scholarly journals Twinkling lights or turning down the dimmer switch? Are there two patterns of extinction debt in fragmented landscapes?

2011 ◽  
Vol 17 (4) ◽  
pp. 303 ◽  
Author(s):  
Hugh A Ford
Keyword(s):  
Bird Species ◽  
Dispersal Ability ◽  
Extinction Debt ◽  
Woodland Birds ◽  
Fragmented Landscapes ◽  
The Matrix ◽  
Long Time ◽  
The Rich ◽  
Key Resources

The decline and local extinction of many woodland birds across southern Australia is continuing and seems likely to continue for a long time even though broad-scale clearing has ceased in many regions. The small proportion of remaining vegetation and its fragmented and degraded nature will probably mean that a long-term extinction debt will have to be paid. For some species this will be through the process of successive extinctions of sub-populations and lack of recolonization due to poor dispersal ability, leading to ultimate extinction of the metapopulation. However, many bird species in Australia travel locally and regionally to exploit resources that vary in time and space (rich-patch nomads), and appear to be quite capable of dispersing in fragmented landscapes. Many of these too are declining and we need to understand the processes involved in their decline. Making the matrix more hospitable may reverse the declines of the poor dispersers. However, a different approach may be needed to assist the rich-patch nomads, such as re-establishing key resources. This will involve a better understanding of their natural history.

scholarly journals Evaluating the role of contracting and expanding rainforest in initiating cycles of speciation across the Isthmus of Panama

2012 ◽  
Vol 279 (1742) ◽  
pp. 3520-3526 ◽  
Author(s):  
Brian Tilston Smith ◽  
Amei Amei ◽  
John Klicka
Keyword(s):  
Bird Species ◽  
Tropical Regions ◽  
Isthmus Of Panama ◽  
Species Pairs ◽  
The Matrix ◽  
High Species Richness ◽  
The Rich ◽  
The Tropics ◽  
The Impact

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.

scholarly journals Beyond pattern to process: current themes and future directions for the conservation of woodland birds through restoration plantings

2018 ◽  
Vol 45 (6) ◽  
pp. 473 ◽  
Author(s):  
Donna J. Belder ◽  
Jennifer C. Pierson ◽  
Karen Ikin ◽  
David B. Lindenmayer
Keyword(s):  
Habitat Loss ◽  
Resource Availability ◽  
Bird Species ◽  
Agricultural Landscapes ◽  
Conservation Strategies ◽  
Future Research ◽  
Knowledge Gaps ◽  
Woodland Birds ◽  
Conservation Concern

Habitat loss as a result of land conversion for agriculture is a leading cause of global biodiversity loss and altered ecosystem processes. Restoration plantings are an increasingly common strategy to address habitat loss in fragmented agricultural landscapes. However, the capacity of restoration plantings to support reproducing populations of native plants and animals is rarely measured or monitored. This review focuses on avifaunal response to revegetation in Australian temperate woodlands, one of the world’s most heavily altered biomes. Woodland birds are a species assemblage of conservation concern, but only limited research to date has gone beyond pattern data and occupancy trends to examine whether they persist and breed in restoration plantings. Moreover, habitat quality and resource availability, including food, nesting sites and adequate protection from predation, remain largely unquantified. Several studies have found that some bird species, including species of conservation concern, will preferentially occupy restoration plantings relative to remnant woodland patches. However, detailed empirical research to verify long-term population growth, colonisation and extinction dynamics is lacking. If restoration plantings are preferentially occupied but fail to provide sufficient quality habitat for woodland birds to form breeding populations, they may act as ecological traps, exacerbating population declines. Monitoring breeding success and site fidelity are under-utilised pathways to understanding which, if any, bird species are being supported by restoration plantings in the long term. There has been limited research on these topics internationally, and almost none in Australian temperate woodland systems. Key knowledge gaps centre on provision of food resources, formation of optimal foraging patterns, nest-predation levels and the prevalence of primary predators, the role of brood parasitism, and the effects of patch size and isolation on resource availability and population dynamics in a restoration context. To ensure that restoration plantings benefit woodland birds and are cost-effective as conservation strategies, the knowledge gaps identified by this review should be investigated as priorities in future research.

