Traffic noise impacts on urban forest soundscapes in south‐eastern Australia

While the negative impacts of road infrastructure on faunal diversity and abundance have been extensively studied, many traffic noise studies have been conducted in the presence of confounding factors. Therefore, the extent to which traffic noise alone is responsible for impacts is not well known and a better understanding is required to inform urban planning and management decisions. We examined the impact of traffic noise on soundscape patterns at road edges in urban forests. Acoustic sensors were deployed at road and powerline edges, as well as within interior habitat, at three sites in south‐east Queensland, Australia. Powerline edges were included to separate edge effects from traffic noise impacts. We used soundscape power (normalized watts per kHz) of technophony (traffic noise in the 1–2 kHz range) and biophony (animal sounds in the 3–11 kHz range) to investigate soundscape patterns. The results showed that biophony was consistently lower at road edges and was negatively correlated with traffic noise and positively correlated with distance to road edge. Technophony was higher at road edges and was found to correlate negatively with distance to road edge and positively with traffic noise. Technophony and biophony at powerline edges generally exhibited values comparable to interior habitat. These results indicate that traffic noise affects urban forest soundscape patterns at road edges in south‐eastern Australia.     

Importance of landscape context for post‐restoration recovery of riparian vegetation

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Influence of streamflow on spawning‐related movements of golden perch Macquaria ambigua in south‐eastern Australia

In this study, linkages were examined between movement and spawning behaviour for golden perch Macquaria ambigua in a lowland river by integrating acoustic telemetry and egg and larval drift sampling over 4 years. Movement was strongly seasonal, being most prevalent during the spawning season (spring to early summer), and occurred primarily downstream into the lower river reaches during elevated flows. A very strong association was found between the occurrence of spawning and long‐distance M. ambigua movement. The results also revealed that targeted environmental water allocation can promote movement and spawning of this species. By integrating multiple analytical approaches and focusing on key life‐history events, this study provides an improved picture of the life history and flow requirements of M. ambigua. The findings can help guide the development of effective environmental flow recommendations.     

The conservation of arboreal marsupials in the Albury‐Wodonga region of south‐eastern Australia

Urban expansion is a major cause of land use change and presents a significant threat to biodiversity worldwide. Agricultural land is often acquired by local councils and developers to expand urban growth boundaries and establish new housing estates. However, many agricultural landscapes support high biodiversity values, especially farmlands that feature mosaics of native vegetation and keystone habitat such as hollow‐bearing trees. In south‐eastern Australia, many arboreal marsupials including the threatened Squirrel Glider (Petaurus norfolcensis) have populations within peri‐urban zones of expanding rural cities. A key challenge to planners, developers and conservation organisations is the need to maintain habitat for locally rare and threatened species as land undergoes changes in management. Critical to the sustainable development of peri‐urban landscapes is a thorough understanding of the distribution, habitat requirements and resources available to maintain and improve habitat for species dependent on limited resources such as tree cavities. In this management report, we present background information on an integrated research programme designed to evaluate potential impacts of urban development on fauna in the Albury Local Government Area, NSW. We mapped hollow‐bearing trees, erected nest boxes and monitored arboreal marsupials. Information presented in this report provides a blueprint for monitoring arboreal marsupials, including threatened species in other developing regions, and will assist the Albury‐Wodonga local governments in future planning of sustainable living environments.     

Petals may act as a reward: myrmecochory in shrubby Darwinia species of south‐eastern Australia

The removal rates of fruits (the diaspore) were assessed in exclusion experiments in three shrubby species of Darwinia, endemic to the Sydney Basin of south‐eastern Australia. There was a clear pattern of fruit removal in just a few days by small species of ants from the genera Iridomyrmex, Crematogaster and Pheidole. When only ants had access to fruits an average of 41% of fruits were removed, whereas when only vertebrates had access an average of 13% of fruits were removed. There was some variation in the number of fruits removed both between species and within species across study sites or annual seed crops. When ants had access to seeds this variation in removal amounted to 10–80% over 1–4 days. Uniquely in Darwinia, it is the old petals (which remain attached to the fruit) that are attractive to the ants, rather than a specific lipid body. This likely represents a case of successful ecological fitting by Darwinia to take advantage of the widespread presence of myrmecochory in the Australian flora.     

