Importance of Roadless Areas in Biodiversity Conservation in Forested Ecosystems: Case Study of the Klamath-Siskiyou Ecoregion of the United States

Abstract: Although many roadless areas on federal lands have been mapped in the United States since the 1970s, there has been little specific research on how and to what degree roadless areas contribute to biodiversity conservation. We examined the ecological attributes of mapped roadless areas for the Klamath-Siskiyou ecoregion of northwestern California and southwestern Oregon (U.S.A.). Attributes examined include special elements (such as natural heritage, serpentine geology, late-seral forests, Port Orford cedar [ Chamaecyparis lawsoniana ] ), and key watersheds; elevation and habitat representation; and overall landscape connectivity. We compared designated wilderness to roadless areas, giving special attention to the relative importance of small roadless areas (405–2024 ha). We mapped nearly 500 roadless areas of ≥405 ha. Roadless areas occupied more than twice the land area of wilderness (approximately 27% of the entire ecoregion) and contained approximately 36% of the known occurrences of heritage elements, 37% of the mapped serpentine habitats, 36% of the remaining late-seral forests, 60% of Port Orford cedar strongholds, and 42% of key watersheds for aquatic biodiversity. In addition, roadless areas were composed of significant amounts of low- and mid-elevation sites and a substantial number of the 214 mapped physical-biological habitat types with strong complementarity with designated wilderness. Fragmentation analyses showed that roadless areas contributed to regional connectivity in important ways. Also, small roadless areas were an important component of the roadless-areas conservation assessment. For the Klamath-Siskiyou ecoregion, roadless areas and designated wilderness provide an important foundation upon which to develop a comprehensive regional conservation strategy.     

Stabilization of Heavy Metal Containing Hazardous Wastes with Byproducts from Advanced Clean Coal Technology Systems

ABSTRACT

The purpose of this investigation was to evaluate the success of residues from advanced Clean Coal Technology (CCT) systems as stabilization agents for heavy metal containing hazardous wastes. In the context examined here, stabilization refers to techniques that reduce the toxicity of a waste by converting the hazardous constituents to a less soluble, mobile, or toxic form.¹ Three advanced CCT byproducts were used: coal waste-fired circulating fluidized bed combustor residue, pressurized fluidized bed combustor residue, and spray drier residue. Seven metal-laden hazardous wastes were treated: three contaminated soils, two air pollution control dusts, wastewater treatment plant sludge, and sandblast waste. Each of the seven hazardous wastes was treated with each of the three CCT byproducts at dosages of 10, 30, and 50% by weight (byproduct:waste). The treatment effectiveness of each mixture was evaluated by the Toxicity Characteristic Leaching Procedure. Of the 63 mixtures evaluated, 21 produced non-hazardous residues. Treatment effectiveness can likely be attributed to mechanisms such as precipitation and encapsulation due to the formation of hydrated calcium silicates and calcium sulfo-alu-minates. Results indicate that these residues have potential beneficial uses to the hazardous waste treatment community, possibly substituting for costly treatment chemicals.     

Characterization of Ozone During Consecutive Drought and Wet Years at a Rural West Virginia Site

Ozone concentrations at a rural-remote site in a forested region of north-central West Virginia were monitored during 1988 and 1989, a drought and wet year, respectively. During 1988, the absolute maximum average concentration for a single hour was 156 ppb, while it was only 107 ppb in 1989. Overall, the frequency of high concentrations was greater during 1988; the 120 ppb National Ambient Air Quality Standard was exceeded 17 times. The 7-h period encompassing the highest growing season concentrations for this site over the 2-yr period is 1100- 1759 h EST, rather than the period 0900-1559 h originally used by the National Crop Loss Assessment Network. The 7-h growing season means (0900-1559 h) of 52.6 ppb and 47.1 ppb for 1988 and 1989, respectively, compare well to those reported for the Piedmont/Mountain/Ridge-Valley area, but are higher than those for other surrounding areas. The diurnal ozone patterns, as well as the distribution of concentration ranges and timing of seasonal maxima, suggest that long-range transport of ozone and its precursors probably is an important factor at this site, given its remote and rural character.     

Avoidance and toxicity responses of fish to intermittent chlorination

The ability of fish to actively avoid concentrations of chlorine in a steep, horizontal, laboratory-controlled gradient was found to be species-specific and dependent upon the acclimation temperature, water quality conditions, and the type of chlorine residual tested. Comparison of behavioral avoidances with the results from bioassays using some form of intermittent chlorination, as reported in the literature, indicated that LC₅₀ concentrations (levels that cause the mortality of half the test individuals in a designated time period) usually exceeded avoidance threshold concentrations.This chlorine avoidance study, which was carried out in a field laboratory that utilized New River water for holding and testing procedures, was located at the Glen Lyn power plant in southwestern Virginia. Two basic types of avoidance trials were employed, TRC (total residual chlorine) and chloramine (CRC) exposures. The TRC trials contained variable amounts of free (FRC) and combined residual chlorine (CRC) depending upon water quality, while in chloramine trials, the TRC exposure was mainly comprised of monochloramine with little or no FRC. The first significant avoidance in TRC trials for several fish species tested, varied from 0.05 mg/1 for coho salmon (Oncorhynchus kisutch) to 0.40 for channel catfish (Ictalurus punctatus). Low levels of hypochlorous acid (HOCl), which are considered to be a potentially toxic constituent of FRC, appeared to consistently influence the avoidance response. Initial avoidance concentrations to HOCl ranged from 0.01–0.02 mg/1 for coho salmon to 0.04–0.12 mg/1 for channel catfish, depending upon acclimation temperatures tested. The pH in river water was more influential than temperature in controlling the amount of HOCl present within the FRC at each TRC exposure. Avoidance responses by fish to CRC concentrations were either equal to or greater than TRC exposures and were dependent upon the ammonia-N content. Chloramine and FRC (specifically the HOCl fraction) have been reported to have different mechanisms of toxicity, which offered possible explanations for the differences observed in avoidance behavior. Chlorine residuals discharged from the Glen Lyn power plant in previous years have exceeded the LC₅₀ values reported for many species, although no major fish kills from chlorine have been documented. Behavioral avoidance responses by fish to potentially lethal chlorinated discharges in aquatic receiving systems may be a major mechanism of these populations in adapting to or interacting within these industrially influenced environments.     

