Alpine and subalpine ecosystems are threatened by changing climate and disturbance regimes because they exist under extreme geographical and climatic conditions. Understanding the threats to and risk status of alpine and subalpine ecosystems is vital to guide their conservation, inform monitoring programs and identify the relative impact of activities currently degrading these ecosystems. We applied the IUCN Red List of Ecosystems criteria to 15 alpine and subalpine ecosystem types across Australian mountains. We found that seven ecosystem types were classified as threatened and three as Near Threatened, together accounting for 83% of the alpine and subalpine region. The primary threats were climate change and associated changes in fire regimes. There were insufficient data to quantify the environmental or biotic integrity of six ecosystem types, and one ecosystem type was listed as Data Deficient overall. Our study highlighted key knowledge gaps in the integrity of alpine and subalpine systems that limited our capacity to reliably assess risk to these ecosystems. We recommend expanding on-ground monitoring of ecosystem integrity to improve understanding of risks, key threats and actions to mitigate them. To reduce risks to these ecosystems, climate change must be aggressively mitigated, collateral pressures from invasive plants and animals must be reduced, and critical knowledge gaps that will allow conservation action prioritisation must be quickly filled. These strategies should be co-ordinated, resourced and enacted urgently in cross-jurisdictional Alps-wide work plans.

Aims: Australia's coastline is fringed by more than 8000 continental islands. These islands feature a diverse array of landforms, rock and soil types and geological origins. Some of these islands are among the least invaded, most pristine habitats in Australia and support high plant diversity. Here, we present a new Australia-wide curated dataset for plant species occurrences on islands. Results: Combining information from 1349 species lists and floras, A-Islands includes data on > 6500 plant species from 844 islands ranging in size from 18 m(2) to 4400 km(2), exhibiting different degrees of isolation from the mainland, and spanning all major Australian climate zones. Of these, 251 islands have been repeatedly sampled up to 11 times, making it possible to investigate temporal compositional change. A-Islands is open access and will be continuously updated. Its simple data structure, consisting of three comma-separated files allows easy integration with other Australian and global plant-occurrence databases and can serve as a repository for island research in Australia. Conclusions: Knowing which species occur on Australia's islands will provide opportunities for future research, including studying changes in biodiversity and species turnover within and among archipelagos, tests of classical island biogeography theory, and as a baseline for ecological monitoring and conservation.

We apply a relational multiscalar model of the sustainability of social organisation to the management of COVID-19 in Australia to analyse systems resilience and outcome fairness. Our model encompasses the structures, processes, functions, and contents of social organisation across micro, meso, and macro scales. We developed four data sets linked to COVID-19 and analysed these as variables in our model: (1) letters to the editor in public newspapers; (2) net weekly payroll jobs growth; (3) income/wealth inequality; (4) COVID-19 mortality and case/infection rates. These variables are used as proxies for democratic systems resilience, economic systems resilience, socioeconomic systems fairness, and public health systems efficacy, respectively. We found that as the pandemic progressed, public opinion shifted from favouring structural-societal transformation to favouring incremental adaptation. Spatial scale and geographical location impacted the resilience of weekly payroll jobs, with 'urban'/densely populated areas having less job growth than 'regional'/less dense locations, and 'national' scale net jobs growth being greater than 'job growth in New South Wales, Tasmania, and Victoria, in decreasing order. Transitions in pandemic policies of border restrictions and vaccination constrained net job losses, or enabled net gains over time, with the federal JobKeeper wage support preventing 'breakout' unemployment. Mobility restrictions and vaccination minimised mortality rates with self-administered (RAT) testing possibly decreasing infection rates. While our findings affirm that the complexity and 'messiness' of social policy means that management outcomes are not easily predictable nor will necessarily match expectations, our model provides a framework for assessing system dynamics and outcome fairness.

