A Decision-Support System for Prioritizing Restoration Sites on the Mississippi River Alluvial Plain

Conversion of forested wetlands to agricultural use and the resulting fragmentation of the landscape has led to concerns for the functional integrity of the Mississippi River Alluvial Plain ecosystem. We describe an effort spearheaded by The Nature Conservancy to initiate a multi-decade partnership dedicated to creating and implementing a viable, cooperative, landscape-level restoration project in the Mississippi River Alluvial Plain. Important phases of the process during the first 5 years were (1) initiation of the development of an extensive network of partners, including state and federal agencies, private land owners, conservation groups, academicians, and other interested citizens; (2) development of a geographic information system (GIS) for the entire extent of the ecosystem; and (3) for one watershed, the Tensas basin in northeastern Louisiana, refinement of a high resolution GIS to generate more detailed land-use conversion statistics to demonstrate the feasibility of a semi-objective, landscape-scale restoration planning procedure, including methodology for prioritization of existing wetland forest patches and areas most suitable for reforestation and connection via corridors.     

Effects of workplace thermal conditions on safe work behavior

The effect of workplace thermal conditions on worker safety has not previously been adequately investigated, due in part to the difficulty of defining a suitable safety performance measure. This report describes a study conducted in two industrial plants to determine if a correlation exists between the safety-related behavior of workers and workplace thermal conditions. Both heat exposure measurements and behavioral observations were taken over a 14-month period, for a total of over 17,000 observations. The results indicate that temperatures below and above those typically preferred by most people have a significantly detrimental effect on the safety-related behavior of workers. This is demonstrated by an index based on the ratio of observed unsafe behaviors to the total number of observed behaviors. The relationship between this index of unsafe behavior and the ambient temperature formed a U-shaped curve. The minimum unsafe behavior index occurred within the zone of preferred temperature (approximately 17°C to 23°C, WBGT). Other factors such as metabolic workload and time during the shift also had significant effects on worker safety-related behavior.     

Adaptive sampling and analysis programs for contaminated soils

Adaptive sampling and analysis programs (ASAPs) provide a cost-effective alternative to traditional sampling program designs. ASAPs are based on field analytical methods for rapid sample turnaround and field-based decision support for guiding the progress of the sampling program. One common objective of ASAPs is to delineate contamination present in soils, either to support feasibility studies or remedial action designs. An ASAP based on portable gas chromatograph/ mass spectrograph (GC/MS) technologies developed at Tufts University combined with decision support tools created at Argonne National Laboratory was used to delineate explosives contamination in soils at Joliet Army Ammunition Plant, Joliet, Illinois. Tufts' GC/MS technologies provided contaminant-specific identification and quantification with rapid sample turnaround and high sample throughput. Argonne's decision support tools estimated contamination extent, determined the uncertainty associated with those estimates, and indicated where sampling should continue to minimize uncertainty. In the case of Joliet, per sample analytical costs were reduced by 75 percent as compared to the cost of off-site laboratory analyses for explosives. The use of an ASAP resulted in a much more accurate identification and delineation of contaminated areas than a traditional sampling program would have with the same number of samples collected on a regular grid. While targeting explosives contamination in soils at Joliet, the ASAP technologies used in this demonstration have much broader application.     

Evaluating Quality of Life, Economic Vulnerabilities, and Drivers of Ecosystem Change

We examined regional conditions and trends related to quality of life and potential vulnerabilities of these factors to changes in the condition of natural resources in the Mid-Atlantic Region, USA. We selected a variety of variables on economic and socio-demographic conditions that demonstrate links between the condition of natural areas and human concerns and that quantify dependencies on resources. We extracted data from economic and population census databases for counties within the study area and present a subset of results of the cluster analyses used to describe condition and potential risks due to distinct combinations of variables. We found that the same variables used to judge quality of life were often correlated with increasing population and thus were likely to be related to land pressures and risks to natural resources. Within the region, economic dependence on resource-harvesting industries such as forestry and fisheries was low (less than 4% of total earnings at most), however, the potential for natural amenities to attract residents appeared to be growing as the self-employed and otherwise mobile people settled in areas with affordable housing and natural amenities. Suburban residential spread had been occurring in both the close-in and distant suburbs of the region's urban areas and some rural, growth appeared to be driven, in part, by businesses migrating to suburbs. Further work is needed to tease apart causal factors for the trends we observed, but correlations clearly existed in some areas between increasing populations and quality of natural surroundings.     

