Niagara region farmers' markets: local food systems and sustainability considerations

This article presents the findings of a survey of farmers' markets customers in the Niagara region of Ontario, Canada. The recent growth of farmers' markets in North America and the association of these markets with local food systems development provoke examination to gain insights into consumer motivations for patronizing these markets, and to then reflect on their potential role within locally oriented and sustainable food production systems. The survey carried out on customers of three Niagara region farmers' markets corroborates previous studies that noted that socioeconomic and cultural factors such as the importance of food freshness, support of local farmers and the local farm economy, and social interaction—embeddedness—are key expressions of people's support and interest in farmers' markets. This work serves to heighten our understanding of consumer attitudes toward direct marketing via farmers' markets, yields useful speculation about these markets and their roles in sustainable local food systems progress, and also raises critical questions about such customer patronage and associated farmers' markets potential in local food system development.     

Promoting pro-environmental behaviour: existing evidence and policy implications

This paper describes a recent study in the UK aimed at identifying how policy makers might more effectively encourage pro-environmental behaviours amongst their target audiences. The study included analysis and synthesis of theories and models of behaviour change, a range of current policy programmes and instruments and ‘real world’ practices of individuals, households, groups and organisations.The paper highlights some important considerations for future policy within the UK and, more widely, for other countries aiming to introduce comprehensive and multi-level policy programmes to encourage pro-environmental behaviours. To this end, it emphasises the complex and non-linear nature of environmental behaviours and, thus, the importance of adopting multi-levelled and multi-instrument integrated policies across whole systems of delivery.     

The Right Tree for the Job? Perceptions of Species Suitability for the Provision of Ecosystem Services

Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate tree species possessed those attributes. These data were combined to identify the species perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate species. Stakeholder perceptions substantially influence tree species selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services.     

Consequences of patch reef spacing for density-dependent mortality of coral-reef fishes

The spatial configuration of habitat patches can profoundly affect a number of ecological interactions, including those between predators and prey. I examined the effects of reef spacing on predator-prey interactions within coral-reef fish assemblages in the Bahamas. Using manipulative field experiments, I determined that reef spacing influences whether and how density-dependent predation occurs. Mortality rates of juveniles of two ecologically dissimilar species (beaugregory damselfish and yellowhead wrasse) were similarly affected by reef spacing; for both species, mortality was density dependent on reef patches that were spatially isolated (separated by 50 m), and density independent on reef patches that were aggregated (separated by 5 m). A subsequent experiment with the damselfish demonstrated that a common resident predator (coney) caused a substantial proportion of the observed mortality, independent of reef spacing. Compared to isolated reefs, aggregated reefs were much more likely to be visited by transient predators (mostly yellowtail snappers), regardless of prey density, and on these reefs, mortality rates approached 100% for both prey species. Transient predators exhibited neither an aggregative response nor a type 3 functional response, and consequently were not the source of density dependence observed on the isolated reefs. These patterns suggest that resident predators caused density-dependent mortality in their prey through type 3 functional responses on all reefs, but on aggregated reefs, this density dependence was overwhelmed by high, density-independent mortality caused by transient predators. Thus, the spatial configuration of reef habitat affected both the magnitude of total predation and the existence of density-dependent mortality. The combined effects of the increasing fragmentation of coral reef habitats at numerous scales and global declines in predatory fish may have important consequences for the regulation of resident fish populations.     

Opposite shifts in size at metamorphosis in response to larval and metamorph predators

Predation risk can cause organisms to alter the timing of life history switch points. Theory suggests that increased risk in an early life stage should select for switching earlier and smaller, while increased risk in the subsequent stage should select for switching later and larger. This framework has frequently been applied to metamorphosis in amphibians, with mixed results. Few studies examining the effect of larval predation risk on metamorphosis have observed the predicted pattern, and no studies, to our knowledge, have examined the effect of increased risk during and after metamorphosis on the timing of this switch point. Here we examine the effect of larval and post-metamorphic predation risk on metamorphosis in the red-eyed treefrog, Agalychnis callidryas. We raised tadpoles in the presence or absence of cues from caged water bugs fed larvae and cues from spiders fed emerging metamorphs. Water bugs are effective larval predators, while spiders are poor larval predators but prey on metamorphs. Furthermore, since spiders forage on the water surface it is possible that tadpoles could assess future risk from this predator. Predators induced opposite shifts in life history. Tadpoles emerged smaller and less developed in response to water bugs, but later and larger in response to spiders. Interestingly, predator effects on larval duration were not independent; tadpoles delayed emerging in response to spiders, but only in the absence of water bugs.     

Computer-based training for safety: comparing methods with older and younger workers

INTRODUCTION: Computer-based safety training is becoming more common and is being delivered to an increasingly aging workforce. Aging results in a number of changes that make it more difficult to learn from certain types of computer-based training. Instructional designs derived from cognitive learning theories may overcome some of these difficulties. METHODS: Three versions of computer-based respiratory safety training were shown to older and younger workers who then took a high and a low level learning test. RESULTS: Younger workers did better overall. Both older and younger workers did best with the version containing text with pictures and audio narration. DISCUSSION: Computer-based training with pictures and audio narration may be beneficial for workers over 45 years of age. IMPACT ON INDUSTRY: Computer-based safety training has advantages but workers of different ages may benefit differently. Computer-based safety programs should be designed and selected based on their ability to effectively train older as well as younger learners.     

Enhanced removal of mercury and lead by a novel and efficient surface-functionalized imogolite with nanoscale zero-valent iron material

Environmental Science and Pollution Research - A novel hybrid nanomaterial, nanoscale zero-valent iron (nZVI)-grafted imogolite nanotubes (Imo), was synthesized via a fast and straightforward...