10 research outputs found

    Sedimentological and ichnological implications of rapid Holocene flooding of a gently sloping mud-dominated incised valley – an example from the Red River (Gulf of Tonkin)

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    The Gulf of Tonkin coastline migrated at an average rate of ca 60 m year−1 landward during Holocene sea-level rise (20 to 8 ka). Due to a combination of rapid coastline migration and undersupply of sand, neither coastal barriers nor tidal sand bars developed at the mouth of the Red River incised valley. Only a 30 to 80 cm thick sandy interval formed at the base of full-marine deposits. Thus, the river mouth represented a mud-dominated open funnel-shaped estuary during transgression. At the base of the valley fill, a thin fluvial lag deposit marks a period of lowered sea-level when the river did not reach geomorphic equilibrium and was thus prone to erosion. The onset of base-level rise is documented by non-bioturbated to sparsely bioturbated mud that occasionally contains pyrite indicating short-term seawater incursions. Siderite in overlying deposits points to low-salinity estuarine conditions. The open funnel-shaped river mouth favoured upstream incursion of seawater that varied inversely to the seasonal strongly fluctuating discharge: several centimetres to a few tens of centimetres thick intervals showing marine or freshwater dominance alternate, as indicated by bioturbational and physical sedimentary structures, and by the presence of Fe sulphides or siderite, respectively. Recurrent short-term seawater incursions stressed the burrowing fauna. The degree of bioturbation increases upward corresponding to increasing marine influence. The uppermost estuarine sediments are completely bioturbated. The estuarine deposits aggraded on average rapidly, up to several metres kyr−1. Siphonichnidal burrows produced by bivalves, however, document recurrent episodes of enhanced deposition (>0·5 m) and pronounced erosion (<1 m) that are otherwise not recorded. The slope of the incised valley affected the sedimentary facies. In steep valley segments, the marine transgressive surface (equivalent to the onset of full-marine conditions) is accentuated by the Glossifungites ichnofacies, whereas in gently sloped valley segments the marine transgressive surface is gradational and bioturbated. Marine deposits are completely bioturbated

    Yew and juniper pollen season in selected cities of Poland in 2020

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    The study compares the yew and juniper pollen seasons in Bialystok, Bydgoszcz, Cracow, Lublin, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, and Wroclaw in 2020. The investigations were conducted using the volumetric method. The yew and juniper season started in all measurement sites between February 2nd (Szczecin) and March 2nd (Lublin). The peak values of seasonal pollen count occurred between February 23rd (in Szczecin) and March 28th. The highest daily pollen count was recorded in Lublin (867 grains/m3) and the lowest pollen count in Bialystok (45 grains/m3). The highest annual totals were recorded in Lublin and Wroclaw. Most days, with a concentration equal to or above 50 grains/m3, causing symptoms in allergic patients were recorded in Lublin and Warsaw

    Analysis of the plantain pollen season in selected Polish cities in 2018

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    The paper presents the course of pollen season of plantain in Bialystok, Bydgoszcz, Drawsko Pomorskie, Cracow, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora in 2018. Measurements were performed by the volumetric method (Burkard and Lanzoni pollen samplers). Pollen season was defined as the period in which 98% of the annual total catch occurred. The plantain pollen season started in the first decade of May and lasted until the end of September. Despite such a long pollen season in Poland, only in some cities there are days with an average concentration exceeding 10 P/m3. Significant differences were observed in annual sum values. The highest values were recorded in Lublin (400 grains) and Zielona Gora (308 grains), and the lowest in Drawsko Pomorskie (160 grains) and Olsztyn (184 grains). The value of annual average in 2018 was usually lower than in the previous years

    Ambrosia pollen season in selected cities in Poland in 2018

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    Ambrosia causes most pollen allergies in North America. After several Ambrosia species were introduced to Europe, an increase in the incidence of allergy to pollen of these plants has been observed in many countries. The aim of this study was to compare Ambrosia pollen seasons in 2018 in 13 cities located in different regions of Poland: Bialystok, Bydgoszcz, Cracow, Drawsko Pomorskie, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora. The study was conducted by the volumetric method using Burkard or Lanzoni pollen samplers. The pollen season was determined by the 98% method. The earliest pollen season start dates (the end of July) were recorded in Zielona Gora, Bydgoszcz, Opole and Szczecin, while the latest ones in Drawsko Pomorskie and Bialystok. The longest pollen seasons occurred in Opole, Szczecin and Zielona Gora (79 days). The highest average daily concentrations of Ambrosia pollen were recorded in Bialystok (129 P/m3) and Lublin (99 P/m3), while the lowest ones in Drawsko Pomorskie and Szczecin (4 and 10 P/m3, respectively). The annual pollen sum reached the highest value in Opole (567 pollen grains) and Zielona Gora (555 pollen grains). It can be concluded from the pattern of Ambrosia pollen seasons at the monitoring sites studied that pollen of this taxon originates not only from Ambrosia locations in Poland but also from long-distance transport

