Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 7497-7506, 2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
16 Jun 2016
Fungal spores overwhelm biogenic organic aerosols in a midlatitudinal forest
Chunmao Zhu1,2,a, Kimitaka Kawamura1,b, Yasuro Fukuda1,3, Michihiro Mochida4,c, and Yoko Iwamoto4,d 1Institute of Low Temperature Science, Hokkaido University, Sapporo 0600819, Japan
2CMA Key Laboratory of Aerosol-Cloud-Precipitation, Nanjing University of Information Science and Technology, Nanjing 210044, China
3Graduate School of Environmental Science, Hokkaido University, Sapporo 0600810, Japan
4Institute of Advanced Research, Nagoya University, Nagoya 4648601, Japan
anow at: Department of Environmental Geochemical Cycle Research, Japan Agency for Marine–Earth Science and Technology, Yokohama 2360001, Japan
bnow at: Chubu Institute for Advanced Studies, Chubu University, Kasugai 4878501, Japan
cnow at: Graduate School of Environmental Studies, Nagoya University, Nagoya 4648601, Japan
dnow at: Faculty of Science Division I, Tokyo University of Science, Tokyo 1628601, Japan
Abstract. Both primary biological aerosol particles (PBAPs) and oxidation products of biogenic volatile organic compounds (BVOCs) contribute significantly to organic aerosols (OAs) in forested regions. However, little is known about their relative importance in diurnal timescales. Here, we report biomarkers of PBAP and secondary organic aerosols (SOAs) for their diurnal variability in a temperate coniferous forest in Wakayama, Japan. Tracers of fungal spores, trehalose, arabitol and mannitol, showed significantly higher levels in nighttime than daytime (p < 0.05), resulting from the nocturnal sporulation under near-saturated relative humidity. On the contrary, BVOC oxidation products showed higher levels in daytime than nighttime, indicating substantial photochemical SOA formation. Using tracer-based methods, we estimated that fungal spores account for 45 % of organic carbon (OC) in nighttime and 22 % in daytime, whereas BVOC oxidation products account for 15 and 19 %, respectively. To our knowledge, we present for the first time highly time-resolved results that fungal spores overwhelmed BVOC oxidation products in contributing to OA especially in nighttime. This study emphasizes the importance of both PBAPs and SOAs in forming forest organic aerosols.

Citation: Zhu, C., Kawamura, K., Fukuda, Y., Mochida, M., and Iwamoto, Y.: Fungal spores overwhelm biogenic organic aerosols in a midlatitudinal forest, Atmos. Chem. Phys., 16, 7497-7506,, 2016.
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Short summary
We collected aerosol samples in a midlatitude forest in Wakayama, Japan and analyzed the organic tracers of various sources. We found that compounds originating from fungal spores contributed significantly to total organic aerosol mass. On the other hand, those from oxidation of biogenic volatile organic compounds, although they could not be ignored, had relatively smaller mass fractions.
We collected aerosol samples in a midlatitude forest in Wakayama, Japan and analyzed the organic...