Airborne Pollen Concentration in Nanjing, Eastern China, and its Relationship With Meteorological Factors

Abstract

This paper presents the results of airborne pollen and spore trapping in Nanjing city, eastern China, using a Burkard pollen trap during two consecutive years (2013)(2014). A total of 103 pollen and spore taxa were identified. Two concentration peaks are observed in the annual cycle, a spring peak dominated by arboreal pollen types (Morus, Cupressaceae, Pinus, Pterocarya, and Quercus) and a fall peak dominated by upland herbs (Compositae, Poaceae, Humulus, and Cruciferae). Wetland herbs and ferns dominate summer assemblages and winter assemblages are characterized by sporadic records of Artemisia, Chenopodiaceae, and Pinus. Strong year-to-year differences in measured pollen concentration are seen, probably in response to interyear differences in weather. Compared to long-term means, 2013 was comparatively hot and dry and 2014 had a higher than average number of rain days during the flowering periods. Rising temperatures in early spring are connected with the timing of flowering and therefore pollen release, while rainfall during the flowering period appeared to remove pollen from the air, leading to lower recorded pollen concentration values. Four taxa, Cupressaceae, Quercus, Pinus, and Humulus, were considered in more detail. Each has a different pattern of variation in pollen concentration between the studied years. Cross correlation between pollen concentration and daily temperature, relative humidity, and precipitation at lags from 0 to À30 days also showed different responses for each taxon, suggesting that pollen signal responses to weather conditions have to be considered at a taxon level rather than at the assemblage level.FANG ET AL.

Phenology and Climatic Regime Inferred from Airborne Pollen on the Northern Slope of the Qomolangma (Everest) Region

“…Although 3 years is not sufficiently long to discuss flowering phenology variations, trends can still be found. The seasonal variation pattern in airborne pollen at QOMS is similar to those in other regions (Fang et al., 2018; Galán, 2016), but differences still exist. The major herb pollen in the study area occur earlier and reach their peak values soon, and the flowering duration lasts for a shorter time.…”

“…The major herb pollen in the study area occur earlier and reach their peak values soon, and the flowering duration lasts for a shorter time. However, in inland cities in China, such as Beijing and Nanjing, herb pollen starts in August and can last until October (Fang et al., 2018; Xu et al., 2012). Plant phenology monitoring also reveals early flowering and short flowering duration in alpine regions because of low air temperature, reflecting adaptation to high elevations and cold climates (Lü et al., 2009; Zhou, 2001).…”

“…In addition, airborne pollen can also help to better understand fossil pollen records as a tool to reconstruct palaeoenvironments (Zhu et al., 2015). However, most airborne pollen studies in China have been conducted in inland or urban areas (Fang et al., 2018; Li et al., 2015), and very few have been performed in remote areas, such as the TP (Cour et al., 1999; Lu et al., 2010).…”

Relationship between airborne pollen assemblages and major meteorological parameters in Zhanjiang, South China

“…However, as previous studies have indicated [ 20 – 22 ], the interpretation of the results of correlation analysis between pollen concentrations and meteorological parameters is difficult because time series of pollen concentrations represent a strongly non-stationary and non-ergodic process, or because the relationship between pollen and meteorological conditions may be nonlinear, depending on the simultaneous effects of several meteorological parameters [ 23 ]. The relationship between airborne pollen and meteorological parameters has been extensively investigated worldwide, such as in urban areas in China [ 24 ], India [ 25 ], and Canada [ 26 ], et al [ 27 ]. However, few studies have been conducted in the southern subtropical monsoon zone; moreover, there are very few studies of the impact of severe weather events (i.e.…”

Hygroscopic Properties of 11 Pollen Species in China

“…To our knowledge, all previous studies were focused on hygroscopicity of pollen species mainly found in North America and Europe, and hygroscopic properties of pollen species in China remain to be understood. Abundant pollen aerosols were found in ambient air in China, with higher concentrations observed in spring and autumn. , In the present work, we investigated hygroscopic properties of 11 pollen species from representative plants in China up to 90% RH (and even up to 95% RH for some pollen species). Experiments were also carried out at 37 °C (i.e., the physiological temperature) in addition to 25 °C, to help us better understand the transport and deposition of pollen in the respiratory tract.…”