Grazing lowers soil multifunctionality but boosts soil microbial network complexity and stability in a subtropical grassland of China

Introduction

Long-term grazing profoundly affects grassland ecosystems, whereas how the soil microbiome and multiple soil ecosystem functions alter in response to two-decades of grazing, especially how soil microbiome (diversity, composition, network complexity, and stability) forms soil multifunctionality is rarely addressed.

Methods

We used a long-term buffalo grazing grassland to measure the responses of soil physicochemical attributes, stoichiometry, enzyme activities, soil microbial niche width, structure, functions, and networks to grazing in a subtropical grassland of Guizhou Plateau, China.

Results

The evidence from this work suggested that grazing elevated the soil hardness, available calcium content, and available magnesium content by 6.5, 1.9, and 1.9 times (p = 0.00015-0.0160) and acid phosphatase activity, bulk density, pH by 59, 8, and 0.5 unit (p = 0.0014-0.0370), but decreased the soil water content, available phosphorus content, and multifunctionality by 47, 73, and 9-21% (p = 0.0250-0.0460), respectively. Grazing intensified the soil microbial carbon limitation (+78%, p = 0.0260) as indicated by the increased investment in the soil β-glucosidase activity (+90%, p = 0.0120). Grazing enhanced the complexity and stability of the bacterial and fungal networks but reduced the bacterial Simpson diversity (p < 0.05). The bacterial diversity, network complexity, and stability had positive effects, while bacterial and fungal compositions had negative effects on multifunctionality.

Discussions

This work is an original attempt to show that grazing lowered multifunctionality via the reduced bacterial diversity and shifted soil bacterial and fungal compositions rather than the enhanced bacterial and fungal network complexities and stability by grazing. Protecting the bacterial diversity from decreasing, optimizing the composition of bacteria and fungi, and enhancing the complexity and stability of bacterial network may be conducive to improving the soil multifunction of grazing grassland, on a subtropical grassland.

Impact of the Stress Status of Employees on the Enterprise Technology Management Cost Through Matter-Element Analysis Under Psychological Health Education

In this study, in order to analyze the stress sources and stress-coping strategies of employees in construction enterprises, to explore the influencing factors of enterprise technical management cost, and to offer suggestions for mental health education of employees, 372 employees of Shandong Construction Engineering Group Co., Ltd. were selected for a questionnaire survey. The influences of stress sources and stress-coping strategies on the mental health of employees were compared, based on different demographic variables. The evaluation model was constructed using the matter-element analysis to rank the factors influencing the enterprise technology management cost. The results showed that the stress value of work characteristics was the highest (4.26 ± 0.511), followed by the organizational structure and atmosphere (4.15 ± 0.382); stress-coping strategies at the individual level (1.84 ± 0.315) scored higher than that at the organizational level (1.67 ± 0.248) (P < 0.05). Notable differences were observed in balance between work and family between males and females (P < 0.05); in work characteristics, role orientation, personal relationship, and balance between work and family between subjects of different ages (P < 0.05); in work characteristics, and balance between work and family between the married and the unmarried (P < 0.05); and in role stress and work characteristics between subjects in different positions (P < 0.05). The evaluation results revealed that the factors influencing the technology management cost of enterprises included price index, development cost, fixed investment proportion, power equipment rate, mechanical artificial intelligence, labor cost, rate of technical equipment, the output value, informatization of technology management, and national policy. In conclusion, the two major sources of stress for employees in Luoyang Construction Engineering Group Co., Ltd. were as follows: (1) work characteristics and (2) organizational structure and atmosphere. Besides, many employees adopted the stress-coping strategies at the individual level, and enterprises needed to strengthen the psychological health education for employees at the organizational level. In practice, the enterprise needed to add importance to the development of mechanical artificial intelligence, informatization of technology management, and national policy.

Is ground cover a useful indicator of grazing land condition?

