Warming suppresses grassland recovery in biomass but not in community composition after grazing exclusion in a Mongolian grassland

We conducted a 4-year temperature manipulation experiment in a Mongolian grassland to examine the effect of daytime and nighttime warming on grassland recovery after grazing exclusion. After constructing a livestock exclusion fence in the grassland, we established daytime and daytime-and-nighttime warming treatments within the fenced area by a combination of open-top chambers (OTC) and electric heaters. We measured the numbers of plants and aboveground biomass by species after recording percentage vegetation cover every summer for three warming treatments inside the fence-non-warming, daytime warming, and daytime-and-nighttime warming-and for the grassland outside of the fence. OTCs increased daytime temperature by about 2.0 °C, and heaters increased nighttime temperature by 0.9 °C during the growing period. Grazing exclusion had little effect on grassland biomass but reduced the abundance of poorly palatable species and modified plant community composition. Daytime warming decreased soil moisture and lowered aboveground biomass within the fenced grassland but had little effect on plant community composition. Nighttime warming lowered soil moisture further but its effects on grassland biomass and community composition were undetectable. We concluded that recovery of plant biomass in grasslands degraded by grazing would be lowered by future climate warming through soil drying. Because warming had little effect on the recovery of community composition, adverse effects of warming on grassland recovery might be offset by improving plant productivity through mitigation of soil drying by watering. Soil drying due to nighttime warming might have detectable effects on vegetation when warming persists for a long time.

Prospects for sustainable use of the pastoral areas of Australia’s southern rangelands: a synthesis

There is growing recognition of the need to achieve land use across the southern Australian rangelands that accommodates changing societal preferences and ensures the capacity of future generations to satisfy their own preferences. This paper considers the prospects for sustainable use of the pastoral lands based either on continued grazing or emerging, alternative land uses. After an overview of the southern rangelands environment, the status of the pastoral industry, its environmental impacts, and key issues for pastoral management, we propose four principles and 19 associated guidelines for sustainable pastoralism. Although some continued withdrawal of land from pastoralism is anticipated, we expect that pastoralism will continue throughout much of the region currently grazed, particularly in the higher rainfall environments in the east. Within these areas, sustainable pastoral land use should be achievable by the application of four broad management principles, as follows: (1) manage grazing within a risk management framework based on the concept of tactical grazing, (2) develop infrastructure to allow best management of both domestic and non-domestic grazing pressure, (3) incorporate management of invasive native scrub, where required, into overall, ongoing property management and (4) manage grazing to enhance biodiversity conservation at landscape scale. Application of these principles and guidelines will require the development of appropriate policy settings, particularly in relation to kangaroo management, climate change, and natural resource governance, together with innovative approaches to research, development and extension. Policy development will also be required if the new industry of carbon sequestration is to deliver socio-ecological benefits without perverse outcomes. Other emerging industries based on renewable energy or ecosystem services appear to have considerable potential, with little risk of adverse ecological consequences.

Traversing the Wasteland: A Framework for Assessing Ecological Threats to Drylands

Drylands cover 41% of the Earth's terrestrial surface, play a critical role in global ecosystem function, and are home to over two billion people. Like other biomes, drylands face increasing pressure from global change, but many of these ecosystems are close to tipping points, which, if crossed, can lead to abrupt transitions and persistent degraded states. Their limited but variable precipitation, low soil fertility, and low productivity have given rise to a perception that drylands are wastelands, needing societal intervention to bring value to them. Negative perceptions of drylands synergistically combine with conflicting sociocultural values regarding what constitutes a threat to these ecosystems. In the present article, we propose a framework for assessing threats to dryland ecosystems and suggest we must also combat the negative perceptions of drylands in order to preserve the ecosystem services that they offer.

