Effects of Postfire Salvage Logging on Deadwood‐Associated Beetles

Abstract: In Canada and the United States pressure to recoup financial costs of wildfire by harvesting burned timber is increasing, despite insufficient understanding of the ecological consequences of postfire salvage logging. We compared the species richness and composition of deadwood‐associated beetle assemblages among undisturbed, recently burned, logged, and salvage‐logged, boreal, mixed‐wood stands. Species richness was lowest in salvage‐logged stands, largely due to a negative effect of harvesting on the occurrence of wood‐ and bark‐boring species. In comparison with undisturbed stands, the combination of wildfire and logging in salvage‐logged stands had a greater effect on species composition than either disturbance alone. Strong differences in species composition among stand treatments were linked to differences in quantity and quality (e.g., decay stage) of coarse woody debris. We found that the effects of wildfire and logging on deadwood‐associated beetles were synergistic, such that the effects of postfire salvage logging could not be predicted reliably on the basis of data on either disturbance alone. Thus, increases in salvage logging of burned forests may have serious negative consequences for deadwood‐associated beetles and their ecological functions in early postfire successional forests.     

Wastewater remediation using coal ash

 Small-scale domestic septic tanks discharge excess nutrients such as phosphorus and nitrogen, as well as pathogens, which can degrade local water supplies. Unfortunately, traditional chemical and physical treatments are not practicable for single-home dwellings. This work reports on a potentially attractive solution to protect local water supplies by using a low-cost industrial waste, coal ash, for contaminant removal. Coal ash is produced as a consequence of electric power generation. The majority of the ash is disposed of in landfills and surface impoundments, or stored on- or off-site, producing large hills or leveling valleys. Only a small portion of the ash is ever utilized, mainly by cement industries and road construction. For example, in Canada less than 25% is used. Therefore, if useful applications can be found, an opportunity exists to make better use of this waste material. Bench-scale laboratory experiments and full-scale field tests show that coal ash has the capacity to remove phosphorus from domestic waste water. The experimental and field data demonstrate that phosphate levels and calcium levels can be correlated, although not in a simple manner. In addition, the ash in packed beds removed total suspended solid (TSS), biological oxygen demand (BOD), ammonia nitrogen (NH₃—N), total Kjeldahl nitrogen (TKN), and E. coli. The removal of E. coli was close 100% in the cases studied. Received: May 20, 2002 / Accepted: October 5, 2002     

Spatial structure effects on the detection of patches boundaries using local operators

Landscapes exhibit various degrees of spatial heterogeneity according to the differential intensity and interactions among processes and disturbances that they are subjected to. The management of these spatially dynamical landscapes requires that we can accurately map them and monitor the evolution of their spatial arrangement through time. Such a mapping requires first the delineation of various spatial features present in the landscape such as patches and their boundaries. However, there are several environmental (spatial variability) as well as technical (spatial resolution) factors that impair our ability to accurately delineate patches and their boundaries as polygons. Here, we investigate how the spatial structure and spatial resolution of the data affect the accuracy of detecting patches and their boundaries over simulated landscapes and real data. Simulated landscapes consisted of two patches with parameterized spatial properties (patches’ level of spatial autocorrelation, mean value and variance) separated by a boundary of known location. Real data allowed the investigation of a more complex landscape where there is a known transition between two forest domains with unknown spatial properties. Boundary locations are defined using the lattice-wombling edge detector at various aggregation levels and the degree of patch homogeneity is determined using Getis-Ord’s G*. Results show that boundary detection using a local edge detector is greatly affected by the spatial conditions of the data, namely variance, abruptness of the spatial gradient between two patches and patches’ level of spatial autocorrelation. They also suggest that data aggregation is not a panacea for bringing out the ecological process creating the patches and that indicators derived from local measures of spatial association can be complementary tools for analysing spatial structures affecting boundary delineation.

Towards a Simple Indicator of Biodiversity

Policy makers in Canada have suggested that the scientific community should develop an indicator of biodiversity change that can be implemented quite quickly without a major new investment in monitoring systems. We propose that such an indicator can be developed from the theory of species gradients in community ecology. The term 'species gradients' refers to the increasing diversity of species through time under stable conditions, and the increasing diversity of species with the increased use of available resources. This theory is reviewed under four different headings: evolutionary ecology, the energy theory, the resource productivity theory and the thermodynamic mechanism. The theoretical arguments provide a basis to propose detection of the 'leaky ecosystem' as an indicator of biodiversity. We propose that it is possible to detect the leaky energetics of ecosystems by means of routinely available observations of outgoing longwave radiation.     

