Description:
In the file sharing ecosystem, One-Click File Hosting Services (FHS) such as Rapidgator and Uploaded, the previously Rapidshare and Megaupload, provide a platform for users to share copyrighted content. We present a publisher-side analysis of FHS file sharing dynamics through data collected from active measurement by crawling Warez-BB. The website is essentially a forum where publishers can share links to content they have uploaded on file hosting services. Consumers can use the website to gain access to content shared on the website, often free of charge. We primarily analyse various characteristics of file sharing with respect to view count as the evaluation metric.
Description:
Four decades have passed since the introduction of Conservation Agriculture research and development. We also mark forty years since the introduction of the Declaration of Alma-Ata at the International Conference on Primary Health Care, Alma-Ata, Kazakhstan, 6–12 September 1978. Furthermore, of significance to the future development of sustainable agriculture practices and healthy communities, is the introduction of the United Nations Sustainable Development Goals in January 2016. These follow on from the Millennium Development goals that will guide the United Nations Development Program policy and development unti l 2030. An Australian case study on Conservation Agriculture is presented examining the relationship between Conservation Agriculture, health and wellbeing and sustainable development. It is argued that an ecosystems approach is useful for strategic sustainable development to understand the connectedness and inter-relationship between climate change agricultural practices, sense of place, identity, health and wellbeing. Community development processes can assist to build strong communities through collaboration between farmers, farmer organizations, local experts, and national and regional public and private institutions.
Description:
Four decades have passed since the introduction of Conservation Agriculture research and development. We also mark forty years since the introduction of the Declaration of Alma-Ata at the International Conference on Primary Health Care, Alma-Ata, Kazakhstan, 6–12 September 1978. Furthermore, of significance to the future development of sustainable agriculture practices and healthy communities, is the introduction of the United Nations Sustainable Development Goals in January 2016. These follow on from the Millennium Development goals that will guide the United Nations Development Program policy and development unti l 2030. An Australian case study on Conservation Agriculture is presented examining the relationship between Conservation Agriculture, health and wellbeing and sustainable development. It is argued that an ecosystems approach is useful for strategic sustainable development to understand the connectedness and inter-relationship between climate change agricultural practices, sense of place, identity, health and wellbeing. Community development processes can assist to build strong communities through collaboration between farmers, farmer organizations, local experts, and national and regional public and private institutions.
Description:
Summary Trophic cascade theory predicts that apex predators structure ecosystems by regulating mesopredator and herbivore abundance and behaviour. Studies on trophic cascades have typically focused on short linear chains of species interactions. A framework that integrates more realistic and complex interactions is needed to make broader predictions on ecosystem structuring. Network analysis is used to study food webs and other types of species interaction networks. These often comprise large numbers of species but rarely account for multiple interaction types and strengths. Here, we develop an intermediate complexity theoretical framework that allows specification of multiple interaction types and strengths for the study of trophic cascades. This ecological network is designed to suit data typically derived from field‐based studies. The trophic cascade network contains fewer nodes than food webs, but provides semi‐weighted directional links that enable different types of interactions to be included in a single model. We use this trophic cascade network model to explore how an apex predator shapes ecosystem structure in an Australian arid ecosystem. We compared two networks that contrasted in the dominance of an apex predator, the dingo (Canis dingo), using published results ranking the direction and strength of key interactions. Nodes and links interacted dynamically to shape these networks. We examined how changes to an apex predator population affect ecosystem structure through their direct and indirect influences on different components of this ecological community. Under strong apex predator influence, the network structure was denser and more complex, even and top‐down driven and dingo predation and soil commensalism formed denser interactive modules. Under weak apex predator influence (e.g. reflecting predator control), the resulting network structure was frayed, with mesopredator predation and grazing forming modules. Our study demonstrates that networks of intermediate complexity can provide a powerful tool for elucidating potential ecosystem‐wide effects of apex predators and predicting the consequences of management interventions such as predator control. Integrating trophic cascades, with their array of complex interactions, with the three‐dimensional structure of ecological networks, has the potential to reveal ‘ecological architecture’ that neither captures on its own.