Impact and response: a review of the effects of fire on the Australian avifauna

1997 ◽  
Vol 3 (3) ◽  
pp. 183 ◽  
Author(s):  
J. C. Z. Woinarski ◽  
H. F. Recher
Keyword(s):  
Bird Species ◽  
Fire Regimes ◽  
Fire Intensity ◽  
Dispersal Ability ◽  
Sufficient Information ◽  
Avian Communities ◽  
Australian Continent ◽  
The Impact ◽  
Long Term Studies

The literature concerning the impact of fire on avian communities and the response of birds to fire is reviewed for the Australian continent. There are few detailed long-term studies of the effects of fire on avian communities, but there is sufficient information on fire effects from a broad cross-section of Australian habitats to identify patterns of response to individual fires and to predict likely long-term effects. Some birds respond immediately to fire, taking advantage of temporarily increased availability of food. These birds include predators that are attracted to fires to feed on exposed, disoriented and fire-killed prey and seed-eaters that congregate in burnt habitats to feed on seeds released by the fire or on the seeds of rapidly maturing post-fire ephemerals. At least in eucalypt forests, there is an increase of arthropod abundance on the rapidly regenerating vegetation that may lead to increased abundances of some bird species. Depending on the severity of the fire and the amount of vegetation killed, most avian communities recover rapidly following single fires regardless of fire intensity. However, such fires may pose a significant threat to species with a restricted distribution, limited reproductive potential, poor dispersal ability and/or narrow habitat requirements. Birds persisting in fragmented habitats are particularly at risk. However, of greatest significance as a threatening process to avian communities are increases in fire frequency. Of the threatened species in Australia whose relationships with fire have been comparatively well-documented, almost all show a clear preference for less frequent fires. Detrimental fire regimes contributed to the extinction of two of the three bird species and three of the four subspecies which have disappeared from Australia since European colonization. Inappropriate fire management is now a factor in the threatened status of at least 51 nationally recognized threatened Australian bird taxa. In many environments (notably heath and mallee), inappropriate fire regimes are the main threat to declining bird species. In temperate eucalypt forest and woodland, as well as in heathlands, control burning is widely used to reduce the threat of wildfire. While, in general, the immediate impact of controlled burns is less than that of wildfire, the frequency of these fires can lead to floristic and structural changes in the vegetation. Although not well-documented, these vegetative changes adversely affect the avifauna. In Australia, the most detailed long-term studies suggest that frequent, low-intensity fires may lead to the decline and loss of some species which are now perceived as common and little affected by mild fires.

scholarly journals Stability of African Swine Fever Virus in Carcasses of Domestic Pigs and Wild Boar Experimentally Infected with the ASFV “Estonia 2014” Isolate

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1118 ◽  
Author(s):  
Melina Fischer ◽  
Jane Hühr ◽  
Sandra Blome ◽  
Franz J. Conraths ◽  
Carolina Probst
Keyword(s):  
Wild Boar ◽  
Infectious Virus ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Domestic Pigs ◽  
Source Of Infection ◽  
The Matrix ◽  
Different Temperatures ◽  
Long Time

Europe is currently experiencing a long-lasting African swine fever (ASF) epidemic, both in domestic pigs and wild boar. There is great concern that carcasses of infected wild boar may act as long-term virus reservoirs in the environment. We evaluated the tenacity of ASF virus (ASFV) in tissues and body fluids from experimentally infected domestic pigs and wild boar, which were stored on different matrices and at different temperatures. Samples were analysed at regular intervals for viral genome and infectious virus. ASFV was most stable in spleen or muscles stored at −20 °C and in blood stored at 4 °C. In bones stored at −20 °C, infectious virus was detected for up to three months, and at 4 °C for up to one month, while at room temperature (RT), no infectious virus could be recovered after one week. Skin stored at −20 °C, 4 °C and RT remained infectious for up to three, six and three months, respectively. In urine and faeces, no infectious virus was recovered after one week, irrespective of the matrix. In conclusion, tissues and organs from decomposing carcasses that persist in the environment for a long time can be a source of infection for several months, especially at low temperatures.