Risk management is not enough: a conceptual model for resilience and adaptation-based vulnerability assessments

The US government has focused considerable attention on enhancing our society’s ability to protect critical systems and services from disruptive events. Over the past decade, federal agencies have bolstered their efforts to identify and minimize threats using traditional risk-based approaches such as continuity of operations and disaster risk reduction processes. However, these valuable risk identification and management tools are limited because they rely upon foreseeable factor analyses of steady-state systems with predictable hazard frequencies and severities. In assessing the capability of complex adaptive systems to cope with disruptions, an overemphasis upon engineering resilience through risk management and planning for what is predictable may cloud or detract from our efforts to better understand a system’s emergent capabilities to withstand disruptions that are unforeseeable. This article contends that augmenting traditional risk approaches through the incorporation of methodologies grounded in socio-ecological system (SES) resilience principles offers a potential avenue for improving our agencies’ abilities to assess and manage both known and unknown risks. We offer a notional rationale for broadening our examination of system vulnerabilities and present a conceptual model that combines engineering and SES resilience paradigms to facilitate the identification, assessment, and management of system vulnerabilities. The Military Installation Resilience Assessment model described herein applies risk and resilience principles to evaluate whole systems, focusing on interconnections and their functionality in facilitating response and adaptation.     

A Comparison of Bayesian Methods for Uncertainty Analysis in Hydraulic and Hydrodynamic Modeling

We evaluate and compare the performance of Bayesian Monte Carlo (BMC), Markov chain Monte Carlo (MCMC), and the Generalized Likelihood Uncertainty Estimation (GLUE) for uncertainty analysis in hydraulic and hydrodynamic modeling (HHM) studies. The methods are evaluated in a synthetic 1D wave routing exercise based on the diffusion wave model, and in a multidimensional hydrodynamic study based on the Environmental Fluid Dynamics Code to simulate estuarine circulation processes in Weeks Bay, Alabama. Results show that BMC and MCMC provide similar estimates of uncertainty. The posterior parameter densities computed by both methods are highly consistent, as well as the calibrated parameter estimates and uncertainty bounds. Although some studies suggest that MCMC is more efficient than BMC, our results did not show a clear difference between the performance of the two methods. This seems to be due to the low number of model parameters typically involved in HHM studies, and the use of the same likelihood function. In fact, for these studies, the implementation of BMC results simpler and provides similar results to MCMC. The results of GLUE are, on the other hand, less consistent to the results of BMC and MCMC in both applications. The posterior probability densities tend to be flat and similar to the uniform priors, which can result in calibrated parameter estimates centered in the parametric space.     

Intervention of pentoxifylline on silica-induced inflammatory reaction and apoptosis

Pentoxifylline (PTX) is a clinically used drug mainly for peripheral circulation improvement. This drug also possesses potent anti-inflammatory effects and was found to inhibit acute lung injury induced by chemical agents in animal models. Since it is also a potential apoptosis enhancer, this study was designed to examine the influence of PTX on silica-induced lung inflammation and pulmonary leucocyte apoptosis. Male Wistar rats were intratracheally instilled with either silica dust suspension or saline and intraperitoneally injected with saline or PTX. These treatments continued for six weeks and all rats were then sacrificed to obtain bronchoalveolar lavage cells and lavage fluid. Data demonstrated that PTX attenuated silica-induced lung injury in the rat model and this attenuation may possibly be attributed to its role in the enhancement of pulmonary apoptosis. As a known clinically safe drug, PTX may thus have potential use in the treatment of human silicosis.     

Understanding the sources and composition of the incremental excess of fine particles across multiple sampling locations in one air shed

Well-designed health studies and the development of effective regulatory policies need to rely on an understanding of the incremental differences in particulate matter concentrations and their sources. Although only a limited number of studies have been conducted to examine spatial differences in sources to particulate matter within an air shed, routine monitoring data can be used to better understand these differences. Measurements from the US EPA Chemical Speciation Network （CSN） collected between 2002-2008 were analyzed to demonstrate the utility of regulatory data across three sites located within 100 km of each other. Trends in concentrations, source contribution, and incremental excesses across three sites were investigated using the Positive Matrix Factorization model. Similar yearly trends in chemical composition were observed across all sites, however, excesses of organic matter and elemental carbon were observed in the urban center that originated from local emissions of mobile sources and biomass buming. Secondary sulfate and secondary nitrate constituted over half of the PM2.5 with no spatial differences observed across sites. For these components, the excess of emissions from industrial sources could be directly quantified. This study demonstrates that CSN data from multiple sites can be successfully used to derive consistent source profiles and source contributions for regional pollution, and that CSN data can be used to quantify incremental differences in source contributions of across these sites. The analysis strategy can be used in other regions of the world to take advantage of existing ambient particulate matter monitoring data to better the understanding of spatial differences in source contributions within a given air shed.