Description:
Biological invasions are one of the major threats to Antarctic native biodiversity and to ecosystems integrity. Regional environmental change and increasing human activity in Maritime Antarctica facilitates the introduction, establishment and colonisation of an increasing number of non-indigenous species. Systematic monitoring is an essential tool for the early detection of the arrival of non-indigenous arthropods. In this study, we compiled the results of a long-term monitoring effort from 2011 to 2017 to survey non-native collembolan species on Deception Island, a highly visited terrestrial site in South Shetland Islands (Maritime Antarctica). Results include the first record of Ceratophysella succinea (Gisin) (Hypogastruridae) in Antarctica. Moreover, the global dataset indicates that the total number and the list of cumulatively occurrence localities for non-native species observed on the island has increased over this monitoring period. This suggests that repeated monitoring is advisable to characterise the full extent of microarthropod introductions into a high biosecurity risk area and improve the effectiveness of surveillance efforts.
Description:
Although only representing 0.05% of global freshwater, or 0.001% of all global water, soil water supports all terrestrial biological life. Soil moisture behaviour in most models is constrained by hydraulic parameters that do not change. Here we argue that biological feedbacks from plants, macro-fauna and the microbiome influence soil structure, and thus the soil hydraulic parameters and the soil water content signals we observe. Incorporating biological feedbacks into soil hydrological models is therefore important for understanding environmental change and its impacts on ecosystems. We anticipate that environmental change will accelerate and modify soil hydraulic function. Increasingly, we understand the vital role that soil moisture exerts on the carbon cycle and other environmental threats such as heatwaves, droughts and floods, wildfires, regional precipitation patterns, disease regulation and infrastructure stability, in addition to agricultural production. Biological feedbacks may result in changes to soil hydraulic function that could be irreversible, resulting in alternative stable states (ASS) of soil moisture. To explore this, we need models that consider all the major feedbacks between soil properties and soil-plant-faunal-microbial-atmospheric processes, which is something we currently do not have. Therefore, a new direction is required to incorporate a dynamic description of soil structure and hydraulic property evolution into soil-plant-atmosphere, or land surface, models that consider feedbacks from land use and climate drivers of change, so as to better model ecosystem dynamics.
Description:
The concepts of ecosystem regime shifts, thresholds and alternative or multiple stable states are used extensively in the ecological and environmental management literature. When applied to aquatic ecosystems, these terms are used inconsistently reflecting differing levels of supporting evidence among ecosystem types. Although many aquatic ecosystems around the world have become degraded, the magnitude and causes of changes, relative to the range of historical variability, are poorly known. A working group supported by the Australian Centre for Ecological Analysis and Synthesis (ACEAS) reviewed 135 papers on freshwater ecosystems to assess the evidence for pressure-induced non-linear changes in freshwater ecosystems; these papers used terms indicating sudden and non-linear change in their titles and key words, and so was a positively biased sample. We scrutinized papers for study context and methods, ecosystem characteristics and focus, types of pressures and ecological responses considered, and the type of change reported (i.e., gradual, non-linear, hysteretic or irreversible change). There was little empirical evidence for regime shifts and changes between multiple or alternative stable states in these studies although some shifts between turbid phytoplankton-dominated states and clear-water, macrophyte-dominated states were reported in shallow lakes in temperate climates. We found limited understanding of the subtleties of the relevant theoretical concepts and encountered few mechanistic studies that investigated or identified cause-and-effect relationships between ecological responses and nominal pressures. Our results mirror those of reviews for estuarine, nearshore and marine aquatic ecosystems, demonstrating that although the concepts of regime shifts and alternative stable states have become prominent in the scientific and management literature, their empirical underpinning is weak outside of a specific environmental setting. The application of these concepts in future research and management applications should include evidence on the mechanistic links between pressures and consequent ecological change. Explicit consideration should also be given to whether observed temporal dynamics represent variation along a continuum rather than categorically different states.
Description:
Worldwide, estuarine research involving a long-term perspective to aid conservation and management has lagged behind terrestrial and lake environment research. Consequently, despite the obvious importance of estuaries, this means we have limited detailed knowledge of how they function or the ranges of natural variability they experience and how humans have, and will interact with these influences. Gaining a clear understanding using a long-term perspective is crucial if we are to maintain and restore the integrity of estuarine environments. While paleoecological studies in the ocean and lakes are well-established science, applications of paleoecological techniques in estuarine environments remains largely novel and in some cases problematic. In recent years estuarine paleoecological research has rapidly developed and an increasing range of technological applications is improving our understanding of the dynamic and variable nature of estuaries. The purpose of this book is to briefly describe estuarine form and function and to demonstrate the application of different paleoecological approaches used in estuaries that develop our understanding of their response to natural and human influences. Chapters 1–4 provide the framework for this book. They describe the characteristics of estuaries, important factors influencing them and introduce paleoecology as a useful tool for estuarine management. The following chapters (5–7) outline the essential steps required for undertaking a paleoecological study, in particular with regard to site selection, core extraction and chronological techniques, followed by the range of indicators that can be used. They are divided into geochemical proxies and pollutants (8–10) and biological proxies (11–18). The book concludes with a series of case studies (19–24): the first study focuses on sea level changes, while the rest present research from major estuaries (sensu lato) worldwide, to demonstrate how paleoecological studies can be used to address key questions, and to sustainably manage these important coastal environments in the future.
