A bayesian network for comparing dissolved nitrogen exports from high rainfall cropping in southeastern Australia

Best management practices are often used to mitigate nutrient exports from agricultural systems. The effectiveness of these measures can vary depending on the natural attributes of the land in question (e.g., soil type, slope, and drainage class). In this paper we use a Bayesian Network to combine experiential data (expert opinion) and experimental data to compare farm-scale management for different high-rainfall cropping farms in the Hamilton region of southern Australia. In the absence of appropriate data for calibration, the network was tested against various scenarios in a predictive and in a diagnostic way. In general, the network suggests that transport factors related to total surface water (i.e., surface and near surface interflow) runoff, which are largely unrelated to Site Variables, have the biggest effect on N exports. Source factors, especially those related to fertilizer applications at planting, also appear to be important. However, the effects of fertilizer depend on when runoff occurs, and, of the major factors under management control, only the Fertilizer Rate at Sowing had a notable effect. When used in a predictive capacity, the network suggests that, compared with other scenarios, high N loads are likely when fertilizer applications at sowing and runoff coincide. In this paper we have used a Bayesian Network to describe many of the dependencies between some of the major factors affecting N exports from high rainfall cropping. This relatively simple approach has been shown to be a useful tool for comparing management practices in data-poor environments.     

Protecting asset value and driving performance with a dynamic,risk-based contingency fund

We present a risk-based contingency fund management methodology to mitigate the impact of external risks on asset value and performance. Many asset intensive industries, such as water and energy utilities, are significantly affected by external risks such as extreme weather events. We put the case for a centrally held risk-based contingency fund that would mitigate against ‘medium’ impact ‘medium’ probability events that fall outside of large losses covered by insurance and smaller ‘normal’ operating losses. Our risk-based contingency approach is appropriate for short-term business planning (1–5 years) and would complement longer term planning, for example climate change adaptation and mitigation strategies. Our approach offers a risk-based methodology to manage contingency that is explicit and defensible. Critically, our methodology allows contingency to be managed dynamically as risk probabilities and impacts change, creating a mechanism for contingency funds to be periodically released if risk exposure reduces. The long-term benefit of dynamic, risk-based contingency is to reduce the impact of external risks and support long-term sustainability.     

Evaluating the process of triple bottom line reporting: Increasing the potential for change1

Abstract

This paper presents an evaluation framework that aims to improve the outcomes of triple bottom line (TBL) reporting. Currently, most assessments of TBL reporting focus on report content. Our view is that effective evaluation of TBL reporting should go beyond reports as the outputs of a process and focus on what is being learned through the process, the capacity- and relationship-building that might eventuate, and how this impacts on the development of sustainability. To enable more effective reflection of TBL reporting processes, we developed a set of evaluation criteria focused on the process of reporting. These criteria were identified from case studies of social, environmental and/or sustainability reporting processes documented in the literature. A large number of potential criteria were synthesised into three desired outcomes of TBL reporting and 10 prompts for discussion and reflection during evaluation. This evaluation framework should assist those dedicated to challenging assumptions that inhibit progress towards a sustainable future for society.     

Reproductive sharing and proximate factors mediating cooperative breeding in the African wild dog (Lycaon pictus)

Although dominant African wild dogs (Lycaon pictus) are generally believed to be the sole breeders within a pack, earlier behavioral and endocrine data suggest that reproduction could be shared with subordinates. We performed an extensive behavioral, demographic, and genetic evaluation of a wild dog population in South Africa to examine the level of such sharing and the proximate mechanisms influencing reproductive contributions of each sex. While a majority of pups were born to dominants because of a lack of subordinate potential breeders, we discovered a substantial portion of reproductive sharing between dominants and subordinates. Compared with alpha females that mated annually, subordinate beta females bred in 54.5% of years whereas thetas never bred. The three top-ranking males all sired pups (56.0%, 32.0%, and 12.0%, respectively) when three or more adult males were present. With only two pack males, alpha and beta individuals shared reproduction nearly equally (55.2% and 44.8%, respectively), and litters of mixed paternity were discovered on eight of 15 (53.3%) occasions. A skewed adult sex-ratio and frequent alpha mortalities for females and behavioral aggression in males allowed most individuals to attain dominant status in their lifetime, creating a constantly shifting social hierarchy. Genetic parentage results corresponded to reported hormone profiles, suggesting physiological suppression in some lower-ranked individuals of both sexes. Thus, a combination of demographic, behavioral, and hormonal proximate factors mediates reproductive partitioning in wild dogs. We conclude that reproductive sharing can be significant in this species, especially for males that have less robust suppressive mechanisms than females.     

A moving target: planning Britain's inner cities

The authors look at Britain's post‐war response to the challenge of the Inner Cities and attempts to account for this response's more obvious failings. The paper considers the challenge facing the planners and considers the nature of their response, concluding that the future of planning as a weapon in the armoury of public policy is assured.