Saproxylic insects comprise a diverse, species-rich and dominant functional group that share a dependence on dead wood and the old trees that generate it (mature timber habitat). Recent research has highlighted their sensitivity to forest management, with managed or secondary forests generally supporting fewer individuals, fewer species, and different assemblages compared to old-growth or primary forests. This sensitivity is a product of their association with a habitat that tends to diminish in managed forests. Many species also have low powers of dispersal relative to human-induced fragmentation, making breaks in habitat continuity particularly harmful. In western Europe, many species are now regionally extinct. Information is largely lacking elsewhere, but similar ecological and management principles should apply. Measures taken to protect the habitat of hollow-dependent vertebrates may ensure the survival of some saproxylic insects, but unless their needs are expressly considered, there remains the risk that many others may be lost as forest areas shrink and management of remaining areas intensifies.

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Tropical Cyclone ‘Rona’ crossed the coast of the Daintree lowlands of northeastern Australia in 1999. This study reports on its impact on forest canopy openness at six lowland rain forest sites with contrasting management histories (old-growth, selectively logged and regrowth). Percentage canopy openness was calculated from individual hemispherical photographs taken from marked points below the forest canopy at nine plots per site 3–4 mo before the cyclone, and at the same points a month afterwards. Before the cyclone, when nine sites were visited, canopy openness in old-growth and logged sites was similar, but significantly higher in regrowth forest. After the cyclone, all six revisited sites showed an increase in canopy openness, but the increase was very patchy amongst plots and sites and varied from insignificant to severe. The most severely impacted site was an old-growth one, the least impacted a logged one. Although proneness to impact was apparently related to forest management history (old-growth being the most impacted), underlying local topography may have had an equally strong influence in this case. It was concluded that the likelihood of severe impact may be determined at the landscape-scale by the interaction of anthropogenic with meteorological, physiographic and biotic factors. In the long term, such interactions may caution against pursuing forest management in cyclone-prone areas.

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The results of a beach seine survey of an East African mangrove creek are presented. The fish community of the creek is described and is compared with that of a nearby lagoonal site and with those described for other mangrove and estuarine systems. The species composition was found to differ substantially between thecreek and the lagoon site, though diversity indices for the two arcas weresimilar. Eighty-threespeciesofteleost fish werecollected from themangrovearea ofthecreek. This number is considered high in relation to comparable studies and is attributed to the constant high salinity (approximately 350/00) measured throughout the study period. Approximately 90% of the fish caught were juveniles. Plankton sampling was also carried out and representatives of21 fish families were collected as larvae within the creek. Catches from both beach seining and plankton sampling in the mangrove areas were dominated numerically by resident clupeid and gobiid species. The majority of species, however. were considered to have a widespread distribution a s adults. A discrepancy between the catch composition of larvae and juveniles suggests that species that use the creek as a nursery area enter the system principally at a post-larval/ juvenile stage of development. No systematic spatial or temporal variation in the community structure was identified over the study period.

In this paper we consider the extent of our knowledge of global beetle diversity. Depending on the estimates adopted, some 70–95% of all beetle species remain to be formally described, and at the current rate of progress it could be more than 200 years until the task is completed. One of the reasons for this is the difficulty of adequately sampling tropical beetle faunas and thereby ensuring sufficient material is available to taxonomists for comparative studies. Despite this, recent years have seen significant advances in our understanding of beetle taxonomy, biology, ecology and biogeography, and we are now in a good position to apply this understanding to ecological and management issues. Saproxylic (dead-wood-associated) beetles are used to illustrate this latter point.