Context Vegetation remnants enveloped by built up areas tend to drift away in their character from vegetation on similar sites in more extensive patches of native vegetation, but may stabilise in synthetic (novel) form with time in harmony with disturbance regimes and environmental change. Managers may be able to induce a synthetic state that maintains the nature conservation values of such remnants. Aims We examine the degree to which the nature conservation values of the the vegetation of a 19th century urban reserve in nipaluna (Hobart), lutruwita (Tasmania) changed between 1974 and 2022/23 in a period of climate change and changes in vegetation management, with the aim of discerning appropriate conservation management regimes. Methods Sixty-nine 1 × 15 m quadrats were randomly located in the non-cultivated part of the Domain in 1974 and roughly relocated for sampling in 1984, 1994, 2001 and 2022. Tree diameters were recorded using the point-centred quarter method in 1974, 1984, 1994, 2001 and 2023. The responses of native and exotic species richness, and the frequency of the more common species, to time and other predictor variables related to time since last fire, evidence of mowing at the time of the survey, and topography were determined using linear modelling, correlation, analysis of variance and chi-squared. Key results The native tree Allocasuarina verticillata was the only significantly varying consistent increaser of 67 taxa. The native perennial herbs Acaena echinata and Leptorhynchos squamatus and the non-native shrubby weed Chrysanthemoides monilifera were the only significantly varying consistent decreasers. However, several rare and threatened species too infrequent for statistical analysis also declined between 2022/23 and 2000. Twenty-four of the 67 taxa with sufficient data for analysis did not significantly vary among years. The percentage of native species in quadrats did not change through time. It was negatively related to mowing and the time since fire. Native tree stems 10–30 cm in diameter and those over 30 cm increased through time, whereas those less than 10 cm in diameter increased dramatically until 2000, then strongly decreased by 2023. Total stem density increased through time. Conclusions Mowing and fire regimes strongly influenced the distributions of a large proportion of native taxa independent of time and underlying environment, largely by controlling the density of the small tree layer, which can potentially form closed-forest without eucalypts. Implications It is possible to use fire, mowing and slashing to maintain nature conservation values in synthetic urban grassy woodland, although the maintenance of the rarest native species requires more specific and varied interventions.

The gathering and hunting humans who evolved from earlier manifestations of Homo changed the distribution of forests on the planet through their use of fire to direct biological productivity to their sustenance, and through their contribution to the elimination of much of the global terrestrial megafauna. Land clearance at any scale awaited the development of agriculture, the several independent origins of which may indicate that it is an emergent outcome from the combination of a social animal who can transmit knowledge through generations and who lives in environments that support high numbers of food plants. The transition from uncleared forest and treeless land to land cleared for agriculture was slow, often reversed, and limited by the necessity to produce more energy in food production than in the inputs that created comestibles. Increases in cleared land until the nineteenth century were largely a product of the displacement of gathering and hunting people by disease-ridden European agriculturalists and world trade imposed on non-Europeans by colonialists. The explosion in fossil fuel usage from the nineteenth century onwards enabled exponential growth in human populations and cleared land, with the consequence of a crash in forest cover. Ironically, attempts to mitigate global warming caused by increased fossil fuel use, deforestation and land clearance have resulted in more land clearance for biofuels. While settlements, roads, logging, plantation establishment and dam construction have all contributed to the decrease in the native terrestrial cover of the planet, their contribution has been minor compared to the massive impact of agricultural development.

The effects of grazing and browsing by terrestrial vertebrates are poorly understood for southern hemisphere saltmarshes, many of which are recovering from stock grazing. We investigated whether the native late-successional shrub, Tecticornia arbuscula, regenerating several years after the cessation of stock grazing, was grazed by wild herbivorous mammals to the degree of impeding recovery. We measured T. arbuscula growth parameters in exclosures and adjacent controls for two years and used camera trapping of animals across four consecutive austral seasons to indicate grazing pressure. Height growth was more affected by exclosure from grazing than lateral change. Notably, grazing did not prevent the recovery of the shrubs from stock grazing at either site, suggesting that the growth rate of T. arbuscula relative to total grazing pressure is at sustainable levels and these shrubs are in a trajectory of recovery, with the smaller plants growing the fastest. Also, we found little difference between our two sites in grazing impact, despite one site having twice the number of animals, largely native macropods, as the other site, which was dominated by introduced lagomorphs (rabbits and hares). These findings further the knowledge of native and non-native terrestrial vertebrates in austral saltmarsh ecology and conservation.

