22 research outputs found
Impacts of habitat fragmentation and linear clearings on Australian rainforest biota
No full text[Extract] Tropical forests are being destroyed and degraded at alarming rates (Achard et al. 2002; Hansen & DeFries 2004; Laurance & Peres 2006). The most common aftermath of large-scale forest conversion is a mosaic of relict forest fragments encircled by modified habitats, such as cattle pastures, soya and sugarcane farms, oil-palm plantations, slash-and-burn farming plots or scrubby regrowth. In addition, many internal clearings, such as highways, roads, power lines and gas lines, perforate surviving forest tracts. Hence, the tropical world is becoming ever smaller, more subdivided and further degraded by a range of external and internal disturbances (Goosem 1997; Laurance & Bierregaard 1997; Peres et al. 2006).
Although tropical rainforests comprise but a tiny fraction «0.2%) of the total land area in Australia, they are enormously important reservoirs of biological diversity and endemism, with a remarkably long evolutionary history that harkens back to the time when Australia was still part of Gondwana. As such, these forests are of exceptional international significance (Keto & Scott 1986; WTMA2004). This, in concert with the development of world-leading tropical researchers in Australia, has led to impressive advances in conservation-related research, especially within the Wet Tropics of Queensland World Heritage Area (WHA) under the aegis of the Cooperative Research Centre for Tropical Rainforest Ecology and Management
Rethinking road ecology
No full text[Extract] Over the past 17 years, sound ecologically based research into impacts has provided the information necessary, while changes in legislative policy have provided the impetus, to employ strategies for mitigation of the impacts of roads and highways through rainforest ecosystems. Such strategies include: road designs that avoid rainforest habitat or rehabilitation of habitat previously disturbed by redundant linear infrastructure; the maintenance or re-establishment of rainforest tree canopy above narrow roads and the identification and planting of tree species that create canopy over wider roads without dropping branches; the minimization of clearing width; engineering solutions for connectivity of habitat that include canopy bridges for arboreal animals and underpasses with furniture for cover or bridges that retain habitat underneath for terrestrial wildlife; the erection of powerlines or road bridges above the canopy. Collaboration between researchers, road authorities, government agencies and conservation groups has applied this research to upgrades of several roads and powerlines through Wet Tropics rainforest. Serial modifications of road designs and funding from Queensland Department of Main Roads (QDMR) for research into knowledge gaps ensured best practice environmental outcomes based on the latest research. The accumulated knowledge base is applicable to roads through rainforests throughout the world
Rainforest science and its application
No full text[Extract] The Wet Tropics of Queensland were inscribed on the World Heritage List on 9 December 1988 as a direct consequence of the accumulated scientific research and understanding of the region's rainforests up to that time. In 1992 the Wet Troplcs Management Authority was established as the body responsible for the coordinated management of the World Heritage Area, while the Rainforest CRC (Cooperative Research Centre for Tropical Rainforest Ecology and Management) was established in 1993 as the body responsible for both the coordination and the undertaking of scientific research to assist in the management of the World Heritage Area and associated rainforest landscapes.
Undertaking scientific research in World Heritage areas is more than a legitimate activity, it is also a duty. The importance of such research is explicitly acknowledged in Wet Tropics World Heritage legislation and in international conventions such as the World Heritage Convention and the Convention on Biological Diversity. One of the benefits that World Heritage areas provide for scientific researchers is the provision of protected benchmark and/or control sites where the direct impact of human activities is minimal relative to surrounding landscapes
Australian rainforests in a global context
No full text[Extract] Moist tropical rainforests cover approximately 6-7% of the surface of the globe and occur in a band about 15-20° either side of the equator. Typically they receive more than 2000 mm precipitation a year and although they may frequently experience a dry season, this is often punctuated by periods of heavy rainfall. These forests are typified by their evergreen nature, although some species of trees can be deciduous. Longer and drier dry seasons inevitably produce tropical dry forests, with most tree species being deciduous. Throughout this book when authors refer to rainforests they are referring to moist tropical rainforests
Impacts of tropical cyclones on forests in the wet tropics of Australia
No full text[Extract] Disturbances both anthropogenic and natural, shape forest ecosystems by controlling their species composition, structure and functional processes (Dale et al.2001), The tropical forests of the Wet Tropics of north-east Australia have been moulded by their land use and disturbance history over many millennia but particularly over the past 100 years (see Pannell, Chapter 4; Turton, Chapter 5; Laurance & Goosem, Chapter 23, this volume). Forests of the Wet Tropics region are subjected to a plethora of natural disturbances, including fire, drought, native pathogen outbreaks, floods, occasional landslides and tropical cyclones. All these natural disturbances interact in complex ways with anthropogenic disturbances across the Wet Tropics landscape, such as land-use change resulting from forest conversion to agricultural systems, earlier logging practices, urban and peri-urban development and expansion of the tourism industry (see Part III this volume).
