Suchergebnisse

Context The eastern bettong (Bettongia gaimardi) and the long-nosed potoroo (Potorous tridactylus) are mycophagous marsupials regarded as both keystone species and ecosystem engineers. Despite Tasmania being a refuge for these declining species, their niche partitioning is poorly understood. Aims Our aim was to identify factors that distinguish the distributions of B. gaimardi and P. tridactylus, and to develop a better explanation of their individual niches. Methods The Department of Primary Industries, Parks, Water and Environment conducted mammal surveys between 1975 and 2019. We used GIS to analyse these data, and geospatial information to identify relationships between B. gaimardi and P. tridactylus presence/absence and environmental variables. We then developed a model describing the distributions of these species in Tasmania. Key results Temperature seasonality (s.d. × 100), precipitation of wettest month (mm), precipitation of the driest month (mm), precipitation seasonality (coefficient of variation), the presence of vegetation dominated by Eucalyptus amygdalina and the presence of lowland grassy woodland/forest were the components in the best model for B. gaimardi. Our model broadly predicts that the distribution of B. gaimardi is restricted to the more fertile eastern half of Tasmania. P. tridactylus was associated with very few variables, with the presence of E. amygdalina–Eucalyptus obliqua damp forest being the only component in a very weak model. Transects with P. tridactylus and not B. gaimardi were more associated with rainforest and wet forest communities and areas of higher annual and wettest-month precipitation than were those with B. gaimardi and not P. tridactylus. Conclusions The importance of infertile sites to B. gaimardi may have been overstated in the literature, with moderate to high fertility being more characteristic of its range. B. gaimardi is adapted to persist in environments of low truffle (food) density, typical of the eastern half of Tasmania, through its ability to adopt a larger home range than for P. tridactylus, which requires dense ground vegetation. Implications Sites of high fertility in fragmented landscapes should be considered to be potential habitat for B. gaimardi. This challenges previous assumptions that infertile sites are the primary habitat of the species, with fertile sites offering poorer-quality habitat.

Since the 1980s in democratic societies, neoliberal reforms and neofeudal governance have transferred the delivery of many public goods and services from governments to non-government actors. Privatisation is a core neoliberal agenda, but little is known of the nature and extent of its application to nature conservation through reservation. We investigate the degree of privatisation of the expanding protected area system in our case study areas of Australia and Tasmania, hypothesising that governments have: disrupted public agencies managing the protected area estate by repeated reorganisation; diverted public funds from public to private protected areas; and increasingly alienated public reserves for subsidised private profit from tourism. We found frequent restructuring of agencies managing protected areas. Although Federal Government expenditure on private reserves increased markedly in the twenty-first century, so did expenditure on public conservation reserves. All States except Queensland increased public protected area funding. Direct subsidisation of private reserves by government has not had a steady upward trajectory. In contrast, subsidisation of private alienation of public conservation reserves for tourism may have accelerated in the twenty-first century. We conclude that, while Australian governments see value in protected areas as a source of economic development and electoral advantage, they are agnostic on ownership.

Context Understanding the diet of invasive species can inform the potential for their distribution into novel habitats. Fallow deer are well established in the grassy woodlands of central Tasmania, Australia, in environments generally considered to be their optimum habitat. They are also increasing their range. The potential range of fallow deer in Tasmania will depend on their ability to vary their diet to exploit new habitats. Diet flexibility will also determine the ecological impacts that fallow deer might have in novel habitats. Aims We compared the diets of fallow deer in a lowland grassy woodland, where deer have been established for over 150 years, with diets of deer in highland woodlands and forest with less grass cover and higher rainfall, where deer have been established for a shorter time (<50 years). We expected that fallow deer in grassy woodlands would mainly eat grass and forbs, and we wanted to know to what extent the diet of deer differed between habitats. Methods A metagenomic analysis was performed on fallow deer faecal pellets collected at one lowland and three highland study areas. The method was chosen to maximise information on taxonomic composition of diet and identify plant species that might be affected by deer herbivory to the lowest possible taxonomic level. Key results Fallow deer ate a wide variety of plant taxa. Diets varied among study areas. In the lowland study area, deer predominantly ate forbs and grasses. In the highland study area deer were more likely to browse on eucalypts and a variety of shrubs. Conclusions Fallow deer in Tasmania have a broad dietary niche. Availability of specific plant taxa is unlikely to limit fallow deer expansion into most new habitats. Implications Without stronger management strategies, deer are likely to further increase their range in Tasmania, including into areas with high conservation values. The potential impacts on these areas may be high.