摘要
The occurrences of 227 vertebrate species recorded on 487 forested sites in north-eastern New South Wales were investigated to determine the levels of association among species, the distribution of species by broad functional groups, species relations with key environmental and disturbance variables, the sensitivity of species to intensive logging, and to list species that have potential value as direct indicators of major environmental change and which should be considered as candidates for long-term monitoring.A total of 40 species appeared to be significantly disadvantaged by logging, another 40 species appeared to be significantly favoured by logging, while the remainder (147 species) appeared to be relatively unaffected. Most species were widely distributed throughout both logged and unlogged landscapes, albeit at possibly quite different abundances. This may be due to the fine-scale complexity of the habitat mosaic for many species, resulting in the continued availability of essential resources within or near logged areas, or the lack of sufficient sensitivity in the analysis due to the need to use presence–absence data. A further 121 species were recorded so rarely in the study (based on 619 sites) that it was not possible to make any assessments of their sensitivity to logging. The study produced several unexpected results, including the failure to identify some species as sensitive to logging that had previously been identified as sensitive in experimental and other retrospective studies.Species disadvantaged by logging were often either dependent on large old trees and/or tree hollows for nesting, roosting and foraging, such as the Common Brushtail Possum, Red-browed Treecreeper, Satin Flycatcher and Crimson Rosella, or they were species that inhabit open forests and woodland, such as the Rufous Bettong, Buff-rumped Thornbill, White-throated Gerygone, White's Skink and Nobbi, that were probably disadvantaged by the increase in stem density and understorey and mid-canopy cover that usually follows logging. In contrast, species favoured by logging, such as the Eastern Whipbird, Brown Gerygone, Lewin's Honeyeater, Wonga Pigeon and Land Mullet, were often those species preferring wetter forest environments, particularly those with multi-layered foliage and a forest structure that includes fallen logs and a dense ground cover. No species displayed consistently strong preferences for selectively logged forest. Mammals were more likely to be disadvantaged by logging than birds, but reptiles contained the largest proportion of species sensitive to logging (39 % ). Frogs were inadequately sampled in this study; only nine species were recorded. While each taxonomic group had some species that were apparently sensitive to logging, the time frame to population recovery following logging disturbance may differ widely between groups depending on their habitat requirements. Fire history was also strongly correlated with the occurrences of many species, indicating the need to quantify species sensitivity to regular fuel-reduction burning.Three main assemblages of species were identified. One group consisted of rainforest or wet forest specialists, another group comprised open-forest generalists, including a number of open-country and woodland species, and a third group was made up of tall, eucalypt forest generalists, including all of the large forest owls and marsupial gliders. Each broad assemblage, and most of their sub-groups, were found to have at least one species that was apparently sensitive to logging. The study was unable to test whether these sensitive species can function effectively as indicators of the changing status of other species within each assemblage because sampling was undertaken only once at each site.This study has provided one of the few opportunities to date to critically evaluate some aspects of the indicator species concept and its potential as a management shortcut for assessing changes in biodiversity in managed forest landscapes. Qualified support for the concept has been shown, based on the identification of a set of species apparently sensitive to logging and their representation across a range of species assemblages. The choice of candidate species for monitoring will depend on the integration of results from other experimental and retrospective studies, and will be specific to each region depending on the composition of species assemblages and the goals of management.