Australian rangeland futures: time now for systemic responses to interconnected challenges

Australia’s rangelands contain wildlands, relatively intact biodiversity, widespread Indigenous cultures, pastoral and mining industries all set in past and present events and mythologies. The nature of risks and threats to these rangelands is increasingly global and systemic. Future policy frameworks must acknowledge this and act accordingly. We collate current key information on land tenures and land uses, people and domestic livestock in Australian rangelands, and discuss five perspectives on how the rangelands are changing that should inform the development of integrated policy: climate and environmental change, the southern rangelands, the northern rangelands, Indigenous Australia, and governance and management. From these perspectives we argue that more attention must be paid to: ensuring a social licence to operate across a range of uses, acknowledging and supporting a younger, more Indigenous population, implementing positive aspects of technological innovation, halting capital and governance leakages, and building human capacity. A recommended set of systemic responses should therefore (i) address governance issues consistently and comprehensively, (ii) ensure that new technologies can foster the delivery of sustainable livelihoods, and (iii) focus capacity building on a community of industries where knowledge is built for the long-term, and do all three of these with an eye to the changing demographics of the rangelands.

The efficacy of monitoring techniques for detecting small mammals and reptiles in arid environments

Context Accurate surveying and monitoring of biodiversity provides essential baseline data for developing and implementing effective environmental management strategies. Land managers in arid zones face the challenge of managing vast, remote landscapes that support numerous cryptic species that are difficult to detect and monitor. Although researchers and land managers are using an increasingly wider variety of monitoring techniques to detect and monitor species, little is known of the relative effectiveness and comparative costs of these techniques. Aims The present study simultaneously assessed the efficacy of three popular monitoring techniques utilised in the spinifex sand plains of arid Australia, namely, live trapping, sign surveys and passive infrared (PIR)-camera trapping. Methods We explored variations in capture rates and species richness for each technique and compared initial and on-going costs of the techniques over time. Key results Sign surveys detected the greatest number of species and groups overall. Detectability of small mammals and reptiles, as a target group, was greater using PIR cameras, although the probability of detection by each technique varied among specific species. PIR cameras were initially the most expensive technique; however, the low ongoing costs of maintaining cameras in the field meant that they became the most cost effective after eight survey periods. Conclusions Each of the techniques tested here showed biases towards the detection of specific groups or species in the spinifex sand-plain habitat of Australia. Regardless, PIR cameras performed better at detecting the greatest diversity of target species and financially over time. Implications To accurately survey species across vast areas and climate variations, studies often extend over long time periods. Many long-term studies would be likely to benefit financially from the increased deployment of PIR cameras alongside or in place of live trapping surveys, with little impact on the ability to monitor the presence of most species in the region.

Quantifying drylands' drought resistance and recovery: the importance of drought intensity, dominant life history and grazing regime

Projected global change will increase the level of land-use and environmental stressors such as drought and grazing, particularly in drylands. Still, combined effects of drought and grazing on plant production are poorly understood, thus hampering adequate projections and development of mitigation strategies. We used a large, cross-continental database consisting of 174 long-term datasets from >30 dryland regions to quantify ecosystem responses to drought and grazing with the ultimate goal to increase functional understanding in these responses. Two key aspects of ecosystem stability, resistance to and recovery after a drought, were evaluated based on standardized and normalized aboveground net primary production (ANPP) data. Drought intensity was quantified using the standardized precipitation index. We tested effects of drought intensity, grazing regime (grazed, ungrazed), biome (grassland, shrubland, savanna) or dominant life history (annual, perennial) of the herbaceous layer to assess the relative importance of these factors for ecosystem stability, and to identify predictable relationships between drought intensity and ecosystem resistance and recovery. We found that both components of ecosystem stability were better explained by dominant herbaceous life history than by biome. Increasing drought intensity (quasi-) linearly reduced ecosystem resistance. Even though annual and perennial systems showed the same response rate to increasing drought intensity, they differed in their general magnitude of resistance, with annual systems being ca. 27% less resistant. In contrast, systems with an herbaceous layer dominated by annuals had substantially higher postdrought recovery, particularly when grazed. Combined effects of drought and grazing were not merely additive but modulated by dominant life history of the herbaceous layer. To the best of our knowledge, our study established the first predictive, cross-continental model between drought intensity and drought-related relative losses in ANPP, and suggests that systems with an herbaceous layer dominated by annuals are more prone to ecosystem degradation under future global change regimes.

