This study aims primarily to assess the response of two invertebrate groups to the effects of pastoralism and military training, at one site in the tropical savanna of north-eastern Queensland. The richness and species composition of ants and terrestrial spiders were examined at two contrasting times of year across three land use treatments (pastoralism, military training and undisturbed) and four landscape positions (upper slope to riparian). Ant species richness was least in the grazed sites, and a high proportion of the ant species recorded varied significantly in frequency between the grazed and the two ungrazed land uses. This variation was generally greater than that associated with landscape position. Although variation in the richness of spiders was significantly related to land-use type, this effect was less pronounced than for ants, was less marked than variation associated with landscape position and was confounded by a strong interaction between land use and landscape position. Quadratscale variation in the composition of spider assemblages was influenced most by season of sampling. For both spiders and ants, there were few differences in richness or species composition between undisturbed land and that managed for military use.

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The millipede by-catch from a 1986-88 spider survey in Tasmanian coastal heathland was tallied by species, sex and life-stage. Two species of paradoxosomatid Polydesmida, Notodesmus scotius Chamberlin, 1920 and Pogonosternum sp., made up 99.8% of the pitfall captures. The N. scotius catch (9754 individuals) was 80% adult (stadium VIII) and peaked in October-December with only 23 captures in July-September. The Pogonosternum sp. catch (116 individuals) was 91% adult and peaked in September, with 40% of all captures in July-September. These results, together with field observations, indicate that pitfall trapping mainly captured adults wandering during the mating season, and that mating seasons for the two species did not coincide. The Pogonosternum sp. captures were tightly clustered in space, showing that pitfall trapping can be an unreliable method for estimating millipede abundance unless the fine-scale spatial patterning of target species is known in advance. A third paradoxosomatid species known to be present near the survey sites, Dicranogonus sp., did not appear in any of the 938 pitfall samples containing millipedes. The overwhelming dominance of paradoxosomatid Polydesmida in heathland is in marked contrast to the dominance of dalodesmid Polydesmida in forest habitats in Tasmania.

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