Context Alpine ecosystems are threatened by warming and an associated increase in fire frequency. There is a gap in our knowledge of succession in Tasmanian alpine heath more than 50 years after fire. The literature suggests that the alpine successional progression usually involves decreasing rates of change, decreasing differences among fire ages, ongoing transitions among shrub species, ongoing transitions from some lifeforms/species to others, and that warming results in increases in species richness. Aims We test for these tendencies up to 75 years from fire in alpine vegetation on kunanyi/Mount Wellington, Tasmania, Australia. Methods We documented the changes in vegetation structure and composition between 1998 and 2022 in plots on either side of an alpine fire boundary in the alpine heathland and used earlier data and observations to extend the record of change after fire to 75 years. We put these changes in the context of the only area of alpine vegetation that was not burnt in 1947 or later. Key results The area last burnt in 1947 exhibited declines in all lifeform covers between 1998 and 2022. All lifeforms except tall shrubs and mat shrubs declined in cover in the area last burnt in 1962. By 2022, shrub cover in the 1962-burnt area had not attained equivalence with the area last burnt in 1947. Herbs had the most dramatic decline in both fire-age classes. There were few shrub seedlings in 2022. All but six taxa, three being exotic, were observed in both the plots and previous broader surveys. Increases in species richness caused by the upward migration of lower-elevation species were not observed. The long-unburnt patch lacked the major dominant of the 1947-burnt plots, namely Orites acicularis, and was dominated by a gymnosperm absent from most of the mountain. Conclusions Succession follows the initial floristic composition model. The differences in trajectories from the 1947 and 1962 fires could possibly be due to desiccation or abrasion damage from increasing wind speeds and temperatures. There are strong indications of further potential change in the absence of fire. Implications The slow rate of recovery and its on-going nature emphasise the importance of keeping fire out of this vegetation type.

If palaeoendemic invertebrates depend on palaeoendemic plants, and the latter are threatened by an increase in fire incidence, there is a possibility of an extinction cascade. We test whether there is co-occurrence of palaeoendemic plants and invertebrates in the proximity of a 52-year-old fire boundary in subalpine Tasmania, Australia. We used 2 x 2 m quadrats to record the incidence and cover of vascular plants and trapped invertebrates at each of these 33 sites in six time periods using an alpine Malaise trap and a CD sticky trap. The number of co-occurrences of palaeoendemic plant taxa with palaeoendemic invertebrate taxa was greater than expected by chance (p = 0.020), but many palaeoendemic invertebrates co-occurred with non-palaeoendemic plants. Some of the palaeoendemic invertebrate taxa that were associated with palaeoendemic plants were monophagous, while others were associated with environmental conditions created by a long absence of fire. Many may be threatened if increasing fire incidence destroys vegetation dominated by palaeoendemic plants. Palaeoendemic invertebrates are associated with palaeoendemic vascular plants more than could be expected by chance in alpine/subalpine ecosystems on either side of a 52-year-old fire boundary. However, some palaeoendemic invertebrates are generalists in their associations with plant species.image

Most alpine ecosystems are subject to non-native species invasion as climate warms and human disturbance increases. Therefore, it is important to identify the main barriers and facilitators of alpine plant invasions. While there is much research in continental alpine areas, there is limited research in maritime environments, which have distinctive biological, edaphic and geomorphologic features due to the scarcity of snow in winter. Here, we examine the contribution of anthropogenic and biotic factors on non-native plant invasions in the alpine areas of lutruwita (Tasmania), Australia. Specifically, we test whether disturbances associated with roads and livestock grazing facilitate non-native plant invasion and if biotic resistance from native plants and wild grazing animals inhibits such invasion. We used floristic data from: a statewide database; data from long-term grazing exclosures, and data from paired quadrats on roadsides and natural vegetation. Our results showed that non-native plants were associated with roadside disturbance and livestock grazing, with the latter having a legacy effect of 50 years. The persistent effect of stock grazing was evident in the exclusion experiment monitored over 30 years, where non-native plants occurred sporadically in time and space. In contrast, we found that the presence of wild grazing mammals, complete vegetation cover and high native richness, restricted non-native plants, emphasizing the importance of biotic resistance in controlling non-native plant invasions. These results indicate that livestock removal and road closure could be effective in reversing non-native plant invasion in this and other areas with wild vertebrate herbivores and high plant cover.

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.