Remotely sensed ground cover data play an important role in Australian rangelands research development and extension, reflecting broader global trends in the use of remotely sensed data. We tested the relationship between remotely sensed ground cover data and field-based assessments of grazing land condition in the largest quantitative analysis of its type to date. We collated land condition data from 2282 sites evaluated between 2004 and 2018 in the Burdekin and Fitzroy regions of Queensland. Condition was defined using the Grazing Land Management land condition framework that ranks grazing land condition on a four point ordinal scale based on dimensions of vegetation composition, ground cover level and erosion severity. Nine separate ground cover derived indices were then calculated for each site. We found that all indices significantly correlated with grazing land condition on corresponding sites. Highest correlations occurred with indices that benchmarked ground cover at the site against regional ground cover assessed over several years. These findings provide some validation for the general use of ground cover data as an indicator of rangeland health/productivity. We also constructed univariate land condition models with a subset of these indices. Our models predicted land condition significantly better than random assignment though only moderately well; no model correctly predicted land condition class on &gt;40% of sites. While the best models predicted condition correctly at &gt;60% of A and D condition sites, condition at sites in B and C condition sites was poorly predicted. Several factors limit how well ground cover levels predict land condition. The main challenge is modelling a multidimensional value (grazing land condition) with a unidimensional ground cover measurement. We suggest that better land condition models require a range of predictors to address this multidimensionality but cover indices can make a substantial contribution in this context.

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.

Expansion of Vertebrate Pest Exclusion Fencing and Its Potential Benefits for Threatened Fauna Recovery in Australia

The global effort to conserve threatened species relies heavily on our ability to separate these species from the processes that threaten them, and a common tool used for this purpose is exclusion fencing. In Australia, pest animal exclusion fencing has been repeatedly used on conservation land on a small scale to successfully exclude introduced predators and competitors from threatened native fauna populations. However, in recent years, "cluster fencing" on agricultural land has re-emerged on a large scale and is used by livestock producers seeking to reduce predation losses by dingoes (Canis familiaris) and manage total grazing pressure from native and introduced herbivores, including red kangaroos (Osphranter rufus). Given that the primary threats to at-risk native fauna are also predation and overgrazing, there may be potential for cluster fencing on livestock land to achieve additional fauna conservation benefits. Understanding the amount, location and potential conservation value of cluster fenced livestock land is critical for determining how these areas might contribute to broader threatened fauna recovery goals. Drawing from publicly available databases maintained by the Australian Government, we assessed the spatial overlap of threatened species' distributions with 105 cluster fences erected in Queensland since 2013, which cover 65,901 km² of land. These cluster fenced areas represent 18 biogeographic subregions and may contain 28 extant threatened mammals, birds and reptiles including 18 vulnerable species, 7 endangered species and 3 critically endangered species. An average of nine threatened species or their habitats were identified per cluster, and over three quarters (78.6%) of these species face at least one threat that is being mitigated within clusters. The true status of threatened and pest species within clusters is largely unknown or unrecorded in most cases, but some examples of pest eradication and threatened species recovery are already emerging. Given the vast size of the cluster fenced estate, the many different biomes and species that it represents and the nature of the threats being removed within these fenced areas, we contend that agricultural cluster fencing may offer an unprecedented opportunity to advance threatened fauna conservation goals for some species at scales previously thought impossible and should be a research priority for threatened species managers.

Impacts of exclusion fencing on target and non-target fauna: a global review

Exclusion fencing is a common tool used to mitigate a variety of unwanted economic losses caused by problematic wildlife. While the potential for agricultural, ecological and economic benefits of pest animal exclusion are often apparent, what is less clear are the costs and benefits to sympatric non-target wildlife. This review examines the use of exclusion fencing in a variety of situations around the world to elucidate the potential outcomes of such fencing for wildlife and apply this knowledge to the recent uptake of exclusion fencing on livestock properties in the Australian rangelands. In Australia, exclusion fences are used to eliminate dingo (Canis familiaris dingo) predation on livestock, prevent crop-raiding by emus (Dromaius novaehollandiae), and enable greater control over total grazing pressure through the reduction of macropods (Macropodidae) and feral goats (Capra hircus). A total of 208 journal articles were examined for location, a broad grouping of fence type, and the reported effects the fence was having on the study species. We found 51% of the literature solely discusses intended fencing effects, 42% discusses unintended effects, and only 7% considers both. Africa has the highest proportion of unintended effects literature (52.0%) and Australia has the largest proportion of literature on intended effects (34.2%). We highlight the potential for exclusion fencing to have positive effects on some species and negative effects on others (such as predator exclusion fencing posing a barrier to migration of other species), which remain largely unaddressed in current exclusion fencing systems. From this review we were able to identify where and how mitigation strategies have been successfully used in the past. Harnessing the potential benefits of exclusion fencing while avoiding the otherwise likely costs to both target and non-target species will require more careful consideration than this issue has previously been afforded.