Enhancing the power generation of Rhodopseudomonas palustris-based MFC

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1261-1268
Author(s):  
Shu Otani ◽  
Dang-Trang Nguyen ◽  
Kozo Taguchi
Keyword(s):  
Activated Carbon ◽  
Rhodopseudomonas Palustris ◽  
Ozone Treatment ◽  
Maximum Power Density ◽  
On Demand ◽  
Long Time ◽  
Dry Conditions ◽  
Carbon Sheet ◽  
Uv Ozone

In this study, a portable and disposable paper-based microbial fuel cell (MFC) was fabricated. The MFC was powered by Rhodopseudomonas palustris bacteria (R. palustris). An activated carbon sheet-based anode pre-loaded organic matter (starch) and R. palustris was used. By using starch in the anode, R. palustris-loaded on the anode could be preserved for a long time in dry conditions. The MFC could generate electricity on-demand activated by adding water to the anode. The activated carbon sheet anode was treated by UV-ozone treatment to remove impurities and to improve its hydrophilicity before being loaded with R. palustris. The developed MFC could generate the maximum power density of 0.9 μW/cm2 and could be preserved for long-term usage with little performance degradation (10% after four weeks).

Globalisation and Equity Issues in Post-socialist Transition Economies

2004 ◽  
Vol 54 (3) ◽  
pp. 273-296
Author(s):  
G. W. Kolodko
Keyword(s):  
Transition Economies ◽  
World Market ◽  
Early Years ◽  
Standard Of Living ◽  
Social Constraints ◽  
Significant Shift ◽  
Equity Issues ◽  
Goods And Services ◽  
The Rich

Equity issues in policymaking are difficult to resolve because they are linked not only to the economic situation but also to social constraints and political conflicts within a country. This is even more true in the case of post-socialist economies during their transition to a market system in the era of globalisation. The historical and irreversible process of liberalisation and integration of capital, goods and services, and labour markets into one world market, as well as the gradual construction of new institutions and the process of privatisation cause a significant shift in the income pattern of post-socialist emerging markets. Contrary to expectations, inequality increases affecting the standard of living and long-term growth. While globalisation contributes to the long-term acceleration of economic growth and offers a chance for many countries and regions to catch up with more advanced economies, it results in growing inequality both between the countries and within them. On average, the standard of living increases, but so does the gap between the rich and the poor. Therefore, equality issues should always be of concern to policymakers, especially in the early years of the change of regime in post-socialist transition economies.

Charlemagne’s Health in ‘Old Age’: Did It Affect Carolingian Military Strategy?

Mediaevistik ◽  
2020 ◽  
Vol 32 (1) ◽  
pp. 11-53
Author(s):  
Bernard S. Bachrach
Keyword(s):  
Old Age ◽  
The Political ◽  
Military Strategy ◽  
The West ◽  
Long Time

During the first thirty-three years of his reign as king of the Franks, i.e., prior to his coronation as emperor on Christmas day 800, Charlemagne, scholars generally agree, pursued a successful long-term offensive and expansionist strategy. This strategy was aimed at conquering large swaths of erstwhile imperial territory in the west and bringing under Carolingian rule a wide variety of peoples, who either themselves or their regional predecessors previously had not been subject to Frankish regnum.1 For a very long time, scholars took the position that Charlemagne continued to pursue this expansionist strategy throughout the imperial years, i.e., from his coronation on Christmas Day 800 until his final illness in later January 814. For example, Louis Halphen observed: “comme empereur, Charles poursuit, sans plus, l’oeuvre entamée avant l’an 800.”2 F. L. Ganshof, who also wrote several studies treating Charlemagne’s army, was in lock step with Halphen and observed: “As emperor, Charlemagne pursued the political and military course he had been following before 25 December 800.”3

