The termite (Isoptera) fauna of a monsoonal rainforest near Darwin, northern Australia

Abstract

Termite species richness, frequency of occurrence and functional diversity at Holmes Jungle Nature Reserve, a monsoon rainforest patch in northern Australia, was investigated at the end of the wet season in 2003. A sampling protocol that employed direct search, soil pits and baiting techniques was used to sample litter, wood, mound, soil and arboreal nest microhabitats for termites. Five species from five genera and three families (Mastotermitidae, Rhinotermitidae and Termitidae) were recorded. This included the first record of Ephelotermes taylori (Hill) from monsoon forest in Australia. The family Termitidae was dominant and represented 70% of termite occurrences. Termites were most frequently encountered in carton runways on tree trunks, followed by lying dead wood and baits. Four nesting habits were represented: arboreal, epigeal, hypogeal and within wood. The arboreal nestbuilder Nasutitermes graveolus (Hill) accounted for 61% of termite encounters. Epigeal moundbuilding species were rare. Wood-feeders were the only trophic group represented. Relatively high activity of Mastotermes darwiniensis Froggatt was recorded at baits within 2.5 months. The low species richness recorded at Holmes Jungle is consistent with the low diversity reported for Australian rainforests generally, but remains relatively depauperate compared with other monsoon forest and savanna habitats of the Northern Territory.

Abundance and diversity of termites in a savanna woodland reserve in tropical Australia

“…Using the same methodology as the present study, Dawes-Gromadzki (2005a) recorded only five species in a monsoon rainforest reserve located a few kilometres from CDNP. These Australian studies contrast to those from African savannas, where woodland habitats are generally species-poor compared with the species-rich rainforest habitats (Wood 1976;Dibog et al 1999;Dawes-Gromadzki 2005a).…”

“…These data were used to provide an overall indication of termite community structure based on the relative frequency of occurrence of different species and functional groups (Jones 2000;Dawes-Gromadzki 2005a).…”

“…A number of soil characteristics can also influence termite species diversity and abundance (Lee & Wood 1971;Jones & Prasetyo 2002;Dawes-Gromadzki 2005a). Soils with poor drainage capacity or inundation susceptibility can inhibit activity and provide unsuitable conditions for soil-dwelling and mound-building species (Jones 2000;Dawes-Gromadzki 2005a).…”

“…Soils with poor drainage capacity or inundation susceptibility can inhibit activity and provide unsuitable conditions for soil-dwelling and mound-building species (Jones 2000;Dawes-Gromadzki 2005a). In such environments, wood-and arboreal-nesting species are common.…”

“…Despite the recognised importance of termites to ecosystem function in tropical north Australia, there has been little effort devoted to the documentation of termite community inventories (Braithwaite et al 1988;Dawes-Gromadzki 2005a). At a given site the composition of a local termite assemblage will govern the overall impacts of termites on ecosystem processes (Lavelle et al 1997;Jones & Prasetyo 2002).…”