Runoff and soil erosion in arable Britain: changes in perception and policy since 1945

The realisation that runoff and soil erosion was a problem came late to Britain and policies to tackle the problem have evolved slowly and may well have a taken a different route to that in other countries. The perception of soil erosion and runoff in Britain by three interest groups (researchers, policy makers and farmers) has changed over time since the 1940s. Prior to 1970 none of the groups considered erosion and runoff were problems. From then to 1985 researchers found that erosion was widespread. Between 1985 and 2005 researchers not only confirmed that erosion was a problem, but that runoff and its impacts (muddy floods and pollution of water courses by sediment, phosphate and pesticides) were also problems. These widespread and costly economic and environmental impacts led policy makers to tackle the problems of erosion and runoff. From 2005 farmers have had to keep their land in ‘Good Agricultural and Environmental Condition’ by, amongst other things, attempting to curtail erosion and runoff, to comply with regulation in order to receive subsidy. Policy change was also stimulated by changes in the European Union's Common Agricultural Policy and the passing by the EU of the ‘Water Framework Directive’. Policy, if it is to be evidence based, will always lag behind research. There is a continuing need for field-based monitoring to assess if regulation is working, to ensure compliance, and as a basis for future policy.     

A discussion of the potential impacts of climate change on the shorelines of the Northeastern USA

An increase in the rate of sea-level rise and potential changes in storminess represent important components of global climate change that will likely affect the extensive coasts of the Northeastern USA. Raising sea level not only increases the likelihood of coastal flooding, but changes the template for waves and tides to sculpt the coast, which can lead to land loss orders of magnitude greater than that from direct inundation alone. There is little question that sea-level rise, and in particular an increased rate of rise, will result in permanent losses of coastal land. However, quantitative predictions of these future coastal change remains difficult due in part to the complexity of coastal systems and the influence of infrequent storm events, and is further confounded by coastal science’s insufficient understanding of the behavior of coastal systems over decadal timescales. Recently, dramatic improvements in technology have greatly improved our capabilities to investigate and characterize processes and sedimentary deposits in the coastal zone, allowing us, for the first time, to address some of the over-arching problems involved in shoreline change. Despite advances in many areas of coastal geology, our fundamental understanding of shoreline change has been limited by a lack of a broad and integrated scientific focus, a lack of resources, and a lack of willingness on the part of policymakers who make crucial decisions about human activity along the coast to support basic research in this area. Although quantitative predictions remain constrained, there remains little doubt that the predicted climates changes will have profound effects upon the Northeastern coast.     

Development and initial validation of an Aviation Safety Climate Scale

PROBLEM: A need was identified for a consistent set of safety climate factors to provide a basis for aviation industry benchmarking. METHOD: Six broad safety climate themes were identified from the literature and consultations with industry safety experts. Items representing each of the themes were prepared and administered to 940 Australian commercial pilots. RESULTS: Data from half of the sample (N=468) were used in an exploratory factor analysis that produced a 3-factor model of Management commitment and communication, Safety training and equipment, and Maintenance. A confirmatory factor analysis on the remaining half of the sample showed the 3-factor model to be an adequate fit to the data. DISCUSSION: The results of this study have produced a scale of safety climate for aviation that is both reliable and valid. IMPACT ON INDUSTRY: This study developed a tool to assess the level of perceived safety climate, specifically of pilots, but may also, with minor modifications, be used to assess other groups' perceptions of safety climate.     

Carbon dioxide flux as affected by tillage and irrigation in soil converted from perennial forages to annual crops

Among greenhouse gases, carbon dioxide (CO(2)) is one of the most significant contributors to regional and global warming as well as climatic change. A field study was conducted to (i) determine the effect of soil characteristics resulting from changes in soil management practices on CO(2) flux from the soil surface to the atmosphere in transitional land from perennial forages to annual crops, and (ii) develop empirical relationships that predict CO(2) flux from soil temperature and soil water content. The CO(2) flux, soil temperature (T(s)), volumetric soil water content (theta(v)) were measured every 1-2 weeks in no-till (NT) and conventional till (CT) malt barley and undisturbed soil grass-alfalfa (UGA) systems in a Lihen sandy loam soil (sandy, mixed, frigid Entic Haplustoll) under irrigated and non-irrigated conditions in western North Dakota. Soil air-filled porosity (epsilon) was calculated from total soil porosity and theta(v) measurements. Significant differences in CO(2) fluxes between land management practices (irrigation and tillage) were observed on some measurement dates. Higher CO(2) fluxes were detected in CT plots than in NT and UGA treatments immediately after rainfall or irrigation. Soil CO(2) fluxes increased with increasing soil moisture (R(2)=0.15, P<0.01) while an exponential relationship was found between CO(2) emission and T(s) (R(2)=0.59). Using a stepwise regression analysis procedure, a significant multiple regression equation was developed between CO(2) flux and theta(v), T(s) (CO(2) [Formula: see text] ; R(2)=0.68, P0.01). Not surprisingly, soil temperature was a driving factor in the equation, which accounted for approximately 59% in variation of CO(2) flux. It was concluded that less intensive tillage, such as no-till or strip tillage, along with careful irrigation management will reduce soil CO(2) evolution from land being converted from perennial forages to annual crops.     

Towards a sustainable food production: modelling the impacts of climate change on maize and soybean production in Ghana

Environmental Science and Pollution Research - The Ghanaian economy relies heavily on maize and soybean production. The entire maize and soybean production system is low-tech, making it extremely...     

Conserving alpha and beta diversity in wood-production landscapes

International demand for wood and other forest products continues to grow rapidly, and uncertainties remain about how animal communities will respond to intensifying resource extraction associated with woody bioenergy production. We examined changes in alpha and beta diversity of bats, bees, birds, and reptiles across wood production landscapes in the southeastern United States, a biodiversity hotspot that is one of the principal sources of woody biomass globally. We sampled across a spatial gradient of paired forest land-uses (representing pre and postharvest) that allowed us to evaluate biological community changes resulting from several types of biomass harvest. Short-rotation practices and residue removal following clearcuts were associated with reduced alpha diversity (−14.1 and −13.9 species, respectively) and lower beta diversity (i.e., Jaccard dissimilarity) between land-use pairs (0.46 and 0.50, respectively), whereas midrotation thinning increased alpha (+3.5 species) and beta diversity (0.59). Over the course of a stand rotation in a single location, biomass harvesting generally led to less biodiversity. Cross-taxa responses to resource extraction were poorly predicted by alpha diversity: correlations in responses between taxonomic groups were highly variable (−0.2 to 0.4) with large uncertainties. In contrast, beta diversity patterns were highly consistent and predictable across taxa, where correlations in responses between taxonomic groups were all positive (0.05–0.4) with more narrow uncertainties. Beta diversity may, therefore, be a more reliable and information-rich indicator than alpha diversity in understanding animal community response to landscape change. Patterns in beta diversity were primarily driven by turnover instead of species loss or gain, indicating that wood extraction generates habitats that support different biological communities.