Daily variations of airborne pollen in Beijing Olympic Park during August of three consecutive years and their relationships with meteorological factors

A three-year aeropalynological study was carried out in the month of August for each of the three years 2005, 2006 and 2007 in the Beijing Olympic Park. A total of 19550 pollen grains were counted （15057 grains in 2005, 2717 in 2006 and 1776 in 2007） for the following taxa： Gramineae, Chenopodiaceae, Humulus L., Artemisia L., Ambrosia L. and Pinus L. The analysis indicated that in the three consecutive years of 2005-007, airborne pollen types and daily number of pollen in August in the Beijing Olympic Park were closely related to environmental change and vegetation composition. The daily variations of airborne pollen displayed similar patterns in August in each of the three years, which were affected positively by periods of daily sunshine, negatively by daily relative humidity and daily precipitation. Continuously high daily temperatures and stable daily wind speeds seemed to have little effect on the fluctuation of airborne pollen.

The study of airborne pollen and spores inTaoyuan, Hunan Province of China

In order to study the airborne pollen and Spores, a circular year airborne Samples werecollected at 10m height above ground from Taoyuan ecological station, which is located in TaoyuanCounty of Hunan Province. The analytical results showed that there are 188 plant families and generain airborne pollen and spores. of them, 102 are xylophyte plants, 68 are herbase plat, and 18are pteridophyta plants. The plant families and genera account for 80% of the local plant families andgenera. Among them, 54 are specific families and genera, Which are peculiar tO tropics andsubtropics. The main pollen and spore families and genera are Pinus. Cunninghamia Juglans,Quercus, Cupressaceae, Urticaceac, and Gleicheniaceae. There are two peak stages of airbornepollen and spore concentration throughout the year. One is the peak stage of xylophyte plants fromMarch to May and the other, herbaceous plants from niddle dekad of August to early October. Themaximum year round value is 850 000 grains/1000m3.air in middle dekad of September and theminimum is 1500 grains/1000m3.air in early December. In the local district, the airbome pollen andSpores which can induce respiratory tract disease in spring are Taxodiaceae, Cupresaseeae, CastrieaCastanopsis, Queme, Juglans, Platycarya, and that can induce disease in autumn are Canabis,Gramineae, and Artmisia.

Airborne pollen patterns and their relationship with meteorological factors in the Betula microphylla-dominated wetland of Ebinur Lake,Xinjiang,China

Airborne pollen is indicative of vegetation and climatic conditions.This study investigates airborne pollen trapping in the Betula microphylla-dominated wetland of Ebinur Lake in Northwestern China from September 2012 to August 2015 using Pearson correlation analysis and the Hybrid Single-particle Lagrangian Integrated Trajectory model.Higher temperatures and moderate precipitation during the flowering period facilitated an increase in birch pollen with more exotic spruce pollen carried from the Tianshan Mountains by airflows,leading to the highest arbor pollen concentrations from September 2012 to August 2013.Peak pollen concentrations from September 2013 to August 2014 were possibly due to an increase in herbaceous pollen resulting from higher temperatures,lower precipitation and more exotic pollen from the desert of southwest Ebinur Lake and Central Asia in summer and autumn.Between September 2014 and August 2015,unfavorable climate conditions in summer and autumn decreased the pollen dispersal of xerophytes such as Artemisia and Chenopodiaceae,with little pollen transported from the Kazakh hilly area in late summer,resulting in the lowest pollen concentrations.Climatic parameters and air mass movements both greatly affected the atmospheric pollen concentration.The results provide information concerning the dispersion and distribution of birch pollen,paleoenvironmental reconstruction and wetland conservation.