Principles and guidelines for managing cattle grazing in the grazing lands of northern Australia: stocking rates, pasture resting, prescribed fire, paddock size and water points – a review

Beef cattle grazing is the dominant land use in the extensive tropical and sub-tropical rangelands of northern Australia. Despite the considerable knowledge on land and herd management gained from both research and practical experience, the adoption of improved management is limited by an inability to predict how changes in practices and combinations of practices will affect cattle production, economic returns and resource condition. To address these issues, past Australian and international research relating to four management factors that affect productivity and resource condition was reviewed in order to identify key management principles. The four management factors considered were stocking rates, pasture resting, prescribed fire, and fencing and water point development for managing grazing distribution. Four management principles for sound grazing management in northern Australia were formulated as follows: (1) manage stocking rates to meet goals for livestock production and land condition; (2) rest pastures to maintain them in good condition or to restore them from poor condition to increase pasture productivity; (3) devise and apply fire regimes that enhance the condition of grazing land and livestock productivity while minimising undesirable impacts; and (4) use fencing and water points to manipulate grazing distribution. Each principle is supported by several more specific guidelines. These principles and guidelines, and the supporting research on which they are based, are presented.

Physiological stress in koala populations near the arid edge of their distribution

Recent research has shown that the ecology of stress has hitherto been neglected, but it is in fact an important influence on the distribution and numbers of wild vertebrates. Environmental changes have the potential to cause physiological stress that can affect population dynamics. Detailed information on the influence of environmental variables on glucocorticoid levels (a measure of stress) at the trailing edge of a species' distribution can highlight stressors that potentially threaten species and thereby help explain how environmental challenges, such as climate change, will affect the survival of these populations. Rainfall determines leaf moisture and/or nutritional content, which in turn impacts on cortisol concentrations. We show that higher faecal cortisol metabolite (FCM) levels in koala populations at the trailing arid edge of their range in southwestern Queensland are associated with lower rainfall levels (especially rainfall from the previous two months), indicating an increase in physiological stress when moisture levels are low. These results show that koalas at the semi-arid, inland edge of their geographic range, will fail to cope with increasing aridity from climate change. The results demonstrate the importance of integrating physiological assessments into ecological studies to identify stressors that have the potential to compromise the long-term survival of threatened species. This finding points to the need for research to link these stressors to demographic decline to ensure a more comprehensive understanding of species' responses to climate change.

Movement patterns of an arboreal marsupial at the edge of its range: a case study of the koala

BACKGROUND

Conservation strategies derived from research carried out in one part of the range of a widely distributed species and then uniformly applied over multiple regions risk being ineffective due to regional variations in species-habitat relationships. This is particularly true at the edge of the range where information on animal movements and resource selection is often limited. Here, we investigate home range size, movement patterns and resource selection of koalas Phascolarctos cinereus in the semi-arid and arid landscapes of southwest Queensland, Australia. We placed collars with GPS units on 21 koalas in three biogeographic regions. Home range sizes, resource selection and movement patterns were examined across the three regions.

RESULTS

Habitat selectivity was highest at the more arid, western edge of the koala's range with their occupancy restricted to riparian/drainage line habitats, while the more easterly koalas displayed more variability in habitat use. There was no significant difference between home range sizes of koalas at the western edge of the range compared to the more easterly koalas. Instead, variability in home range size was attributed to spatial variations in habitat quality or the availability of a key resource, with a strong influence of rainfall and the presence of freestanding water on the home range size of koalas. Within a 580 m spatial range, movement patterns of male and female paths showed a tortuous trend, consistent with foraging behavior. Beyond this spatial range, male paths showed a trend to more linear patterns, representing a transition of movement behavior from foraging to breeding and dispersal.