Biodegradation of 1080: Testing soils in south‐eastern Australia for sodium fluoroacetate‐degrading micro‐organisms

Sodium fluoroacetate (1080) is a vertebrate poison commonly used for the control of vertebrate pests in Australia. Long‐term environmental persistence of 1080 from baiting operations has likely nontarget species and environmental impacts and is a matter of public concern. Defluorinating micro‐organisms have been detected in soils of Western and central Australia, and Queensland, but not in south‐eastern Australia. The presence or absence of defluorinating micro‐organisms in soils from south‐eastern Australia will assist in determining whether long‐term environmental persistence of 1080 is or is not occurring. Soils from the Central West Slopes and Plains and Central Tablelands of New South Wales were sampled to investigate the presence and capability of 1080 defluorinating soil micro‐organisms. Thirty‐one species of micro‐organisms were isolated from soils from each site after 10 days incubation in a 20 mM 1080 solution. Of these, 13 isolates showed measurable defluorinating ability when grown in a 1080 and sterile soil suspension. Two species, the bacteria Micromonospora, and the actinomycete Streptosporangium, have not been previously reported for their defluorinating ability. These results indicate that defluorinating micro‐organisms are present in soils in south‐eastern Australia, which adds weight to other studies that found that 1080 is subject to microbiological degradative processes following removal from the bait substrate. Soil micro‐organism defluorination, in combination with physical breakdown and uptake by plants, indicates that fluoroacetate in soils and natural water ways is unlikely to persist. This has implications for the better informed use of 1080 in pest animal management programmes in south‐eastern Australia.     

First record of pughead deformity in Cichla kelberi (Teleostei: Cichlidae), an invasive species in an estuarine system in south‐eastern Brazil

The first record of pughead deformity in a Neotropical freshwater fish not raised in captivity is provided, based on an adult male of Cichla kelberi introduced into an estuary of Rio de Janeiro State, south‐eastern Brazil. A general biological characterization of the specimen is provided and aspects of its aberrant anatomy are described. Environmental and biological factors that may cause pughead deformity in fishes are discussed.     

The impact of fire regimes on populations of an endangered lizard in montane south‐eastern Australia

The Blue Mountains water skink (Eulamprus leuraensis; Scincidae) is restricted to less than 40 fragmented swamp sites, all within the Blue Mountains and Newnes Plateau areas of New South Wales, Australia. Climate change is expected to increase fire frequency in the area, potentially degrading habitat quality for this endangered reptile. We quantified lizard abundances in 12 swamps using standardized surveys, and constructed a Global Information System (GIS) database to determine fire‐histories for each swamp since 1967. The abundance of Blue Mountains water skinks was negatively correlated with fire frequency, but not with time since fire. Indirect impacts of fire (mediated via shifts in vegetation density, moisture levels, prey availability and post‐fire predation) may be more important than direct effects in these cool, moist habitats. Although lizards were less common in swamps close to urban areas, and less common in frequently burnt areas, viable populations of this endangered reptile still persist even in anthropogenically disturbed swamps and in swamps that have experienced up to four fires in 20 years. Future research could usefully extend these analyses to other swamps in the locality, and explore the broader impacts of fire regimes on the distinctive flora and fauna of this threatened ecological community.     

Arthropod community composition along snowmelt gradients in snowbeds in the Snowy Mountains of south‐eastern Australia

Environmental gradients drive variation in community composition across a range of spatial scales. In alpine regions, areas of long‐lasting snow (‘snow patches’) create snowmelt gradients that drive considerable change in vegetation structure and composition over small spatial scales. This study examined whether there is parallel variation in arthropod communities using snowmelt gradients in the Australian Alps. Mites (Acarina) were the most common arthropods in snow patches, followed by springtails while, among the insects, the orders Hymenoptera (primarily Formicidae), Diptera, Coleoptera (primarily Carabidae) and Hemiptera (primarily Cicadellidae) dominated. Along the snowmelt gradient, arthropod assemblages changed from having equal proportions of predators and herbivores in early‐melting zones to being predator‐dominated in late‐melting zones, particularly early in the growing season. This followed a transition in vegetation cover and composition and was driven by higher numbers of predacious carabid beetles in later‐melting zones. Overall, however, our results suggest that snowbed arthropod communities in the Australian alpine zone are more sensitive to short‐term effects, such as time since snowmelt, than to differences in vegetation structure and composition or long‐term patterns of snowmelt. Continued advancement of snowmelt timing due to warmer spring temperatures is therefore likely to have more impact on the seasonality of snowbed arthropod communities than on the overall community composition.     

Species richness–environment relationships within coastal sclerophyll and mesophyll vegetation in Ku‐ring‐gai Chase National Park,New South Wales,Australia

Abstract Patterns in species richness from a wide range of plant communities in Ku‐ring‐gai Chase National Park, New South Wales, Australia, were examined in relation to a number of environmental variables, including soil physical and chemical characteristics. Total species richness and richness of three growth‐form types (trees, shrubs and ground cover) were determined in duplicate 500‐m² quadrats from 50 sites on two geological substrata: Hawkesbury Sandstone and Narrabeen shales and sandstones. Generalized linear models (GLM) were used to determine the amount of variation in species richness that could be significantly explained by the measured environmental variables. Seventy‐three per cent of the variation in total species richness was explained by a combination of soil physical and chemical variables and site attributes. The environmental variables explained 24% of the variation in tree species richness, 67% of the variation in shrub species richness and 62% of the variation in ground cover species richness. These results generally support the hypothesis of an environmental influence on patterns in total species richness and richness of shrubs and ground cover species. However, tree species richness was not adequately predicted by any of the measured environmental variables; the present environment exerts little influence on the richness of this growth‐form type. Historical factors, such as fire or climatic/environmental conditions at time of germination or seedling establishment, may be important in determining patterns in tree species richness at the local scale.     