As in many parts of the non-equatorial tropics (Whitmore 1974; Boose et al. 1994), tropical cyclones (a.k.a. hurricanes and typhoons) are significant disturbance phenomena for forest ecosystems in the Wet Tropics of north-east Australia, especially those near the coast. For this reason, even continuous forests in the region have been described as hyper-disturbed ecosystems with patches of damaged forest constantly recovering from previous cyclonic events, often in concert with floods, droughts and fires (Webb 1958). Cyclones are part of the ecosystem dynamics of these forested landscapes and recovery of canopy cover following such events is often remarkably rapid, although forest structure and composition may take many decades to recover. The same cannot be said for fragmented forests in the Wet Tropics, located within either an agricultural or grassland matrix. These forest fragments are particularly vulnerable to impacts of tropical cyclones and their associated strong winds, largely due to their high forest edge to area ratios (Laurance 1991, 1997). These fragments are also more prone to post-disturbance weed invasion and bush fires than nearby areas of continuous forest
Patterns and processes of inorganic nitrogen in the soil and flora of five successional stage subtropical rainforest communities
No full textGap Analysis of Environmental Research Needs in the Australian Wet Tropics
No full textEnvironmental research involves "understanding how environmental systems function and interact, and the impact that humans are having on the environment". Strengthened linkages between terrestrial biodiversity researchers and end-users are desirable to reduce duplicative effort and achieve maximum return on public investment in applied research. To assist this process, our analysis provides a significant review and consultation process with the aim of identifying end‐user needs, research gaps and possible synergies, delivering a valuable resource for terrestrially focussed research providers and end-user groups.
This report provides a resource for research providers by helping to locate relevant research information more efficiently, and by ensuring that proposed research is strategic and targeted at the needs of the end‐users. It provides a resource for end-users by delivering a repository of biodiversity research that is digested and easily accessible, and by identifying the areas of research where stakeholder interests overlap. Finally, the report can also be used by funding bodies to help guide the prioritisation of resources into future biodiversity research in the Wet Tropics bioregion
Efforts to restore habitat connectivity for an upland tropical rainforest fauna: A trial of underpasses below roads
No full textFour large underpasses, specifically designed for movements by fauna, form part of a major road upgrade project on the Atherton Tablelands in northeast Queensland, Australia. We describe the design and rationale of a project to test their effectiveness in restoring habitat continuity for tropical rainforest fauna. The large blocks of upland rain¬forest divided by the road are recognized for their high faunal conservation significance, forming habitat for many rare or threatened species. Ecologists, road engineers and the Atherton Tablelands conservation community have united with a common conservation goal: to design the ‘furniture’ within the underpasses and accomplish rainforest revegeta¬tion to provide protective cover and attract fauna to underpass entrances. Prior to con¬struction, small mammals were trapped weekly for several months in habitats close to the road upgrade. The small mammal community comprised grassland species in abandoned pasture and differed significantly from the rainforest specialists found in three closed canopy habitats: rainforest edge, rainforest interior and Lantana shrubland. Rainforest restoration works designed to restore connectivity for rainforest fauna across this aban¬doned pastureland (via the underpasses to major rainforest blocks to the north and south of the road) are currently in progress. Monitoring of the effectiveness of the underpasses in allowing faunal movements will involve the use of infra-red-triggered cameras within the underpasses and near underpass entrances, and a survey of road-killed fauna both prior to and postconstruction. Further examination of small mammal community structure and movements, with respect to both the new road and the underpasses, will be undertaken once rainforest plantings have become established. This evaluation should provide insights for further road-associated restoration projects in rainforest regions
Are less vocal rainforest mammals susceptible to impacts from traffic noise?
No full textContext: Traffic noise is believed to cause road avoidance and other barrier effects in a variety of wildlife species, and to force changes to call pitch or loudness in others; however, this has never been tested in the absence of other road impacts. Noise impacts on species that do not frequently vocalise are also poorly understood. We investigated traffic-noise impacts on the following three rainforest mammals that do not often vocalise: Hypsiprymnodon moschatus, Uromys caudimaculatus and Perameles nasuta. These species have previously been observed to exhibit varying levels of road avoidance.
Aims: To determine whether traffic noise affects movement and behaviour of medium-sized, ground-dwelling rainforest mammals in the absence of other road-associated variables and potential impacts. We hypothesised that noise impacts would be greatest for species previously shown to avoid roads. Noise impacts on these less vocal species compared with more vocal species is also discussed.
Methods: In north-eastern Queensland, Australia, mammals captured at least 500 m from any road were tracked after fitting with spool-and-line equipment. On noisy nights, traffic noise at levels similar to a busy highway was played continuously throughout the night from a line of 12 speakers mounted on trees. Speakers were silent on quiet nights.
Key results: Traffic noise caused no increase in avoidance of the speaker line and was not a barrier to movements across the line. Overall, movement paths on noisy nights appeared similar in pattern (tortuosity) to those of quiet nights. At a finer scale, movements of H. moschatus and P. nasuta became more tortuous later in the track, suggesting a return to normal foraging behaviour and possible habituation to the noise.
Conclusions: These three species with varying levels of previously recorded road avoidance, did not respond negatively to traffic noise. There was, however, a suggestion of habituation by H. moschatus and P. nasuta in response to the noise.
Implications: The demonstrated lack of response to traffic noise in these less vocal species means that traffic noise is unlikely to cause road avoidance or barrier effects. Instead, lack of response and possible habituation to traffic noise may increase vulnerability to road mortality
