What's in the air? Preliminary analyses of Hawaiian airborne algae and land plant spores reveal a diverse and abundant flora

The airborne algae of Oahu, Hawaii was studied along a transect crossing from the leeward to the windward side of the Koolau Mountain Range in summer 2013. Algae were collected on agarized medium in petri dishes from a car window as the vehicle drove from Honolulu to Kailua, Oahu, through an elevation gradient of > 360 m and a rainfall gradient of c. 900-3150 mm yr(-1). Light microscopy and molecular methods [18S ribosomal (r) RNA gene, 16S rRNA gene, and UPA sequences] were used to characterize a total of 97 operational taxonomic units from the transect. The airborne algal flora of the transect was dominated by cyanobacteria, followed by chlorophycean green algae, diatoms, and ferns and liverworts. This study is the first in Hawaii to incorporate molecular techniques into the identification of airborne algae.