Flora and fauna assemblages vary with local topography in a subtropical eucalypt forest

Local-scale spatial patterning (over hundreds of metres) in terrestrial ass emblages was investigated by sampling a variety of organisms within a 400 h a eucalypt forest area in the lowlands of south-east Queensland. Organisms were trees, shrubs, birds, insects extracted from the litter layer, and ins ects caught in pitfall traps. Each group was sampled using a standardized m ethodology, and the component taxa were counted and identified to a level c ommonly used in ecological studies of that organism - varying from species to order levels. Sites adjacent to drainage lines or ephemeral streams were biotically more similar to one another than they were to paired upslope si tes 100-200 m distant and 15-35 m higher in altitude. This phenomenon occur red irrespective of the level of taxonomic resolution or type of organism. Within each taxonomic group, some components were mainly riparian, while ot hers were more characteristic of upslope sites. Characteristically riparian taxa included trees in the genus Glochidion, the shrub genus Leptospermum, birds in the Pachycephalidae and Meliphagidae families, and litter inverte brates in the order Acarina. Upslope taxa included shrubs in the Rutaceae, birds in the Artamidae, and ants. Within the groups of trees, birds and lit ter invertebrates, more taxa were characteristic of riparian than upslope s ites. Local scale biotic patterns were more strongly correlated with altitu de than with measured soil characteristics; however, microtopographical dif ferences would also be highly correlated with a large suite of covarying en vironmental features. The patterns of diversity and the implications for su rvey design and conservation are discussed.