Application of multiple-population viability analysis to evaluate species recovery alternatives

Population viability analysis (PVA) is a powerful conservation tool, but it remains impractical for many species, particularly species with multiple, broadly distributed populations for which collecting suitable data can be challenging. A recently developed method of multiple-population viability analysis (MPVA), however, addresses many limitations of traditional PVA. We built on previous development of MPVA for Lahontan cutthroat trout (LCT) (Oncorhynchus clarkii henshawi), a species listed under the U.S. Endangered Species Act, that is distributed broadly across habitat fragments in the Great Basin (U.S.A.). We simulated potential management scenarios and assessed their effects on population sizes and extinction risks in 211 streams, where LCT exist or may be reintroduced. Conservation populations (those managed for recovery) tended to have lower extinction risks than nonconservation populations (mean = 19.8% vs. 52.7%), but not always. Active management or reprioritization may be warranted in some cases. Eliminating non-native trout had a strong positive effect on overall carrying capacities for LCT populations but often did not translate into lower extinction risks unless simulations also reduced associated stochasticity (to the mean for populations without non-native trout). Sixty fish or 5–10 fish/km was the minimum reintroduction number and density, respectively, that provided near-maximum reintroduction success. This modeling framework provided crucial insights and empirical justification for conservation planning and specific adaptive management actions for this threatened species. More broadly, MPVA is applicable to a wide range of species exhibiting geographic rarity and limited availability of abundance data and greatly extends the potential use of empirical PVA for conservation assessment and planning.     

Transformational leadership,psychological empowerment,and the moderating role of mechanistic–organic contexts

The current study examines the empowering effects of transformational leaders and the extent to which these effects differ across mechanistic–organic organizational contexts. Psychological empowerment is hypothesized to provide a comprehensive motivational mechanism explaining the relationships between transformational leadership and employee job‐related behaviors. In addition, the relationships between transformational leadership, employee psychological empowerment, and job‐related behaviors are hypothesized to be stronger in organizations with more organic as opposed to mechanistic structures. Results based on a cross‐organizational sample of employees and their immediate supervisors provide support for the hypothesized relationships. Psychological empowerment mediated relationships between transformational leadership and employee task performance and organizational citizenship behaviors. The mediating role of psychological empowerment was then found to be conditional upon mechanistic–organic contexts. More specifically, organic structures enhanced, whereas mechanistic structures constrained, the empowering influence of transformational leaders. In highly mechanistic contexts, the indirect effects were no longer statistically significant. Implications for theory, research, and organizational management are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

Accumulation of radiocesium by mushrooms in the environment: a literature review

During the last 50 years, a large amount of information on radionuclide accumulators or "sentinel-type" organisms in the environment has been published. Much of this work focused on the risks of food-chain transfer of radionuclides to higher organisms such as reindeer and man. Until the 1980s and 1990s, there were few published data on the radiocesium ((134)Cs and (137)Cs) accumulation by mushrooms. The present review of published data for (134,137)Cs accumulation by mushrooms in nature discusses the aspects that promote (134,137)Cs uptake by mushrooms and focuses on mushrooms that demonstrate a propensity for use in the environmental biomonitoring of radiocesium contamination. Transfer factors (TF, as dry weight concentration in fruiting body divided by concentration in substrate) ranged up to 24 (unitless), and aggregate transfer factors (T(ag), as Bq(137)Cs/kg dw in fruiting body divided by the aerial deposition as Bq/m(2)) ranged up to 8m(2)/kg dw.     

Temperature and salinity: two climate change stressors affecting early development of the New Zealand sea urchin Evechinus chloroticus

Temperature and salinity are important environmental factors affecting the normal functioning of marine animals, particularly animals such as sea urchins living in shallow waters and tide pools. Here, we evaluated the effect of different combinations of temperature and salinity on early embryos of the endemic New Zealand sea urchin Evechinus chloroticus. Animals were collected at Matheson’s Bay (36º18′17′′S; 174º47′51′′E) in north-eastern New Zealand in February 2013. Embryos were exposed to five salinities (29, 31, 34, 35 and 37 ppt) and two temperatures (18 and 21 °C) during the first 24 h of development. Low salinity (29 ppt) affected all parameters (fertilization, development rate, gastrulation and normal development), with ca. 50 % of embryos surviving at 29 ppt, whereas seawater temperature only affected development rate and gastrulation. An increase in temperature from 18 to 21 °C minimized the negative effect of low salinity (≤31 ppt) on development rate and gastrulation of E. chloroticus. Overall, the results of this study suggest that early embryos of E. chloroticus have developmental plasticity to withstand reductions in salinity up to 29 ppt; however, it is still unknown whether the surviving embryos will be able to complete larval development at low salinities, particularly whether the embryos and larvae are carried into extreme environments such as estuaries where salinity is even lower. Multistressor studies are very important for climate change research as multiple environmental factors will act together in the wild, having major consequences for development and recruitment of marine invertebrates.     

