AMOUNT, COMPOSITION AND SEASONALITY OF TERRESTRIAL LITTER ACCESSION TO AN AUSTRALIAN COOL TEMPERATE RAIN-FOREST STREAM

Terrestrial litter accession to a second order Australian cool tempera te rainforest stream was measured over a 15 month period. Total litter accession was a low 310 g m-2 yr-1, with leaves, predominantly of Ath erosperma moschatum and Eucalyptus spp., comprising 56.3 % of the tota l. Green leaves were estimated to make up 19.9 % of the annual leaf fa ll. Litterfall was seasonal with a summer peak, as is usual in Austral ia, and with a secondary winter peak probably associated with snow fal l. In this study, as in other temperate Australian litterfall studies, the annual pattern of litterfall is markedly less seasonal than in No rthern Hemisphere deciduous forests, with 18 % of the annual total ent ering the stream in winter, the season of least litterfall, compared w ith about 5 % of the annual load entering Northern Hemisphere deciduou s forest streams in winter. In addition green leaves formed a very hig h proportion (87 %) of the winter leaf fall. The reduced seasonality o f stream litter accession, and the high quality of the litter in the s eason of minimal accession, in Southern Hemisphere evergreen temperate forest streams may permit the less seasonal, poorly synchronized life histories which appear to be widespread amongst Southern Hemisphere s tream invertebrates.