CONCLUSIONS

The difference in home range movement patterns and resource use among the different koala populations shows that behavior changes with proximity to the arid edge of the koala's range. Changes in home range size and resource use near the range edge highlight the importance of further range-edge studies for informing effective koala conservation and management actions, especially when developing species-specific adaptation responses to climate change.

Understanding ecosystem dynamics in South Australia’s arid lands: a framework to assist biodiversity conservation

Determining what level of investment is required, and where and how it is used, to maintain biodiversity across vast areas is difficult. In response to this challenge, the South Australian Department of Environment, Water and Natural Resources has developed an information framework known as the ‘Aridlands Landscape Assessment Framework’ (ALAF) to provide a systematic basis for identifying landscape-specific, coarse-filter priorities for conservation investment across the arid zone. The ALAF is an analytical and conceptual framework that seeks to define ecosystem components and ecological processes operating at a landscape level, and understand where these processes are not meeting the requirements of extant biodiversity. This requires a systematic process to identify plant communities that occur in distinct biophysical settings. The next step is to document the dynamic processes that drive change within these communities in space and time. When coupled with knowledge of the requirements of indicator flora and fauna, this understanding will allow identification of those components that are at greatest risk, where, and for what reasons. This paper provides an overview of each step in the ALAF process and outlines how the framework has been used thus far to inform conservation planning across Witjira National Park.

A more effective means of delivering conservation management: a ‘New Integrated Conservation’ model for Australian rangelands

Desert ecology features long time-frames and extreme seasonal unpredictability. In addition, Australia’s arid rangelands have unique social, cultural, land-use and land tenure characteristics that influence appropriate conservation management. These circumstances have not been adequately incorporated into current conservation models, which rely on statutory control and (inadequate) grant funding. Application and management of the capital supposed to finance an effective response to the unique features of Australia’s rangelands thus remains largely divorced from actual circumstances. This paper briefly describes these unique features and the structure and characteristics of the capital currently applied in natural resource management. It then outlines a new conservation approach – the New Integrated Conservation model – to better match the actual natural, cultural and institutional ‘ecology’ of Australia’s rangelands. The model has three elements: a new fiscal ecology, multiplex governance arrangements and the incorporation of multiple objectives and mixed approaches into conservation management.

Changes to land tenure and pastoral lease ownership in Western Australia’s central rangelands: implications for co-operative, landscape-scale management

The majority of arid and semiarid land in the Western Australian pastoral zone has a long history of livestock grazing within an extensive network of predominantly family-held pastoral leases. A variety of different groups have purchased pastoral leases in the last five decades and, for many, making a profit from pastoralism is no longer a priority. For the central rangelands of Western Australia, these groups have included: government agencies, who have purchased some 9% of pastoral leases by area; private conservation organisations (<1% purchased); aboriginal communities and groups (~7%); and mining companies (~13%). The purchases of pastoral leases by government agencies was designed to improve the conservation status of arid-zone ecosystems, and is the first step in a process of changing land tenure to a conservation reserve. This paper summarises the extent and other characteristics of these changes in land tenure and ownership of pastoral leases, and explores the implications for land management and conservation, stemming from these changes. It demonstrates that large areas of contiguous land with no or reduced domestic stocking can now be found in many parts of these rangelands, particularly in the Coolgardie, Yalgoo and Pilbara bio-regions, with some leaseholders actively managing land for the conservation of biodiversity and restoring sites degraded through past over-grazing. In some bio-regions, such land covers considerable proportions of sub-catchments, suggesting that broad-scale conservation management and restoration objectives may be realised. It is argued that to fully realise these objectives requires effective communication and co-ordination between land managers, including sharing of ideas, view-points and resources. In particular, mining companies, now major holders of pastoral leases in Western Australia, can play an important role in contributing to and even facilitating such objectives.

