Abstract
Variations in the foam spora of a stream in a lowland tropical forest in Singapore were monitored over 5 months. Spore concentration in foam samples varied from a low 52 (+/- 5) spores ml(-1) to 621 (+/- 74) spores ml(-1). High counts were associated with periods of rainfall. The dominant spore forms were Beltrania rhombica, Triscelophorus acuminatus, Trichocladium cylindroclavatum, Ingoldiella hamata and Trichocladium singaporense. Variations in spore load and relative abundance of species were attributed to terrestrial run-off, increased stream flow and abundance of foam formed during the wet months, rather than to changes in the physico-chemical conditions of the stream. The abundance of B. rhombica in foam samples and on submerged decaying leaves indicated that it could be adapted to an aquatic form of life, and constituted a dominant 'resident' species in the mycoflora of the stream.