Atmospheric Change and Biodiversity in the Arctic

The Canadian Arctic is characterized by a high variation in landform types and there are complex interactions between land, water and the atmosphere which dramatically affect the distribution of biota. Biodiversity depends upon the intensity, predictability and scale of these interactions. Observations, as well as predictions of large-scale climate models which include ocean circulation, reveal an anomalous cooling of northeastern Canada in recent decades, in contrast to the overall significant increase in average annual temperature in the Northern Hemisphere. Predictions from models are necessary to forecast the change in the treeline in the 21st century which may lead to a major loss of tundra. The rate of change in vegetation in response to climate change is poorly understood. The treeline in central Canada, for example, is showing infilling with trees, and in some locations, northerly movement of the boundary. The presence of sea ice in Hudson Bay and other coastal areas is a major factor affecting interactions between the marine and terrestrial ecosystems. Loss of ice and therefore hunting of seals by polar bears will reduce bear and arctic fox populations within the region. In turn, this is likely to have significant effects on their herbivorous prey populations and forage plants. Further, the undersurface of sea ice is a major site for the growth of algae and marine invertebrates which in turn act as food for the marine food web. A rise in sea-level may flood coastal saltmarsh communities leading to changes in plant assemblages and a decline in foraging by geese and other consumers. The anomalous cooling in the eastern Arctic, primarily in late winter and early spring, has interrupted northern migration of breeding populations of geese and ducks and led to increased damage to vegetation in southern arctic saltmarshes as a result of foraging. It is likely that there has been a significant loss of invertebrates in those areas where the vegetation has been destroyed. Warming will have major effects on permafrost distribution and on ground-ice resulting in a major destabilization of slopes and slumping of soil, and disruption of tundra plant communities. Disruption of peat and moss surfaces lead to loss of insulation, an increase in active-layer depth and changes in drainage and plant assemblages. Increases of UV-B radiation will strongly affect vulnerable populations of both plants and animals. The indigenous peoples will face major changes in life style, edibility of food and health standards, if there is a significant warming trend. The great need is for information which is sensitive to the changes and will assist in developing an understanding of the complex interactions of the arctic biota, human populations and the physical environment.     

Accounting for intracultural variability in first nation environmental knowledge: A requisite for environmental monitoring and impact assessments

In many environmental monitoring and impact assessment processes, Indigenous communities are treated as intellectually homogenous and intracultural variation in environmental knowledge often goes unaccounted for. This not only poses obvious risks to the effectiveness of environmental impact assessments but also gives standing to those who question the credibility of traditional ecological knowledge and its contribution to environmental monitoring and assessment programs altogether. In this paper we describe the steps that were taken to account for intracultural variability in First Nation knowledge of fish and the potential impacts associated with the Peace River oil sands development in Alberta, Canada. Involving the delivery of a household survey to 1,127 First Nation households in 11 Peace River communities, our approach was successful in identifying regional, community, and household variability in fishing activity, and has allowed us to differentiate novice from expert knowledge holders. This research demonstrates the need to account for intracultural variability in First Nations environmental knowledge in order for traditional ecological knowledge to make meaningful contributions to environmental monitoring and assessment programs.     

How to facilitate (or discourage) community-based research: recommendations based on a Canadian survey

The impact of the extreme heat wave that affected Melbourne, Australia, in two distinct phases in January and February 2009 was severe, with 374 (heat) and 173 (bushfire) excess deaths. Whilst the human health issues have been covered in detail in policy and academic arenas, much less attention has been paid to the adverse impacts on urban infrastructure. Analysis of this event, underpinned by participatory actor-based research, has shown that the impacts were experienced disproportionately across different infrastructure types. For water, telecommunications and airports, the impacts were relatively minor and the impact on rail transport and roads (and to a lesser extent, seaports) was of moderate significance, whereas research findings indicate that the electricity sector was found to be the most vulnerable. This paper focuses on the sectors that were worst impacted: electricity, rail and road transport. Commentary identifies the direct and indirect impacts of the heat event, including associated cascading effects, as well as considering actual and potential adaptation responses both before and after the event. Concluding, the authors reflect on the implications of the heat wave for urban resilience, emphasising the crucial importance of understanding the urban environment as a complex and interconnected system.     

Perceived organizational support and perceived safety climate from the perspective of safety professionals: Testing reciprocal causality using a cross-lagged panel design

Introduction: The objective of this study was to determine the reciprocal relationship between safety professionals perceived organizational support (POS) and perceived safety climate. Safety professionals are most effective when they perceive support from management and employees and they also attribute most of their success to support from the organization. Their work directly improves safety climate, and organizations with a high safety climate show a higher value for the safety professional. The causal direction of this relationship is, however, unclear. Method: Using a sample of 162 safety professionals, we conducted a cross-lagged panel study over one year to examine whether safety professionals’ POS improves their perceived safety climate and/or whether safety climate also increases POS over time. Data were collected at two points and, after testing for measurement invariance, a cross-lagged SEM was conducted to analyze the reciprocal relationship. Results: Our findings show that safety professionals’ POS was positively related to perceived safety climate over time. Perceived safety climate, however, did not contribute to safety professionals’ POS. Conclusions: This study significantly adds to the discussion about the factors influencing safety professionals’ successful inclusion in organizations, enabling them to perform their work and, thus, improve occupational safety. Practical Applications: Since safety climate increases in organizations in which safety professionals feel supported, this study points out the kind of support that contributes to improved organizational safety. Support for safety professionals may come in classical forms such as approval, pay, job enrichment, and information on or influence over organizational policies.