Description:
Concerning declines in insect populations have been reported from Europe and the United States, yet there are gaps in our knowledge of the drivers of insect trends and their distribution across the world. We report on our analysis of a spatially extensive, 14‐year study of ground‐dwelling beetles in four natural forest biomes spanning Japan's entire latitudinal range (3000 km). Beetle species richness, abundance and biomass declined in evergreen coniferous forests but increased in broadleaf‐coniferous mixed forests. Further, beetles in evergreen coniferous forests responded negatively to increased temperature and precipitation anomalies, which have both risen over the study's timespan. These significant changes parallel reports of climate‐driven changes in forest tree species, providing further evidence that climate change is altering forest ecosystems fundamentally. Given the enormous biodiversity and ecosystem services that forests support globally, the implications for biodiversity change resulting from climate change could be profound. With recent concerns about catastrophic insect declines in the US and Europe, research that provides evidence for insect trends in other regions and in forest ecosystems is crucial. We report on data of forest beetles collected over a 14‐year period in forest plots across the whole latitudinal range of Japan (3000 km). Using these data, we show declines in evergreen coniferous forests accompanied with community changes in other forest biomes.
Description:
Plant invasions of natural ecosystems are one of the major threats to the conservation of biological diversity across nearly all biogeographical regions in the world. This thesis focuses on Galenia pubescens (Carpet weed) as a case study of possible approaches to the potential management of environmental weed species. G. pubescens is a woody prostrate perennial plant that is becoming a serious threat to Australian temperate grasslands, surrounding agricultural areas and conservation reserves. It is indigenous to South Africa and was first recorded in Australia in the early 1900s, and it is an aggressive competitor against native species. It is difficult to control, and little information exists about its effects on natural ecosystems, and aspects of its biology and ecology. This study has investigated some important ecological characteristics of G. pubescens’ seeds and has experimented with different management strategies in combination with chemical control. It has also considered the potential for the expansion of the distribution of this species across suitable habitat in Australia under predicted elevated CO2 and drought conditions. Seeds of G. pubescens are shown to be able to germinate over a broad range of temperatures, but short bursts (5 minutes) of high temperatures (80oC to 120oC replicating possible exposures to a fire) reduced seed germination. Seed germination was positively favored by light and declined rapidly in darkness, decreasing by > 80% at a depth of only 0.5 cm in soil. This suggests that fire regimes might be useful in removing mature plants and controlling seed numbers on the surface, and that subsequent native seeding of undisturbed areas may assist in the long-term management of this noxious weed. A trial was conducted to determine the effect of treatment with a plant essential oil (pine oil) to limit the seed germination and seedling emergence of G. pubescens. This trial showed that the effects of pine oil application were significant (P<0.05). Germination was completely inhibited by application of pine oil at 5% or higher concentrations directly to seeds, and seedling emergence was reduced by between 90 and 100% in pot trials. These outcomes demonstrate the potential viability of pine oil as a long-term control option for this species. In field-based experiments, control strategies including herbicide control with glyphosate, organic herbicide control with pine oil, the application of mulch, and the addition of native seeds to the available seedbank (and all possible combinations of these techniques), were tested. The study showed that one single treatment of a G. pubescens infestation without undertaking a secondary treatment is insufficient to control the G. pubescens infestation or to encourage native regeneration, but that a combined strategy, employing all the aforementioned techniques, is more effective. It is however suggested that full regeneration of the area may not be possible unless further restoration programs are instituted after the cycle of G. pubescens’ treatment has been completed. The thesis also assessed the control effects of chemical control combined with a prescribed spring burning. Assessment of the resulting aboveground vegetation of G. pubescens has shown that a combination of chemical control and late-spring burning can reduce the cover of non-native species such as G. pubescens, suggesting that this could be a useful tool in their management. Finally, this study has supported the view that the growth of G. pubescens will be significantly enhanced in a future climate with an enriched atmospheric CO2 concentration. These climatic changes will have important implications for management of this noxious weed in the future.