Evaluation of alternative approaches for screening contaminated sediments and soils for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans

Traditional high resolution mass spectrometry (HRMS) analysis for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) can be time consuming and expensive. Consequently, alternative methods are of great interest to regulatory agencies and others characterizing contaminated sites. One factor that hinders acceptance of alternative methods is a lack of performance information that assesses the alternative method's impacts on analytical results. The U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation Monitoring and Measurement Technologies Program (EPA SITE MMT) encourages the development and implementation of innovative and alternative monitoring methods by providing performance information on site characterization technologies. This paper presents a comparison of the results obtained from laboratory-based alternative approaches for screening sediment and soil samples for dioxin toxicity equivalents (TEQ(D/F)) to results obtained using traditional HRMS. The laboratory-based approaches included modifying the traditional HRMS analysis to make it more cost-effective (alternate 1613B), analyzing extracts that had been prepared for HRMS using low resolution mass spectrometry, and determining total organic carbon (TOC) content as an indicator of PCDD/F content. These comparisons demonstrated that TEQ(D/F) values generated using toxicity equivalency factors proposed by the World Health Organization in 1998 applied to alternate 1613B and LRMS analyses have a strong linear correlation to the TEQ(D/F) values derived in the same fashion from traditional HRMS analysis. These results would have placed >90% of the samples within the same concentration intervals using ranges of <0.05, 0.05-0.50, 0.50-5, and >5ng TEQ/g. Natural log transformed data for TOC had significantly weaker correlation to TEQ(D/F), indicating that TOC is not a reliable indicator of TEQ(D/F) concentrations.     

Improving Peer Review of Listings and Recovery Plans under the Endangered Species Act

Abstract: We discuss several challenges encountered in peer review of Endangered Species Act listings and recovery plans, with particular attention to Meffe et al.'s (1998) statement on independent scientific review in natural resource management. First, Endangered Species Act listing documents and recovery plans pose a diverse array of scientific questions, and we suggest that overall effectiveness of peer review may be increased by segregating the critical issues and identifying specific reviewers for each issue. Some scientific reviewers may be unfamiliar with the decision standards prescribed by the Endangered Species Act and implementing policies. Unnecessary confusion could be prevented by providing reviewers with information about these standards and by requesting that reviewers clearly differentiate their assessment of decisions that must be based on available information from recommendations for future research. Short review periods constitute another constraint on careful review, but tight deadlines are fairly intractable in the context of the Endangered Species Act. We suggest that short time frames could be partially ameliorated by narrowing the scope of issues to be treated by each reviewer, and we discuss the issue of providing monetary compensation for efficient review. Finally, Endangered Species Act listing decisions and recovery planning may profit from more frequent peer review of intermediate analyses that precede publication of formal proposals or complete plans.     

Modelling the connection between energy consumption and carbon emissions in North Africa: Evidence from panel models robust to cross-sectional dependence and slope heterogeneity

Environment, Development and Sustainability - This paper explored the link between energy consumption and carbon emissions in North Africa through an Environmental Kuznets Curve (EKC) framework....     

Estimating the effects of urban residential development on water quality using microdata

In this study, we examine the impact on water quality of urbanization using disaggregate data from Wake County, North Carolina. We use a unique panel data set tracing the conversion of individual residentially zoned land parcels to relate the density of residential development and the change in residential land use to three measures of water quality. Using a spatial econometrics model, we relate spatially and temporally referenced monitoring station readings to our measures of residential land use while controlling for other factors affecting water quality. We find that both the density of residential land use and the rate of land conversion have a negative impact on water quality. The impacts of these non-point sources are found to be larger in magnitude than those from urban point sources.