurosiberiana. Por otra parte se realizó el análisis del contenido polínico de un punto piloto con vegetación típica Mediterránea donde predominan las especies de hoja perenne del género Quercus, Quercus suber, Quercus coccifera y, fundamentalmente Quercus ilex subsp. Ballota. Este estudio se llevó a cabo durante los años 1998-2000. A su vez, en esta zona, se realizó un seguimiento fenológico tanto de las estructuras reproductoras como de los frutos de Quercus ilex subsp. Ballota (encina). Las concentraciones del tipo polínico Quercus en la zona, los datos de fenología floral y frutal, así como los datos meteorológicos del periodo de estudio se integraron para la creación de un modelo preliminar la previsión de cosecha en encina. Los primeros resultados de este estudio nos revelaron que existe una alta correlación entre datos polínicos y de producción frutal en esta especi

    A model to account for variations in holm-oak (Quercus ilex subsp. ballota) acorn production in southern Spain

    Get PDF
    One of the characteristics of holm-oak acorn production is its high variability among individuals and years. To examine the main causes of this fact, a study was conducted from 1998-2010 in a natural area of holm-oak in southern Spain, where floral phenology, fruit production, fruit size, airborne pollen emission and meteorology factors were analyzed with the ultimate aim of developing a model for forecasting holm-oak yield. Pollen emission during flowering season was the main factor determining the final acorn harvest, but also some meteorological variables played an important role in explaining acorn crop variations, especially humidity and temperature during the months of April and September. The reliability of the proposed model was externally validated using data not included in its construction; validation yielded acceptable results, with a minimum error of estimation. Our results appear to be very useful for planning cropping and pig feeding strategies. Further research could extend the use of airborne pollen counts in forest studies relating to anemophilous species, in order to optimize agricultural policie

    Analysis of the Orchidaceae Diversity in the Pululahua Reserve, Ecuador: Opportunities and Constraints as Regards the Biodiversity Conservation of the Cloud Mountain Forest

    Get PDF
    The Pululahua Geobotanical Reserve is a protected natural area in the cloud mountain forest of Ecuador, so rich in orchid species despite being a volcanic area still under threat of volcanic activity. A comparative biodiversity study of orchids was carried out in two different sectors, Chaupisacha (CH) and La Reventazón (LR). Data were collected in 1 ha plots in each sector, in which all the orchids found were counted and two individuals of each species were retained. Immature individuals were conserved in a plant nursery until flowering. In CH, there were 922 individuals grouped into 24 genera and 55 species, while LR had 9196 individuals grouped into 26 genera and 46 species; only 14 species were found in both sectors. Different density and diversity indexes were calculated. The density (ind./100 m2) of CH was 0.96, while that of LR was 185.92. Simpson’s diversity (1 − λ) attained CH 0.903 ± 0.01 and LR 0.85 ± 0.01. The orchid diversity measured by the Shannon-Wiener diversity index (H′) was 1.29 for CH, differing significantly from that of LR (H′ 1.02). The medium equity (Jaccard’s J′) found was 0.61 in CH and 90.78 in LR. Limitations as regards the natural dispersion of orchids seemed to favor endemism. Some species, such as Dracula felix and Restrepia guttulate, are threatened with disappearance from the wild or are vulnerable, as is the case for Epidendrum polyanthogastrium. A lack of information on the phenology and anthropic impacts in the area limit the conservation of species, signifying that new protected figures and seed banks are necessary, especially in CH, owing to its high diversity of orchids

    Long-term trends in atmospheric Quercus pollen related to climate change in southern Spain: A 25-year perspective

    Get PDF
    Long-term trends of atmospheric Quercus pollen recorded for 25 years (1995–2019) in southern Spain (Cordoba city, Andalusia region) have been studied to determine the influence of climate fluctuations and other anthropogenic factors on Mediterranean oak vegetation areas. Atmospheric pollen analysis revealed different changes on reproductive Quercus phenology through the study period. Pollination intensity showed an average cumulated value of the Main Pollen Season Integral of 12,832 Pollen * day/m3, with a high variability among years (±SD 8,048) and a significant rising trend of 771 pollen grains per year, being stronger in recent years (2014–2019). It was remarkable the high quantity of Quercus pollen grains detected out of the Main Pollen Season (703 Pollen * day/m3 ± SD 431), also increasing in recent years. Regarding Quercus phenology, results indicated as the main Quercus species in the area, Quercus ilex subsp. ballota (holm oak), Q. coccifera, Q. faginea and Q. suber, presented a gradually pollination during spring (from mid-March to early June), although a lengthening of the pollination season is observed in recent years. This phenomenon could be explained by the progressive delay in the pollination of Q. suber. Regarding climate factors, a decrease in rainfall, especially during winter and autumn was recorded, along with colder winters but warmer springs, summers, and autumns. These changes were significantly correlated with pollination timing and intensity. The climate parameters most affecting were those related to temperature and sunshine. However, the total annual pollen showed a significant negative correlation with the annual recorded rainfall. Results show that recent climatic change, among other factors, are leading to changes in the timing and intensity of the Quercus pollen season in the Mediterranean area

