Abstract
Abstract. Plants disperse spores, pollen, and fragments into the atmosphere. The emitted plant particles return to the pedosphere by sedimentation (dry deposition) and/or by precipitation (wet deposition) and constitute part of the global cycle of substances. However, little is known regarding the taxonomic diversities and flux densities of plant particles deposited from the atmosphere. Here, plant assemblages were examined in atmospheric deposits collected in Seoul in South Korea. A custom-made automatic sampler was used to collect dry and wet deposition samples for which plant assemblages and quantities were determined using high-throughput sequencing and quantitative polymerase chain reaction (PCR) with universal plant-specific primers targeting the internal transcribed spacer 2 (ITS2) region. Dry deposition was dominant for atmospheric deposition of plant particles (87 %). The remaining 13 % was deposited by precipitation, i.e., wet deposition, via rainout (in-cloud scavenging) and/or washout (below-cloud scavenging). Plant assemblage structures did not differ significantly between dry and wet deposition, indicating a possibility that washout, which is possibly taxon-independent, predominated rainout, which is possibly taxon-dependent, for wet deposition of atmospheric plant particles. A small number of plant genera were detected only in wet deposition, indicating that they might be specifically involved in precipitation through acting as nucleation sites in the atmosphere. Future interannual monitoring will control for the seasonality of atmospheric plant assemblages observed at our sampling site. Future global monitoring is also proposed to investigate geographical differences and investigate whether endemic species are involved in plant-mediated bioprecipitation in regional ecological systems.
Highlights
374 000 plant species have been identified worldwide (Christenhusz and Byng, 2016), many of which release spores, pollen, and plant fragments into the global atmosphere
Large particles such as pollen grains serve as giant cloud condensation nuclei (CCN) (GCCN) that can efficiently collide and scavenge smaller droplets when settling from the atmosphere (Johnson, 1982; Möhler et al, 2007; Pope, 2010)
The three most dominant classes or clades found in air samples were Pinidae, rosids, and asterids (Fig. 1a), with respective annual mean concentrations of 117 400, 8600, and 6400 copy numbers (CNs) m−3 based on the number of internal transcribed spacer 2 (ITS2) copies
Summary
374 000 plant species have been identified worldwide (Christenhusz and Byng, 2016), many of which release spores, pollen, and plant fragments into the global atmosphere. Pollen grains are large in size (10–100 μm) compared with other biological particles such as viruses (0.02–0.3 μm), bacteria (0.3–10 μm), or fungal spores (0.5–30 μm) (Hinds, 1999; Jacobson and Morris, 1976). Pollen grains are more influenced by gravity than smaller particles and tend to settle rapidly (Aylor, 2002; DiGiovanni et al, 1995). Large particles such as pollen grains serve as giant CCN (GCCN) that can efficiently collide and scavenge smaller droplets when settling from the atmosphere (Johnson, 1982; Möhler et al, 2007; Pope, 2010).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