Development and Application of Computer Simulation Tools for Ecological Risk Assessment

Based on a review of available models for ecological risk estimation, most are site-specific and their applications are limited. However, general models, which can be easily adapted to other sites, remain few, in addition, they are simple and associated with significant uncertainties. In this paper, an approach is introduced for an ecological risk assessment (ERA) model that can be modified for site-specific conditions. Using computer simulation as a screening tool for ecological risk assessment can assist environmental managers and policy decision-makers in the planning and implementation of potentially highly focused assessments and remediation, should the ERA dictate the need. The model was integrated with a Windows-based interface and interactive database management system (DBMS) as a user-friendly software package. In addition, based on trophic sources, a food web has been integrated into the framework of the DBMS. In an effort to evaluate the model, a case study was implemented to characterize the effects on an ecosystem of replacing electroplated chromium coatings with sputtered tantalum at U.S. Army Yuma and Aberdeen Proving Grounds. Potential exposure pathways included ingestion, inhalation, and dermal absorption for terrestrial animals; root and foliar uptake for plants; and direct absorption for aquatic species. Overall, results showed that the most significant exposure resulted from molybdenum and hexavalent chromium, which posed higher risks to select aquatic and terrestrial species at both sites. On the other hand, tantalum (with vanadium as the surrogate) resulted in the least risk to all receptors within the studied areas. A sensitivity analysis demonstrated that soil-water distribution coefficients have a significant impact on the results. Based on the results, neither molybdenum nor chromium are recommended as a coating in gun barrels, and further study would be essential to address any affected firing range area. Tantalum is recommended for use, although for those species receiving a slight adverse risk, field investigations that include receptor sampling maybe necessary once soil/sediment and water sampling validates projected concentrations.     

Rapid Assessment of Plant Diversity Patterns: A Methodology for Landscapes

We present a rapid, cost-efficient methodology to link plantdiversity surveys from plots to landscapes using: (1) unbiasedsite selection based on remotely sensed information; (2) multi-scale field techniques to assess plant diversity; (3)mathematical models (species-area curves) to estimate thenumber of species in larger areas corrected for within-typeheterogeneity; and (4) mathematical techniques to estimatetotal species richness and patterns of plant diversity in alandscape. We demonstrate the methodology in a 754 ha studyarea in Rocky Mountain National Park, Colorado, U.S.A.,using four 0.025 ha and twenty-one 0.1 ha multi-scalevegetation plots. We recorded 330 plant species (1/3 thenumber of plants recorded in the 1074 km² Park) in the2.2 ha area within the plots: this represents a samplingintensity of 0.29% of the 754 ha study site. We estimated 552plant species, about half the plant species recorded in the Park,in just 0.7% of the Parks area. We show how this rapid,cost-efficient methodology: (1) produces a rich informationbase on the patterns of native plant diversity and thedistribution of non-native plant species and keystoneecosystems; and (2) can be easily adapted for other nationaland state parks, national forests, wildlife refuges, and nature reserves.     

Growth patterns of Amphiura filiformis support the hypothesis of organic enrichment in the Skagerrak-Kattegat area

Population size structure, abundance and biomass of the burrowing ophiuroid Amphiura filiformis were measured in the period 1970 to 1989 at three widely spaced sites at 55 to 100 m depth in the Skagerrak-Kattegat area. This species is a dominant component of the fauna in the area, and also one of the species accounting for a great part of a recent general increase in benthic biomass. Abundance at two of the sites and biomass at all three sites increased significantly with time from the 1970s onwards. Maximum individual size and growth of the cohort of adults showed a marked increase in the period 1980 to 1983 at the three sites. In the 1980s annual absolute growth increments of the recruits were clearly greater than in the 1970s, and size-specific growth rates were virtually unchanged. These results are consistent with the hypothesis that recent increases in benthic biomass in this area result from increased input of food to the benthos. A. filiformis has the potential for rapid growth; estimated maximum weight-specific growth rates were more than 1.5% d^-1 in the disc diameter interval 3 to 9 mm, which is comparable to rates found in shallow water filtering bivalves. The maximum disc diameter growth rate was ca. 0.4 mm mo^-1.     

Job stress,incivility, and counterproductive work behavior (CWB): the moderating role of negative affectivity

The current study was designed to replicate findings from previous research regarding the relationships between job stressors, negative affectivity, and counterproductive work behavior (CWB) using peer‐reported data and to assess the effects of workplace incivility on employee satisfaction and CWB. Results indicate that incivility, organizational constraints, and interpersonal conflict were negatively related to job satisfaction and positively related to CWB. Support was also found for the role of negative affectivity as a moderator of the relationship between job stressors and CWB, although only one significant moderator was found using peer‐reported CWB. In general, the relationships between job stressors and CWB were stronger for individuals high in negative affectivity than for individuals low in negative affectivity. Copyright © 2005 John Wiley & Sons, Ltd.     

MODELED REGIONAL CLIMATE CHANGE IN THE HYDROLOGIC REGIONS OF CALIFORNIA: A CO2 SENSITIVITY STUDY1

ABSTRACT: Using a regional climate model (RegCM2.5), the potential impacts on the climate of California of increasing atmospheric CO₂ concentrations were explored from the perspective of the state's 10 hydrologic regions. Relative to preindustrial CO₂ conditions (280 ppm), doubled preindustrial CO₂ conditions (560 ppm) produced increased temperatures of up to 4°C on an annual average basis and of up to 5°C on a monthly basis. Temperature increases were greatest in the central and northern regions. On a monthly basis, the temperature response was greatest in February, March, and May for nearly all regions. Snow accumulation was significantly decreased in all months and regions, with the greatest reduction occurring in the Sacramento River region. Precipitation results indicate drier winters for all regions, with a large reduction in precipitation from December to April and a smaller decrease from May to November. The result is a wet season that is slightly reduced in length. Findings suggest that the total amount of water in the state will decrease, water needs will increase, and the timing of water availability will be greatly perturbed.