    Factors Driving Autumn Quercus Flowering in a Thermo-Mediterranean Area

    Get PDF
    The flowering period of plants is a critical time since it determines their reproductive success. Flowering is controlled by different factors including genetic regulation and environmental conditions. In the Mediterranean area, favourable conditions usually occur in spring, when most plant species flower including those of the Mediterranean Quercus genus. This paper reveals and analyses an unusual and lesser-known phenomenon occurring in the two main Mediterranean agroforestry ecosystems of South Europe, the Mediterranean forest and “dehesa”, that is, a second flowering occurring in autumn for the species Quercus ilex subsp. ballota (holm oak). The continuous pollen monitoring of the atmosphere in the city of Cordoba (southern Spain) for 25 years, together with field phenological observations in the area, has indicated that, apart from the main pollination period in spring, secondary flowerings also occasionally occur in this area, specifically in autumn. The present work examines these uncommon pollination events detected in the autumns of certain years with the aim of determining the main environmental factors that influence and control them. During the 25-year study period, there were 7 years in which a secondary Quercus flowering was detected in the area from the second half of October until the end of November. The univariate statistical analysis of the influence of environmental variables determined that the meteorological conditions in September were the most influential. Low mean temperatures, together with record rainfall in that month, led to autumn flowering events. The phenological characteristics of the spring pollen season were also influential. In the years with a shorter spring, the Quercus pollen season tended to present autumn flowerings. A multivariate adaptive regression splines (MARS) model was built to explain the effects of the different variables on the occurrence of autumn pollination. The results indicated that the combined effect of three predicting variables, September rainfall, the length of the spring pollen season, and the end of the spring pollen season, explained 92% of the variance. The validation showed a strong relationship between the expected and the observed autumn pollen concentrations. Therefore, the present analysis of a long-term pollen database revealed that the main causes of this unusual second flowering in autumn were strongly related to climate change, i.e., strong dry summers and warm autumns. In addition, the results showed that the phenomenon was more frequent in the years with low pollination during spring due to different meteorological events potentiated by climate change, such as dryness or heavy rain episodes, as a way of ensuring acorn crops. The results explain how this unusual and lesser-known phenomenon in agroforestry dynamics is related to the adaptation to climate change and the main factors that are driving it, as well as the potential consequences for these important and endangered Mediterranean ecosystems

    Diatoms in Forensic Analysis

    Get PDF
    Diatoms are single-celled organisms widely distributed in aquatic environments with several applications, such as oil exploration, environmental indications, microbial ecology or forensic examinations. In this chapter, we address forensic applications of diatom analysis, including the usefulness of the test in the diagnosis of drowning, identification of the drowning site, identification of the suspect and information about the time of death. We also address the sample preparation process and review the most used techniques for diatom analysis involving the digestion of tissues from specific organs to study (acid digestion, acid digestion in disorganization can, Soluene-350 digestion, enzymatic digestion, membrane filter methods and some novel techniques). Finally, we address some protocols in diatom analysis and histological findings in drowning

    Comparison between Airborne Pollen and Aeroallergen Quantification with the ChemVol Impact Sampler. Olive pollen vs Ole e 1