Description:
Plant invasions of natural ecosystems are one of the major threats to the conservation of biological diversity across nearly all biogeographical regions in the world. This thesis focuses on Galenia pubescens (Carpet weed) as a case study of possible approaches to the potential management of environmental weed species. G. pubescens is a woody prostrate perennial plant that is becoming a serious threat to Australian temperate grasslands, surrounding agricultural areas and conservation reserves. It is indigenous to South Africa and was first recorded in Australia in the early 1900s, and it is an aggressive competitor against native species. It is difficult to control, and little information exists about its effects on natural ecosystems, and aspects of its biology and ecology. This study has investigated some important ecological characteristics of G. pubescens’ seeds and has experimented with different management strategies in combination with chemical control. It has also considered the potential for the expansion of the distribution of this species across suitable habitat in Australia under predicted elevated CO2 and drought conditions. Seeds of G. pubescens are shown to be able to germinate over a broad range of temperatures, but short bursts (5 minutes) of high temperatures (80oC to 120oC replicating possible exposures to a fire) reduced seed germination. Seed germination was positively favored by light and declined rapidly in darkness, decreasing by > 80% at a depth of only 0.5 cm in soil. This suggests that fire regimes might be useful in removing mature plants and controlling seed numbers on the surface, and that subsequent native seeding of undisturbed areas may assist in the long-term management of this noxious weed. A trial was conducted to determine the effect of treatment with a plant essential oil (pine oil) to limit the seed germination and seedling emergence of G. pubescens. This trial showed that the effects of pine oil application were significant (P<0.05). Germination was completely inhibited by application of pine oil at 5% or higher concentrations directly to seeds, and seedling emergence was reduced by between 90 and 100% in pot trials. These outcomes demonstrate the potential viability of pine oil as a long-term control option for this species. In field-based experiments, control strategies including herbicide control with glyphosate, organic herbicide control with pine oil, the application of mulch, and the addition of native seeds to the available seedbank (and all possible combinations of these techniques), were tested. The study showed that one single treatment of a G. pubescens infestation without undertaking a secondary treatment is insufficient to control the G. pubescens infestation or to encourage native regeneration, but that a combined strategy, employing all the aforementioned techniques, is more effective. It is however suggested that full regeneration of the area may not be possible unless further restoration programs are instituted after the cycle of G. pubescens’ treatment has been completed. The thesis also assessed the control effects of chemical control combined with a prescribed spring burning. Assessment of the resulting aboveground vegetation of G. pubescens has shown that a combination of chemical control and late-spring burning can reduce the cover of non-native species such as G. pubescens, suggesting that this could be a useful tool in their management. Finally, this study has supported the view that the growth of G. pubescens will be significantly enhanced in a future climate with an enriched atmospheric CO2 concentration. These climatic changes will have important implications for management of this noxious weed in the future.
Description:
Microplastics, as an emerging contaminant, have been shown to threaten the sustainability of ecosystems, and there is also concern about human exposure, as microplastic particles tend to bioaccumulate and biomagnify through the food chain. While microplastics in marine environments have been extensively studied, research on microplastics in terrestrial ecosystems is just starting to gain momentum. In this paper, we used scientometric analysis to understand the current status of microplastic research in terrestrial systems. The global scientific literature on microplastics in terrestrial ecosystems, based on data from the Web of Science between 1986 and 2020, was explored with the VOSviewer scientometric software. Co-occurrence visualization maps and citation analysis were used to identify the relationship among keywords, authors, organizations, countries, and journals focusing on the issues of terrestrial microplastics. The results show that research on microplastics in terrestrial systems just started in the past few years but is increasing rapidly. Science of the Total Environment ranks first among the journals publishing papers on terrestrial microplastics. In addition, we also highlighted the desire to establish standards/protocols for extracting and quantifying microplastics in soils. Future studies are recommended to fill the knowledge gaps on the abundance, distribution, ecological and economic effects, and toxicity of microplastics.
Description:
The aim of this edited volume is to introduce the scientific community to paleoenvironmental studies of estuaries, to highlight the types of information that can be obtained from such studies, and to promote the use of paleoenvironmental studies in estuarine management. Readers will learn about the the application of different paleoecological approaches used in estuaries that develop our understanding of their response to natural and human influences. Particular attention is given to the essential steps required for undertaking a paleoecological study, in particular with regard to site selection, core extraction and chronological techniques, followed by the range of indicators that can be used. A series of case studies are discussed in the book to demonstrate how paleoecological studies can be used to address key questions, and to sustainably manage these important coastal environments in the future. This book will appeal to professional scientists interested in estuarine studies and/or paleoenvironmental research, as well as estuarine managers who are interested in the incorporation of paleoenvironmental research into their management programs.