Fish use of saltmarsh varies spatially, temporally, and with environmental conditions. The specific impact of these effects on fish assemblages in southern temperate Tasmania, Australia—the only mangrove-free Australian state—is as yet largely unknown. Seasonal variation in fish abundance, richness, diversity, and size was investigated in succulent saltmarshes in three estuaries (Marion Bay, Barilla Bay, and Ralphs Bay) in south-eastern Tasmania. All parameters varied between sampling locations. Greater numbers of fish were recorded at two sites (Marion Bay, mean density and standard error of 396.9 ± 71.3 individuals per 100 m2; Barilla Bay, mean density and standard error of 94.1 ± 30.1 individuals per 100 m2) than have been previously reported in Australian saltmarshes. Fish abundance was greatest in July–August (mean density and standard error of 200.2 ± 49.7 individuals per 100 m2) reflecting the breeding patterns of the numerically dominant Atherinosoma microstoma. Both abundance and species richness responded positively to water temperature in ordinal logistic regression models, and species richness and diversity increased with water depth in the models. It is likely that the strong differences between sampling locations are partly related to differences in water depth and water temperature between the estuaries. They may be also related to the habitat context of each estuary, especially the presence or absence of seagrass. The greater numbers of fish found in the present study relative to abundances reported in mainland Australia may relate to the absence of mangroves and the consequent differences in seascape habitat context, including greater water depths in marshes. Importantly, these results demonstrate that temperate southern hemisphere saltmarshes are year-round habitat for fish, thus emphasising their importance as a fish habitat.

Context It is important to understand the way in which wild herbivore grazing affects decadal vegetation dynamics after cessation of unnatural disturbances, especially in a context of climate change. Aims We investigated the decadal effects of different grazing regimes on treeless subalpine vegetation recovery from stock grazing and burning, on sites of different environmental character and initial state. Methods At each of four sites, two fenced areas that excluded mammalian herbivores, two that allowed in only rabbits and two grazed control plots were monitored every 5 years between 1991 and 2021. General linear models were developed to explain variation in change over the 30 years in different cover types. The years in which peak and trough values occurred were also determined, as were the incidence and direction of differences between treatments in sites and years. Key results There was marked variation in change over 30 years between the sites and lifeforms. Exclusion of mammalian herbivores increased the slow rate of revegetation. There was little effect from rabbits by themselves. Unexpectedly, the cover of both short and tall herbs was not promoted by grazing exclusion. Short term climatic variation affected some cover types, with many peaks and troughs in the dry year of 2001, but it was not possible to disentangle decades scale climate change effects from the process of recovery after disturbance. Conclusions The slight increase in revegetation rates in the absence of native herbivores and rabbits does not justify culling. Restoration interventions appear to be unnecessary. The prospect of increasing fire incidence and deer numbers suggests that it is desirable to continue monitoring the plots.

Australia's coastline is fringed by more than 8,000 continental islands. These islands feature a diverse array of landforms, rock and soil types and geological origins. Some of these islands are among the least invaded, most pristine habitats in Australia and support high plant diversity. Here, we present a new Australia-wide curated dataset for plant species occurrences on islands. Combining information from 1,349 species lists and floras, A-Islands includes data on >6,500 plant species from 844 islands ranging in size from 18 m2 to 4,400 km2, exhibiting different degrees of isolation from the mainland, and spanning all major Australian climate zones. Of these, 251 islands have been repeatedly sampled up to 11 times making it possible to investigate temporal compositional change. A-Islands is open access and will be continuously updated. Its simple data structure consisting of three comma separated files allows easy integration with other Australian and global plant-occurrence databases and can serve as a repository for island research in Australia. Knowing which species occur on Australia's islands will provide opportunities for future research, including studying changes in biodiversity and species-turnover within and among archipelagos, tests of classical island biogeography theory and as a baseline for ecological monitoring and conservation. ### Competing Interest Statement The authors have declared no competing interest.

The alpine vegetation of Australia is highly variable in its floristic composition and structural attributes with most of the variation being in the island state of Tasmania. There are several recognised centres of local endemism within alpine Australia. Throughout glacial periods in the northern hemisphere large ice sheets have covered most of the area occupied by alpine and tundra vegetation during interglacials, making alpine and tundra vegetation more extensive in interglacials than glacials. The chapter examines correlates of localised distributions of obligate alpine species within Australia. Vascular plant species lists were obtained from 75 alpine habitat islands throughout the range of alpine vegetation in Australia. There is no indication that the long-term major disjunction between the Tasmanian and mainland Australian alpine areas has had a major effect on species composition beyond that occasioned by environmental distance.