    Get PDF
    Comparison between Airborne Pollen and Aeroallergen Quantification with the ChemVol Impact Sampler. Olive pollen vs Ole e 1. Torres M.C.1, C. Antunes2, M.J. Velasco1, R. Ferro2, H. García-Mozo1, R. Ribeiro2, R.Brandao3, Galán, C1 and the HIALINE team4 1Department of Botany, Ecology and Plant Physiology, University of Córdoba 2Department of Chemistry, University of Évora, Portugal 3Department of Biology, University of Évora, Portugal 4J.T.M. Buters, Germany, M. Thibaudon, France, M. Smith, Great Britain, C. Galan, Spain, R. Brandao and C. Antunes, Portugal, G. Reese, Germany, R. Albertini, Italy, L. Grewling, Poland, A. Rantio-Lehtimäki, Finland, S. Jäger and U. Berger, Austria, I. Sauliene, Lithuania, L. Cecchi, Italy Nowadays, pollinosis is affecting a large percentage of population in the countries with a western life style. The existence of allergenic activity in the atmosphere is not only associated to pollen grains and fungal spores, but also to submicronic and paucimicronic biological particles. The origin of these allergens can be due to the rupture of pollen transported in the atmosphere or to the presence of allergens from other parts of the plant making amorphous material with an allergen load. Olive pollen is recognized as one of the main causes of allergic disease in the Mediterranean area. In this study we have tried to compare olive pollen count in the air and Ole e 1 as major allergen of this species, at two different localities in South of Europe: Evora (Portugal) and Córdoba (Spain). At each location both samplers were placed side-by-side. Pollen grains have been sampled using a volumetric Hirst type spore trap. Chemvol high-volume cascade impactor equipped with stages PM>10µm, 10 µm>PM>2.5µm were used for detecting aeroallergens. Ole e 1 major allergen was determined using allergen specific ELISA´s. Similar behaviour between pollen and the total allergenic load was observed during the pollen season. Nevertheless, at some occasions, during the previous and later period of the pollen season, airborne allergenic load was detected in South Spain, due to the contributions from other Oleaceae species. For this reason the use of these two different methodologies allow a better understanding of the allergenic load in the atmosphere. This work was supported in part by the European Agency for Health and Consumers EAHC, Luxembourg, under the grant agreement 20081107

    Atmospheric Pathways and Distance Range Analysis of Castanea Pollen Transport in Southern Spain

    Get PDF
    The sweet chestnut (Castanea sativa Mill.) is the only native species of this genus in Europe, where it faces various threats that are causing a severe decrease in populations, with the resulting loss of genetic diversity. In the Iberian Peninsula, it is of high economic and ecological importance, being well represented, especially in northern areas, whilst it is limited to isolated populations in medium-range mountains in southern Spain (Andalusia region). Taking advantage of this fragmented distribution, this study analyzes the dynamics of atmospheric transport of Castanea pollen through Andalusia region in order to obtain a better understanding of the pollination pathways as a key aspect of the floral biology of this partially anemophilous species. The aerobiological characteristics of this species are also of special interest since its pollen has been recognized as allergenic. Pollen transport pathways were studied by applying back-trajectories analysis together with aerobiological, phenological, land cover, and meteorological data. The results reveal that airborne Castanea pollen concentrations recorded in the city of Cordoba, in the center of Andalusia region, reach medium- and even long-range distances. The backward-trajectory analysis indicates that most of the pollen data detected outside the Castanea flowering season were related to westerly slow and easterly airflows. Furthermore, some of the case studies analyzed indicate the presence of southerly airflow patterns, which could influence medium- and long-range transport events from chestnut populations further south, even from those located in north African mountains. The integrated analysis of the results offers us better knowledge of the cross-pollination pathways of this endangered species, which help us to understand its genetic flows, as a basis for designing conservation strategies for this highly fragmented species in southern Spain

    Pollen spectrum and risk of pollen allergy in central Spain

    Get PDF
    The present work analyses the airborne pollen dynamic of the atmosphere of Toledo (central Spain), a World Heritage Site and an important tourist city receiving over 2 millions of visitors every year. The airborne pollen spectrum, the annual dynamics of the most important taxa, the infl uence of meteorological variables and the risk of suffering pollen allergy are analysed. Results of the present work are compared to those obtained by similar studies in nearby regions. The average annual Pollen Index is 44,632 grains, where 70–90% is recorded during February–May. The pollen calendar includes 29 pollen types, in order of importance; Cupressaceae (23.3% of the total amount of pollen grains), Quercus (21.2%), and Poaceae and Olea (11.5 and 11.2%, respectively), are the main pollen producer taxa. From an allergological viewpoint, Toledo is a high-risk locality for the residents and tourist who visit the area, with a great number of days exceeding the allergy thresholds proposed by the Spanish Aerobiological Network (REA). The types triggering most allergic processes in Toledo citizens and tourists are Cupressaceae, Platanus, Olea, Poaceae, Urticaceae and Chenopodiaceae-Amaranthaceae. Allergic risk increases in 3 main periods: winter (January–March), with the main presence of the Cupressaceae type; spring, characterized by Poaceae, Olea, Platanus and Urticaceae pollen types; and, fi nally, late summer (August–September), characterized by Chenopodiaceae- Amaranthaceae pollen type, which are the main cause of allergies during these months
    corecore