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

Yiman Fang,Chunmei Ma,Huayu Lu,M Jane Bunting,Aijun Ding,Wenfeng Sun

doi:10.1029/2018jd029026

Abstract

AbstractThis 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 −30 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.

Highlights

This paper presents the results of airborne pollen and spore trapping in Nanjing city, eastern
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)
Aeropalynology trapping programs provide a large amount of data on patterns of airborne pollen both within and between years and have enabled the development of models for short-term forecasting of pollen counts and allergy risk

Summary

Introduction

Aeropalynology trapping programs provide a large amount of data on patterns of airborne pollen both within and between years and have enabled the development of models for short-term forecasting of pollen counts and allergy risk. Nanjing is a large city in eastern China (Figure 1), but the only available pollen trapping data cover subannual time periods and report the main airborne pollen types during peak seasons (e.g., Wei et al, 2008; Zhang et al, 2009). In these situations, even 1- to 2-year monitoring sequences can provide useful new insights into the annual pattern of airborne pollen and relationships between meteorological conditions and the abundance of the main pollen types

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Conclusion