The Spread of Pollutants from Harbour Sludge Depots

1984 ◽  
Vol 16 (3-4) ◽  
pp. 623-633
Author(s):  
M Loxham ◽  
F Weststrate
Keyword(s):  
Time Scales ◽  
Molecular Diffusion ◽  
Near Field ◽  
Parameter Analysis ◽  
Migration Patterns ◽  
Long Time ◽  
Dilution Effects ◽  
Short Time ◽  
Harbour Sludge

It is generally agreed that both the landfill option, or the civil techniques option for the final disposal of contaminated harbour sludge involves the isolation of the sludge from the environment. For short time scales, engineered barriers such as a bentonite screen, plastic sheets, pumping strategies etc. can be used. However for long time scales the effectiveness of such measures cannot be counted upon. It is thus necessary to be able to predict the long term environmenttal spread of contaminants from a mature landfill. A model is presented that considers diffusion and adsorption in the landfill site and convection and adsorption in the underlaying aquifer. From a parameter analysis starting form practical values it is shown that the adsorption behaviour and the molecular diffusion coefficient of the sludge, are the key parameters involved in the near field. The dilution effects of the far field migration patterns are also illustrated.

The Many Faces of Socioeconomic Change

2017 ◽  
Author(s):  
John Toye
Keyword(s):  
Socioeconomic Development ◽  
Adam Smith ◽  
First Century ◽  
Social Progress ◽  
Long Time ◽  
The Face ◽  
Scientific Expertise ◽  
The Many ◽  
Century Development

This book provides a survey of different ways in which economic sociocultural and political aspects of human progress have been studied since the time of Adam Smith. Inevitably, over such a long time span, it has been necessary to concentrate on highlighting the most significant contributions, rather than attempting an exhaustive treatment. The aim has been to bring into focus an outline of the main long-term changes in the way that socioeconomic development has been envisaged. The argument presented is that the idea of socioeconomic development emerged with the creation of grand evolutionary sequences of social progress that were the products of Enlightenment and mid-Victorian thinkers. By the middle of the twentieth century, when interest in the accelerating development gave the topic a new impetus, its scope narrowed to a set of economically based strategies. After 1960, however, faith in such strategies began to wane, in the face of indifferent results and general faltering of confidence in economists’ boasts of scientific expertise. In the twenty-first century, development research is being pursued using a research method that generates disconnected results. As a result, it seems unlikely that any grand narrative will be created in the future and that neo-liberalism will be the last of this particular kind of socioeconomic theory.

scholarly journals Domain randomization-enhanced deep learning models for bird detection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Mao ◽  
Jun Kang Chow ◽  
Pin Siang Tan ◽  
Kuan-fu Liu ◽  
Jimmy Wu ◽  
...  
Keyword(s):  
Deep Learning ◽  
Continuous Monitoring ◽  
Bird Species ◽  
Training Data ◽  
Learning Models ◽  
Fine Grained ◽  
Bird Detection ◽  
Relationship Of ◽  
The Relationship

AbstractAutomatic bird detection in ornithological analyses is limited by the accuracy of existing models, due to the lack of training data and the difficulties in extracting the fine-grained features required to distinguish bird species. Here we apply the domain randomization strategy to enhance the accuracy of the deep learning models in bird detection. Trained with virtual birds of sufficient variations in different environments, the model tends to focus on the fine-grained features of birds and achieves higher accuracies. Based on the 100 terabytes of 2-month continuous monitoring data of egrets, our results cover the findings using conventional manual observations, e.g., vertical stratification of egrets according to body size, and also open up opportunities of long-term bird surveys requiring intensive monitoring that is impractical using conventional methods, e.g., the weather influences on egrets, and the relationship of the migration schedules between the great egrets and little egrets.

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