    Analysis of mugwort (Artemisia) pollen seasons in selected cities in Poland in 2018

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    The aim of the present study was to compare the mugwort pollen season in 2018 in Bialystok, Bydgoszcz, Cracow, Drawsko-Pomorskie, Lublin, Olsztyn, Opole, Sosnowiec, Szczecin, Warsaw, Wroclaw, and Zielona Gora. Pollen concentration measurements were made by the volumetric method using Burkard or Lanzoni pollen samplers. The pollen season was considered as the period during which 98% of the total annual pollen count occurred. The Seasonal Pollen Index (SPI) was calculated as the sum of the average daily pollen concentrations throughout the season determined for the individual cities. The mugwort pollen season started earliest in Bialystok (June 21st) and Bydgoszcz (June 25th), while in the other cities its onset occurred in the first 10 days of July. Significant differences were found in season duration (68–110 days), SPI, and peak value. The longest season occurred in Zielona Gora and Bydgoszcz, while the shortest one in Wroclaw. The highest SPI and maximum concentration values were observed in Lublin and Zielona Gora. In most of the cities, the peak value was recorded in the first 10 days of August. The highest risk of allergy in people sensitive to the pollen of this taxon was found in Zielona Gora, Lublin, and Warsaw

    Comparison of Artemisia L. pollen concentrations and risk of development of allergy symptoms in different regions of Poland in 2020

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    In Central Europe, mugwort pollen is a frequent cause of pollen allergy. Poland is one of the countries with the highest airborne concentrations of pollen of this taxon. Due to its high allergenic potential, Artemisia pollen may pose a significant threat to sensitive subjects during summer months. Plants from this genus often grow in urban and suburban areas. The aim of the study was to compare mugwort pollen seasons and concentrations of airborne pollen of these plants in 12 cities located in different regions of Poland: Bialystok, Bydgoszcz, Cracow, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw, and Zielona Gora. The investigations were carried out with the volumetric method using a Hirst-type pollen sampler (Lanzoni or Burkard) operating on a 24-hour basis. The duration of the pollen season was determined with the 98% method. The earliest onset of the mugwort pollen season was noted in Opole (July 12th), and the latest beginning was recorded in Cracow and Sosnowiec (July 23th). The maximum pollen concentrations were reported on August 7th and 8th in Lublin (177 grains/m3) and Wroclaw (100 grains/m3). In all the cities, peak days were recorded on the first 10 days of August. The maximum pollen concentrations in the other cities were in the range of 18–89 grains/m3. The highest annual pollen sum was recorded in Lublin (1423) and Wroclaw (1050). These values coincided with the highest pollen concentrations determined in these cities. The annual Artemisia pollen sums in 2020 did not have the highest values in comparison with other years in these cities. The average annual pollen sum in the five-year period of 2001–2005 was estimated at 2065 in Lublin and 1662 in Wroclaw. Therefore, it can be concluded that the risk of mugwort pollen allergy in the pollen season 2020 was lower than in some previous years

    Analysis of Fraxinus pollen seasons in selected cities of Poland in 2018

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    The study compares the ash pollen seasons in Szczecin, Drawsko Pomorskie, Bydgoszcz, Zielona Gora, Wroclaw, Opole, Sosnowiec, Cracow, Piotrkow Trybunalski, Warsaw, Lublin, Olsztyn and Bialystok in 2018. The investigations were carried out using the volumetric method. The ash pollen season began between April 7th and April 10th. Maximum daily pollen concentrations were noted earliest on April 10th and latest on April 17th. The greatest risk of allergies caused by the presence of airborne ash pollen was observed in Lublin

    1. Wochenbericht L17-20

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    Wochenbericht Li17_20 (20.11. – 26.11.2017
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