Phylloplane bacteria in a pine forest

Abstract

Fluctuation of bacterial population occurring in the three growth stages (young, old, and decaying) of the leaves of Pinus densiflora and in the air of the same pine forest was examined using the dilution plate method. The total count of bacteria isolates from the phylloplanes of pine was not high but seasonal fluctuations, particularly with respect to composition, were marked bacterial populations. Approximately 70% of the total isolates collected in 5 years was found to belong to the following four groups: pink chromogens, Bacillus, Flavobacterium, and coryneform bacteria. Among them, pink chromogens occurred abundantly on the living phylloplanes of P. densiflora during summer. Bacillus was isolated from the various sources all year round. Coryneform bacteria occurred in the air of the pine forest throughout the year. Flavobacterium was observed in all sources, but not in high number. Staphylococcus and Micrococcus were not detected on the phylloplanes in spite of their abundance in the air.