Carbon farming for resilient rangelands: people, paddocks and policy

Carbon farming is a new land use option over extensive areas of the Australian rangelands. This land use change has been promoted by government incentives to mitigate climate change, with most of Australia’s land sector abatement to date being delivered in rangelands. Aside from these mitigation benefits, carbon farming has also demonstrated potential co-benefits that enhance socio-ecological resilience by diversifying land uses and income streams, providing opportunities for sustainable land management to enhance soil and vegetation and creating opportunities for self-organisation and collaboration. However, factors such as policy uncertainty, perceived loss of future land use flexibility and the potential for carbon farming eligibility to create social divisions may negatively affect resilience. In this paper we weigh up these risks, opportunities and co-benefits and propose indicators for measuring the impact of carbon farming on the resilience of rangeland systems. A set of land policy principles for enhancing resilience through carbon farming are also identified.

Balancing stakeholder interests in kangaroo management – historical perspectives and future prospects

Kangaroos are commercially harvested in five mainland states of Australia, with the harvest regulated by state government wildlife management agencies and overseen by the Commonwealth government. Non-commercial culling is permitted, and although most kangaroos have traditionally been taken by the commercial kangaroo harvesting industry, the proportion taken non-commercially has increased in recent years. Management plans that guide the regulation of the harvest support the management objectives of wildlife management agencies and the kangaroo industry, but the plans do not successfully address the objectives of other stakeholders including pastoralists and animal protection groups, which focus on minimising the grazing impacts of kangaroos and animal welfare issues respectively. We reviewed the objectives outlined in the management plans for kangaroos in the Australian rangelands and examined alternative systems for managing natural resources to identify if improvements to management could be made. Current management plans for kangaroos principally use fixed harvest rates that are responsive only to the state of the kangaroo population and not to changes in the environments in which kangaroos live. This type of management is reactive, and opportunities for improving management of the environment are limited. A viable alternative is active adaptive management which focuses on explicit measurement of the response of the natural system to management actions and use of this information to modify interventions to better meet management objectives. Active adaptive management is appropriate when management actions can strongly influence system state but the impacts of management are uncertain. We argue that the management of kangaroos and the environments in which they live would benefit from the adoption of an active adaptive management approach by wildlife management agencies.

Prospects for ecologically and socially sustainable management of total grazing pressure in the southern rangelands of Australia

Numerous large herbivore species, both native and exotic, share the southern Australian rangelands with domestic livestock, which often account for only about half of the total grazing pressure. Although each presents its individual challenge to landholders, the management of kangaroos is a key component of ecologically sustainable management of the region because (a) they represent a significant component of the non-domestic grazing pressure, particularly in areas from which dingos and wild dogs have been (partially) removed; (b) commercial harvesting, the means of control that has the highest social acceptability, has been rendered ineffective by the actions of activist groups and market closure due to food safety concerns; (c) the task is largely beyond the capacity of individual landholders; and (d) the same constraints do not apply to other non-domestic components of total grazing pressure. Management of total grazing pressure, and particularly kangaroos, currently represents a case of market failure because the level of management that can be expected of landholders is not consistent with public expectations for resource conservation and animal welfare. Several avenues are available by which kangaroo management could be advanced to achieve both public and private benefits. These include adoption of an active, adaptive management approach to the kangaroo population, establishment of arrangements that will shift the general perception of kangaroos from pest to resource, development of an appropriate incentive framework to achieve desirable landscape outcomes, and continued evaluation of the benefits and costs of cluster fencing. These initiatives require both a greater commitment from governments to address the market failure and a proactive stance by industry to engage stakeholders, self-regulate, and objectively demonstrate environmental and animal welfare credentials.