Pastoralists' perceptions of biodiversity and land management strategies in the arid Stony Plains region of South Australia: implications for policy makers

The implementation of rangeland biodiversity management strategies relies on the engagement and participation of key stakeholders, including local pastoralists (ranchers). Understanding pastoralists' knowledge of biodiversity, as well as their attitudes towards and perceptions of biodiversity management strategies, is fundamental for the development of efficacious rangeland management. This paper examines perceptions of biodiversity and land management strategies held by pastoralists in the Stony Plains region (SPR) of South Australia and reports on a survey, consisting of 45 questions, delivered to lessees and/or managers of pastoral leases within or on the edge of the SPR. Respondents generally agreed with prescribed land management strategies, but agreement did not mean that strategies were being implemented. The purchase of pastoral leases by government and/or conservation groups for biodiversity purposes was opposed strongly, which may present a barrier to collaborative land management. Pastoralists strongly agreed with several listed threats to biodiversity, but their feelings on climate-related threats were less strong. Attitudes to climate may have been influenced by above-average rainfall experienced during and preceding the survey period and by the climatic variability that characterises arid rangelands. Biodiversity conservation and the pastoral industry rely on collaborative rangeland management, non-bureaucratic communication, and an understanding among stakeholders of the attitudes and perceptions of other natural-resource users.

Livestock mobility in arid and semiarid Australia: escaping variability in space

Livestock mobility is practised by pastoralists to cope with some of the variability and unpredictability of limited forage resources and because a diverse portfolio of strategies is needed to manage risk. The global trend towards rangeland privatisation, fragmentation and land-use intensification is eroding many of the institutions that have traditionally facilitated pastoral mobility. While Australia’s pastoral industry was developed as a European private-property system, livestock mobility has recently been increasing, indicating an important response to variability regardless of a nation’s wealth or development. This paper discusses how opportunistic movements of livestock over large scales by trading grazing rights between enterprises are effective but imperfect. Knowledge about the trustworthiness of individuals and local environments is often limited and poorly monitored. There is scope for policy to support mobility by targeting these institutional failures. The Australian system of trading grazing rights can inform efforts to maintain spatial flexibility in the industrial era.

Sir Sidney Kidman: Australia's cattle king as a pioneer of adaptation to climatic uncertainty

There is little direct evidence about the business model used by the legendary cattle king, Sir Sidney Kidman. Kidman’s properties were invariably stocked at less than full capacity, and were generally contiguous, forming chains that straddled stock routes and watercourses in the most arid zone of central Australia. Railheads at the ends of the chains provided access to the main capital city markets, and Kidman’s drovers supplied a wealth of information on competing cattle movements. This combination of features effectively afforded strategic transport flexibility in the form of so-called ‘real options’, especially during severe region-wide droughts. Alternative perspectives, such as the vertical integration of Kidman’s operations, or spatial diversification of land holdings, offer only partial insights. Faced with a highly variable and unpredictable climate, combined with the onset of erosion and the spread of rabbits, Kidman exemplifies human ability to adapt creatively to exogenous environmental shocks such as climate change.

A framework for sustainable rangeland livelihoods

Natural environments around the world shape their human residents, whose land management practices in turn shape their natural environments. The trial-and-error process of learning how to live within a human-environment system is costly for lands and for people. However, groups who have lived in the same type of place over long periods of time have often developed similar practices. For 20 years, sustainable livelihood frameworks have been used to identify those effective practices and to make them clear to others. I developed the Sustainable Rangeland Framework (SRF) by comparing scientific reports, pastoral management plans, Aboriginal experiences and government programs to identify how very different rangeland landholders could work together to benefit our human-environment system. The SRF focuses on ways to build valuable assets. I found that all groups described six similar categories of assets: landscape, biodiversity, flexibility, skill, information and networks. Land managers use their assets to develop strategies that increase sustainability and reduce vulnerability to risk. The SRF helps land managers visualise how each decision balances productivity and vulnerability in the context of ecological, economic and social variability. I provide a set of six measures for groups to evaluate the effectiveness of their strategies in building stronger assets. Because the SRF clarifies the learning process and highlights the benefits of collaboration, rangeland groups can use this model to work together to develop more secure lives in our increasingly unpredictable environment.