The phytogeographical affinities of the Pitcairn Islands – a model for south‐eastern Polynesia?

Aim To identify how the Pitcairn group relates biogeographically to the south‐eastern Polynesian region and if, as a subset of the regions flora, it can then be used as a model for biogeographical analyses. Location The Pitcairn group (25°4′ S, 130°06′ W) comprises four islands: Pitcairn, a relatively young, high volcanic Island; Henderson, an uplifted atoll, the uplift caused by the eruption of Pitcairn; and two atolls, Ducie and Oeno. The remote location, young age and range of island types found in the Pitcairn Island group makes the group ideal for the study of island biogeography and evolution. Methods A detailed literature survey was carried out and several data sets were compiled. Dispersal method, propagule number and range data were collected for each of the 114 species that occurs in the Pitcairn group, and environmental data was also gathered for islands in Polynesia. Analyses were carried out using non‐metric multidimensional scaling and clustering techniques. Results The flora of the Pitcairn Islands is derived from the flora of other island groups in the south‐eastern Polynesian region, notably those of the Austral, Society and Cook Islands. Species with a Pacific‐wide distribution dominate the overall Pitcairn group flora. However, each of the islands show different patterns; Pitcairn is dominated by species with Pacific, Polynesian and endemic distributions, with anemochory as the dominant dispersal method (39.5%); Henderson is also dominated by species with Pacific, Polynesian and endemic distributions, but zoochory is the dominant dispersal method (59.4); Oeno and Ducie are dominated by Pantropic species with hydrochory as the most common dispersal method (52.9% and 100%, respectively). Main conclusions ? Habitat availability is the most significant factor determining the composition and size of the flora. ? South‐east Polynesia is a valid biogeographical unit, and should include the Cook, Austral, Society, Marquesas, Gambier, Tuamotu and Pitcairn Islands with Rapa, but should exclude Easter Island, Tonga and Samoa. ? Regionalization schemes should take island type into consideration. ? The Pitcairn Island group can serve as a useful model for Pacific biogeographical analyses.     

Contrasting habitat use of morphologically similar bat species with differing conservation status in south‐eastern Australia

The east‐coast free‐tailed bat Mormopterus norfolkensis Gray, 1839 is a threatened insectivorous bat that is poorly known and as such conservation management strategies are only broadly prescribed. Insectivorous bats that use human‐modified landscapes are often adapted to foraging in open microhabitats. However, few studies have explored whether open‐adapted bats select landscapes with more of these microhabitat features. We compared three morphologically similar and sympatric, molossid bats (genus Mormopterus) with different conservation status in terms of their association with vegetation, climate, landform and land‐use attributes at landscape and local habitat element scales. We predicted that these species would use similar landscape types, with semi‐cleared and low density urban landscapes used more than forested and heavily cleared landscapes. Additionally, we explored which environmental variables best explained the occurrence of each species by constructing post‐hoc models and habitat suitability maps. Contrary to predictions, we found that the three species varied in their habitat use with no one landscape type used more extensively than other types. Overall, M. norfolkensis was more likely to occur in low‐lying, non‐urban, riparian habitats with little vegetation cover. Mormopterus species 2 occupied similar habitats, but was more tolerant of urban landscapes. In contrast, Mormopterus species 4 occurred more often in cleared than forested landscapes, particularly dry landscapes with little vegetation cover. The extensive use of coastal floodplains by the threatened M. norfolkensis is significant because these habitats are under increasing pressure from human land‐uses and the predicted increase in urbanization is likely to further reduce the amount of suitable habitat.     

Long‐term effects of exclusion of grazing stock on degraded herbaceous plant communities in a riparian Eucalyptus camaldulensis forest in south‐eastern Australia