The Grey Goshawk is an endangered raptor occurring at low densities throughout its Tasmanian range. Nesting ecology and conservation requirements of the species are poorly understood. Thus, knowledge of nest site selection and breeding habitat preferences is needed to inform conservation management strategies. Here, we investigate nest site selection in a modified anthropogenic landscape in south-east Tasmania, Australia based on 75 active nest sites. Our logistic regression models show that nest site selection is influenced by a range of variables at the landscape, nest stand and nest site level, which likely relate to territoriality, food availability and forest structure. We also used environmental and disturbance-related variables to deliver a management-specific model, which indicated distance to track, dwelling and drainage lines were significant predictors of nest site selection. Our results can be used to improve conservation management and planning strategies.

Human societies face planetary crises of climate change, biodiversity loss and pollution. Conventional command-and-control approaches to manage these existential challenges have failed due to limited comprehension of relationships in social-ecological systems. To address this problem, we study the complex case of the disaster response to unprecedented floods in the Northern Rivers Region, New South Wales, Australia, in 2022. We apply a novel relational-systems model that identifies management structures, processes, functions and contents interacting at and across scales. The model helps identify the root causes in the inadequate disaster response that ensued in the Northern Rivers Region flooding. The root causes are a lack of systems-thinking competence, poor collaborative capacity, vulnerabilities in environmental management and deficient governance systems. The relational complexity concepts of self-organisation and socio-cultural organisation may further help explain variation in response to disasters in different socio-ecological contexts. Such understanding can inform individual and collective environmental action.

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.

Vegetation changes in saltmarsh habitat can influence fish assemblages and abundance. In Tasmania, Australia, mid‐latitude succulent saltmarsh communities have been invaded by the introduced tall grass, Spartina anglica. Eradication efforts have been ongoing since the 1990s with purported benefits for fish access to intertidal foraging grounds, but a lack of knowledge of the impact of S. anglica on fish limits understanding of the benefits and effectiveness of native habitat restoration. Here, we investigate whether fish assemblages in native saltmarshes and non‐native S. anglica grassland differ in species diversity, fish abundance, and size class distribution. We used buoyant pop nets to sample fishes in Sarcocornia quinqueflora herbland and S. anglica grassland swards at three sampling stations in northwest Tasmania. Very few individuals and low species diversity were recorded in both vegetation types at the sampling station with the most well‐established S. anglica infestation. Elsewhere, richness and diversity were higher in S. quinqueflora herbland. Overall fish abundance was higher in S. quinqueflora than in S. anglica, with a very strong effect at one sampling station. Fewer small individuals of the numerically dominant Atherinosoma microstoma were recorded in S. anglica, potentially indicating impaired nursery function. Our results provide important insights for S. anglica control, as we are the first to demonstrate a relationship between S. anglica presence and fish characteristics in southern Australian saltmarsh. These results indicate that S. anglica control is valuable for fish conservation. An extension of our research to document the effects of S. anglica removal on fishes is desirable.

Urban development is thought to negatively affect most native mammals. Here we assess whether adjacent suburbia, fire regime and vegetation influence the activity of mammal species in a reserve in Hobart, Tasmania, Australia. We used multiple regression to analyse the relationship between distance from houses, fire history, vegetation structure and floristics, and mammal activity, derived from camera visits and signs. Animal diggings and visits by long-nosed potoroos, southern brown bandicoots and cats were greater close to houses, while visits by red-necked wallabies, rufous-bellied pademelons, brushtail possums and short-beaked echidnas were not. The structure of the vegetation, particularly related to shelter, was important in many models. Many models also included floristic ordination axes that reflected drainage, fire regime and distance from high-density housing. Positive relationships between the introduced predatory cat and some of its potential native prey animals may reflect the influences of close proximity to suburbia, such as elevated domestic mesopredator populations, and elevated resource availability in domestic gardens. Our results suggest that urban areas can have a valuable role in nature conservation, despite, or because of, their effects on remnant native ecosystems.