Coded T-mark continuums: a graphical method for reporting rangeland monitoring data

In this paper we describe a new method of graphically presenting rangeland monitoring data as coded time-mark continuums. This method aims to provide people with an interest in rangelands (stakeholders) with succinct information, which they need to assess rangeland condition and change. This new method graphs data for indicators of rangeland condition as time or T-marks along gradients or continuums. The ends of these continuums are reference points, which are values for indicators defining highly functional to very dysfunctional rangeland systems. The T-marks for an indicator along its continuum are also coded as to how changes relate to combinations of recent seasonal conditions and longer-term management effects. Codes are based on a two-way matrix combining ‘seasonal quality’ (e.g. rainfall in a specified period relative to the long-term record) and expected responses from land management (i.e. increase, decrease or no change relative to that predicted from seasonal quality). Monitoring data available in the Australian Collaborative Rangeland Information System were used to illustrate the use of coded T-mark continuums. We show succinctly how one indicator changed in two different rangeland regions and how multiple indicators changed within one region.

The 'desert syndrome' - causally-linked factors that characterise outback Australia

The desert knowledge community has been motivated by the assertion that outback Australia is characterised by a set of features that are not individually unique, but which together cause it to function in ways that are fundamentally different to other physical and social environments. This paper sets out to appraise this assertion. It documents the evidence for the individual features – (i) climate variability at various scales in space and time (climate variability), (ii) widespread low and patchy primary productivity (scarce resources), (iii) sparse, mobile and patchy human population (sparse population), (iv) distant markets and decision-making (remoteness), (v) further perceived unpredictability in markets, labour and policy (social variability), (vi) limited research knowledge and persistent traditional and local knowledge (local knowledge), and (vii) particular types of people, culture and institutions (cultural differences). It then assesses whether there is evidence for the hypothesis that these features are causally linked to act as a consistent syndrome. This can only be partially confirmed as yet, but, if true, implies that management and policy for the region must recognise that the causal links are unlikely to be easily broken. The key consequence for desert people is that they should put more time into planning and managing for their apparently careless treatment by the environment and bureaucracy, and less time railing against it, because it will not go away. The key consequence for sympathetic outsiders is that there are great opportunities to create a policy context in which desert innovation can thrive in response to the ‘desert syndrome’.

The 'viability' and resilience of communities and settlements in desert Australia

There is a continuing policy debate about whether it is possible to have sustainable small settlements in outback regions of Australia, where there is low and variable primary production and a sparse and mobile population. This debate is focused largely on Aboriginal settlements, but applies equally to all desert dwellers. In this contribution, we review the sources of economic flows through settlements occupied by different communities with common livelihood sources, whether based on mining, grazing, tourism, cultural resources, welfare or services, concluding that most desert livelihoods depend directly or indirectly on temporally variable inputs. Individual remote settlements tend to be dominated by one such ‘community of livelihood’, and differ in nature according to the source of that livelihood. These create types of settlement and service aspirations which are alien to more densely settled regions. Settlement ‘viability’ is a measure of the short-term balance between aspirations for services (technical, social, but also for livelihoods and well being) and the costs of fulfilling these aspirations, and consequently is not a simple on/off switch – the community can adjust both its aspirations and the cost factors involved in meeting them. We define a resilient settlement as one that is viable in the long term in the face of its variable inputs. Thus, we determine that the concepts of settlement viability and resilience must be analysed differently according to the strategy adopted by different resident communities. In particular, Aboriginal (and pastoral) communities are particularly dependent on social and natural capital, yet these are not monitored. The whole analysis emphasises the importance of taking a demand- rather than supply-driven approach to services in desert settlements. Our conclusion is that, if top-down solutions continue to be imposed without appreciating the fundamental drivers of settlement in desert regions, then those solutions will continue to be partial, and ineffective in the long term.