Abstract Stock grazing has degraded many riparian ecosystems around the world. However, the potential for ecosystem recovery following the removal of grazing stock is poorly known. We developed a conceptual model to predict the responses of native and exotic herbaceous plants to grazing exclusion, based on site productivity and the degree of initial vegetation degradation. The effects of excluding grazing stock on richness, cover and composition of herbaceous plants were examined over 12 years in the degraded understorey of a riparian forest in Gulpa Island State Forest in south‐eastern Australia. We predicted that grazing exclusion would lead to limited changes in vegetation cover, richness and composition, owing to presumed low site productivity and the high degree of understorey degradation. Results showed that the cover, richness and composition of native and exotic species varied significantly among years. Over all plots, regions and years, total cover was slightly but significantly lower in grazed than in ungrazed plots (43.4% vs. 50.8%). While the cover of native plants increased over time in both treatments, the rate of increase was slightly greater in ungrazed plots. Grazing exclusion had no effect on the richness of native or exotic species, but had a significant but minor impact on plant composition, with different common species (mostly exotics) being promoted or diminished in ungrazed plots. The composition of grazed and ungrazed areas did not become more different over time. Overall, the effects that could be attributed to grazing exclusion were relatively minor and transient. Results are consistent with predictions based on site productivity and initial degradation, and should not be extrapolated to other more productive, or less degraded, riparian systems.     

Long-term change in the floristic composition and vegetation structure of Carnac Island, Western Australia

Aim To document changes in the floristic composition and vegetation structure of Carnac Island during a period of 40 years. This paper presents a synthesis of all available floristic and vegetational information. Location Carnac Island is 8 km offshore from Fremantle, south‐west Western Australia. Methods Comparison of lists of plant species for 1951, 1958/9, 1966/7, 1975/6 and 1995–6. Comparison of vegetation, based on structural and floristic elements, for 1951, 1965, 1972, 1984 and 1995. Results Floristic composition (both native and exotic species) changed most dramatically in the period 1975/6–1995/6, with a 37% reduction in number of plant species. The number of annual and perennial native species present in 1995/6 was most similar to that in 1951. The most remarkable change in the flora has been the increase in annual exotic species since 1951. Immigration and extinction rates were greatest in the periods 1951–58/9 and 1958/9–1966/7, respectively. Vegetation structure has also altered, involving a reduction in height of dominant species from 3–4 m to 1 m as Acacia rostellifera and Olearia axillaris have declined in distribution. The weed species Mesembryanthemum crystallinum (first recorded 1975) and Malva parviflora (1958) now dominate the vegetation of half the island. Main conclusions Five factors are considered to have contributed to botanical change: nesting seabird populations, eradication of the rabbit in 1969, drought, increased saltload from occasional cyclones in summer or autumn, and competition from increasing dominance of several weed species. Several of these factors have operated in opposing ways with respect to plant species richness and vegetation cover. Experimental studies are required to determine the strength of these interactions. Two weed species, Zantedeschia aethiopica (first recorded 1966) and Lycium ferocissimum (1992) have the potential to dominate the vegetation of the island.     

Impacts of an invasive willow (Salix × rubens) on riparian bird assemblages in south‐eastern Australia

We explored how a woody plant invader affected riparian bird assemblages. We surveyed 15 200‐m‐long transects in riparian zones in a much‐changed landscape of eastern Victoria, Australia. Abundance, species‐richness, foraging‐guild richness and composition of birds were compared in transects in three habitat types: (i) riparian zones dominated by the invasive willow Salix × rubens; (ii) riparian zones lined with native woody species; and (iii) riparian zones cleared of almost all woody vegetation. We also measured abundance and richness of arthropods and habitat structure to explore further the effects of food resources and habitat on the avifauna. We observed 67 bird species from 14 foraging guilds. Native riparian transects had more birds, bird species and foraging guilds than willow‐invaded or cleared transects. Habitat complexity increased from cleared to willow‐invaded to native riparian transects, as did abundance of native and woodland‐dependent birds. Native shrub and trees species had more foliage and branch‐associated arthropods than did willows, consistent with a greater abundance and variety of foraging guilds of birds dependent on this resource. Willow spread into cleared areas is unlikely to facilitate greatly native bird abundance and diversity even though habitat complexity is increased. Willow invasion into the native riparian zone, by decreasing food resources and altering habitat, is likely to reduce native bird biodiversity and further disrupt connectivity of the riparian zone.     

Predicting impacts of south‐to‐north water transfer project on fish assemblages in Hongze Lake,China

The Chinese government implemented the ambitious south‐north water transfer project (SNWTP), which aims to transport water from the Yangtze to the north of China where water shortages are severe. Although the ecological impacts of this project have been addressed publically, there remains a poor understanding of the effects of such large‐scale water transfers on the populations of aquatic species. The potential ecological impacts of such water transfers on the Hongze Lake fish assemblages are assessed here using Self‐Organizing Map (SOM) and Random Forest (RF) modeling. Using SOM, twenty‐three fish species in 15 sampling sites were classified into two assemblages and four sub‐assemblages corresponding to four distinct habitats (deep water macrophytes, deep water bare silt, shallow water bare silt, and shallow water macrophytes). The RF model further showed that water depth and transparency were the abiotic drivers underpinning fish assemblages in Hongze Lake. As the SNWTP is forecasted to modify the distribution of water depth and water clarity, major knock‐on effects are expected on downstream lake fish assemblages.