Foraging parameters of two ant species, Pseudomyrmex triplarinus and Crematogaster sp., on P. triplarinus-occupied shrubs of Triplaris surinamensis were evaluated in a semi-deciduous forest of Mato Grosso, western Brazil. Live workers of the termite Microcerotermes strunckii, used as baits for ants, were placed on leaves in the lower, medium and upper thirds of the crown of thirty experimental Triplaris (nine baits/plant). Besides attacking more than twice as many baits as Crematogaster (131 against 59), Pseudomyrmex also attacked them signifi cantly faster. Pseudomyrmex patrolled the plant uniformly, while Crematogaster patrolled more intensively the lower portion of the crown of Triplaris. Baits retrieved by Pseudomyrmex were taken to their nests in the stem galleries of Triplaris; those retrieved by Crematogaster were carried to nearby nests in the forest understory. Greater aggressiveness and alertness to foreign objects (i.e. baits), better eyesight, larger size, and an individual foraging technique appear to be responsible for the greater foraging success of Pseudomyrmex when compared with Crematogaster.

Site data from 291 forest inventory plots in Mixed Dipterocarp Forest in central Sarawak were simplified by factor analysis. The distribution of the 33 commonest canopy tree species was related to site factor scores by ‘t’ tests. There appears to be a degree of edaphic influence on the distribution of many species. Fairly constant soil characteristics related to the lithology of the parent material appear to be more important than ephemerally variable pro perties such as organic matter or exchangeable cations. Magnesium appears to be particularly important, possibly because of an effect on the capacity of mycorrhizal root systems to absorb phosphorus.

To assess the influence of microhabitat and season on predator growth and survival and prey community structure, first instars of native Toxorhynchites haemorrhoidalis, a predatory mosquito, were released into Heliconia bracts, bamboo internodes, and the axils of two species of Aechmea bromeliads during wet and dry seasons in a lowland rain forest in eastern Venezuela. Experimental and control microhabitats were compared by complete censusing of macroscopic invertebrates 10 and 20 days after releases.

Survival of T. haemorrhoidalis differed significantly among habitats and was reduced by desiccation in dry-season bamboos and in Aechmea nudicaulis and by the presence of a predatory damselfly (Odonata: Zygoptera) in bromeliads. Developmental rate differed among habitats in the wet but not in the dry season; rapid wet-season maturation was associated with increased prey abundance in Heliconia.

Larvae of T. haemorrhoidalis consumed particular taxa and size categories of dipterous prey. Predation significantly reduced the abundance and skewed size-class distributions of Culicidae, Ceratopogonidae, Psychodidae, and pooled samples of Thaumaleidae plus Chironomidae. In bamboos, instar distributions of other mosquitoes were skewed in the presence of T. haemorrhoidalis even though a significant reduction in mosquito abundance was not detected. A decrease in species richness of aquatic Diptera was associated with intense predation by Toxorhynchites in Heliconia and A. nudicaulis.

Toxorhynchites theobaldi was recognized as the naturally occurring predator in local bamboos, and released larvae caused significant reductions in abundance or size-class frequency shifts among three families of Diptera. Niche segregation between these sympatric Toxorhynchites is maintained by oviposition preferences: the larger species, T. theobaldi, oviposits in bamboos and the smaller T. haemorrhoidalis occurs in plant bracts and axils.

Stemonoporus Thw. (Dipterocarpaceae), a genus endemic to Sri Lanka, contains as many as 26 species, all but one confined to the perhumid forests of the island. Several species reach 1800 m, the highest altitude recorded for any dipterocarp species in Sri Lanka. We report the first quantitative data on Stemonoporus-domirated stands in the montane zone (1500–1700 m). Stemonoporus cordifolius and 5. rigidus show clear single-species dominance of their respective stands. Stemonoporus gardneri is a co-dominant with Palaquium rubiginosum in its two stands. All Stemonoporus species appear to have a unique geographical and ecological range and no two Stemonoporus species co-exist in our stands.

The contribution of a population of mound building, detritivorous termites (Amitermes laurensis (Mjöberg)) to nett carbon mineralization in an Australian tropical semi-arid woodland has been examined. Carbon mineralization rates were estimated by measuring daily CO2 flux from five termite mounds at monthly intervals for 12 months. Carbon flux from the mounds was found to be due to microbial activity as well as termite activity. It is conservatively estimated that the association of A. laurensis and the microbial population present in their mounds is responsible for between 4%–10% of carbon mineralized in this ecosystem, and the contribution of all termites together (mound builders and subterranean) may account for up to 20% of carbon mineralized. Regression analysis showed that rates of carbon mineralization in termite mounds were significantly related to mound moisture and mound temperature. Soil moisture was the most important factor in soil carbon mineralization, with temperature and a moisture X temperature interaction term also exerting significant affects.

A quantitative analysis of the effect of fire regime on the abundance of common lizard species and genera and the species richness of two lizard groups in Kakadu National Park (12° S) is presented. A surprising range of relationships between species abundance and components of fire regimes was revealed. Carlia amax, Heteronotia binoei and Carlia gracilis appear to be fire-sensitive, Diporiphora bilineata and Carlia triacantha are favoured by early hot fires, Cryptoblepharus plagiocephalus seems relatively unaffected, Carlia foliorum seems very tolerant of fires, while Ctenotus and Sphenomorphus spp. are favoured by low intensity, patchy fires with high intensity spots.

Lizard species experiencing the high-frequency fire regimes of the savannas and dry forests of the Australian wet-dry tropics are not able to select habitat at different stages of regeneration after fire but select habitat produced by fires of different types. The implication for management is that no one fire regime is optimal for the fauna as a whole. A range of fire regimes within a park should be maintained in order to retain the whole fauna.