Germination responses of a dry sclerophyll forest soil-stored seedbank to fire related cues

Fire is an integral component of many ecosystems worldwide. Many plant species require fire-related cues, primarily heat and smoke, to trigger germination. Despite the importance of this process, the responses of many Australian species to these cues are unknown. Without this knowledge fire management strategies may be developed that are inappropriate for individual species and vegetation communities. In this study we examined the responses of a dry sclerophyll forest seed bank to heat and smoke germination cues. Analysis was possible for 48 taxa within the soil seedbank with 34 of these showing a response to one or both of the germination cues. 10 species responded to the heat treatment, 11 species responded to the smoke treatment and 13 species responded to both the heat and smoke treatments. Germination cues acted independently for all species considered. Results in this study were consistent with published reports for most species, although some differences were seen at the species and genus level. The study highlights the importance of fire-related cues in enhancing germination of a large proportion of the species occurring in dry sclerophyll forests

On the Balance Sheet-Based Model of Financial Reporting

The FASB adopted a balance sheet-based model of financial reporting about 30 years ago, and this model has been gradually expanded and solidified to become the required norm around the world today. Currently, the FASB and the IASB are re-considering their Conceptual Framework, and this is the right time to have a much-needed debate about the proper conceptual foundations of accounting. This paper argues that the balance sheet orientation of accounting standard-setting is flawed, for the following reasons: 1. Accounting is supposed to reflect business reality, and thus the essential features of the financial reporting model need to reflect the essential features of the underlying business model. However, the balance sheet orientation of financial reporting is at odds with the economic process of advancing expenses to earn revenues, which governs how most businesses create value, and which represents how managers and investors view most firms. 2. The adoption of the balance sheet approach was driven by conceptual considerations; standard setters argued that the concept of assets is more fundamental and logically prior to the concept of income. However, this paper argues that the concept of income is clearer and practically more useful than the concept of assets, especially with the recent proliferation of intangible assets. 3. Earnings is the single most important output of the accounting system. Thus, intuitively, improved financial reporting should lead to improved usefulness of earnings. However, the continual expansion of the balance sheet approach is gradually destroying the forward-looking usefulness of earnings, mainly through the effect of various asset re-valuations, which manifest as noise in the process of generating normal operating earnings. During the last 40 years, the volatility of reported earnings has doubled and the persistence of earnings has gone down by about a third, while there is little change in the properties of the underlying business fundamentals. 4. The balance sheet approach has pushed accounting into incorporating more and more valuation estimates into financial reports, creating tautological and dangerous feedback loops between financial markets and the real economy. The paper concludes with two suggestions about a "good" model of financial reporting. The first suggestion is that accounting needs to make a sharp theoretical and practical distinction between operating and financing-type activities and assets, and this distinction needs to be reflected in all financial statements. The second suggestion is that for most firms the accounting for operating activities needs a renewed emphasis on the principle of matching of expenses to revenues

Into the firing line: civilian ingress during the 2013 Red October bushfires, Australia

A major issue for bushfire management arises when residents decide to leave a safe area and enter the fire zone to rescue or defend their property, pets, loved ones or other assets. Here, we use statistical and narrative analyses of data from an online survey and semi-structured interviews with residents affected by the 2013 Red October bushfires in New South Wales, Australia. The survey results revealed that of the 58 % of respondents who were not at home at the time the threat became apparent, 65 % indicated that they attempted to get home prior to the arrival of the fire front. In doing so, many endangered themselves, their family, friends and emergency services personnel. This paper discusses the shortcomings of bushfire survival plans and official risk communication, which do not cater well for household units that are divided or unattended when a bushfire starts. Findings suggest that to enhance bushfire safety and preparedness, emergency managers should acknowledge and speak more directly to the specific constraints to action for particular social groups at the wildland-urban interface, including families with school-age children, commuters and absentee landholders

Rapid mortality transition of Pacific Islands in the 19th century

The depopulation of Pacific islands during the 16th to 19th centuries is a striking example of historical mass mortality due to infectious disease. Pacific Island populations have not been subject to such cataclysmic infectious disease mortality since. Here we explore the processes which could have given rise to this shift in infectious disease mortality patterns. We show, using mathematical models, that the population dynamics exhibited by Pacific Island populations are unlikely to be the result of Darwinian evolution. We propose that extreme mortality during first-contact epidemics is a function of epidemiological isolation, not a lack of previous selection. If, as pathogens become established in populations, extreme mortality is rapidly suppressed by herd immunity, Pacific Island population mortality patterns can be explained with no need to invoke genetic change. We discuss the mechanisms by which this could occur, including (i) a link between the proportion of the population transmitting infectious agents and case-fatality rates, and (ii) the course of infection with pathogens such as measles and smallpox being more severe in adults than in children. Overall, we consider the present-day risk of mass mortality from newly emerging infectious diseases is unlikely to be greater on Pacific islands than in other geographical areas

Some wildfire ignition causes pose more risk of destroying houses than others

Many houses are at risk of being destroyed by wildfires. While previous studies have improved our understanding of how, when and why houses are destroyed by wildfires, little attention has been given to how these fires started. We compiled a dataset of wildfires that destroyed houses in New South Wales and Victoria and, by comparing against wildfires where no houses were destroyed, investigated the relationship between the distribution of ignition causes for wildfires that did and did not destroy houses. Powerlines, lightning and deliberate ignitions are the main causes of wildfires that destroyed houses. Powerlines were 6 times more common in the wildfires that destroyed houses data than in the wildfires where no houses were destroyed data and lightning was 2 times more common. For deliberate-and powerline-caused wildfires, temperature, wind speed, and forest fire danger index were all significantly higher and relative humidity significantly lower (P \u3c 0.05) on the day of ignition for wildfires that destroyed houses compared with wildfires where no houses were destroyed. For all powerline-caused wildfires the first house destroyed always occurred on the day of ignition. In contrast, the first house destroyed was after the day of ignition for 78% of lightning-caused wildfires. Lightning-caused wildfires that destroyed houses were significantly larger (P \u3c 0.001) in area than human-caused wildfires that destroyed houses. Our results suggest that targeting fire prevention strategies around ignition causes, such as improving powerline safety and targeted arson reduction programmes, and reducing fire spread may decrease the number of wildfires that destroy houses

GIS applications to maritime boundary definitions: diplomacy on and under the sea

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