A better future for the uplands — a planning critique

The Countryside Commission's report A Better Future for the Uplands puts forward a new strategy for public intervention in the uplands of England and Wales. The aim of the report is to integrate rural policies and to promote higher environmental priorities in rural areas. This paper considers the degree to which the report is successful in planning to achieve these ends. The paper is specifically concerned with the planning methodology on which the report is based. The paper argues for an approach to rural planning which permits the consideration of more radical solutions to rural problems, along with the application of a more systematic planning methodology, in order to assist in the choice of an appropriate direction for planned change.     

Mineralogical characteristics and transformations during long-term operation of a zerovalent iron reactive barrier

Design and operation of Fe0 permeable reactive barriers (PRBs) can be improved by understanding the long-term mineralogical transformations that occur within PRBs. Changes in mineral precipitates, cementation, and corrosion of Fe0 filings within an in situ pilot-scale PRB were examined after the first 30 months of operation and compared with results of a previous study of the PRB conducted 15 months earlier using X-ray diffraction and scanning electron microscopy employing energy dispersive X-ray and backscatter electron analyses. Iron (oxy)hydroxides, aragonite, and maghemite and/or magnetite occurred throughout the cores collected 30 mo after installation. Goethite, lepidocrocite, mackinawite, aragonite, calcite, and siderite were associated with oxidized and cemented areas, while green rusts were detected in more reduced zones. Basic differences from our last detailed investigation include (i) mackinawite crystallized from amorphous FeS, (ii) aragonite transformed into calcite, (iii) akaganeite transformed to goethite and lepidocrocite, (iv) iron (oxy)hydroxides and calcium and iron carbonate minerals increased, (v) cementation was greater in the more recent study, and (vi) oxidation, corrosion, and disintegration of Fe0 filings were greater, especially in cemented areas, in the more recent study. If the degree of corrosion and cementation that was observed from 15 to 30 mo after installation continues, certain portions of the PRB (i.e., up-gradient entrance of the ground water to the Fe0 section of the PRB) may last less than five more years, thus reducing the effectiveness of the PRB to mitigate contaminants.     

Impacts of disturbance from construction work on the densities and feeding behavior of waterbirds using the intertidal mudflats of Cardiff Bay,UK

The impact of disturbance from construction work around Cardiff Bay, south Wales, on the densities and feeding behavior of seven waterbird species was studied over an 11-year period. Construction of a barrage across the mouth of the bay has subsequently resulted in its impoundment; other major works included the construction of a bridge carrying a divided highway. Construction work disturbance significantly reduced the densities of five species—green-winged teal (Anas crecca), Eurasian oystercatcher (Haematopus ostralegus), dunlin (Calidris alpina), Eurasian curlew (Numenius arquata), and common redshank (Tringa totanus)—on adjacent intertidal mudflats, and thus the overall carrying capacity of the bay. Construction work also reduced the feeding activity of Eurasian oystercatcher, dunlin, and common redshank on these mudflats. The possible impact of the loss of birds from these mudflats upon the populations that the bay supported is discussed. Evidence from other local studies suggests that the displacement of common redshank from these mudflats did not contribute to a decline in this species.     

Defining acceptable conditions in wilderness

The limits of acceptable change (LAC) planning framework recognizes that forest managers must decide what indicators of wilderness conditions best represent resource naturalness and high-quality visitor experiences and how much change from the pristine is acceptable for each indicator. Visitor opinions on the aspects of the wilderness that have great impact on their experience can provide valuable input to selection of indicators. Cohutta, Georgia; Caney Creek, Arkansas; Upland Island, Texas; and Rattlesnake, Montana, wilderness visitors have high shared agreement that littering and damage to trees in campsites, noise, and seeing wildlife are very important influences on wilderness experiences. Camping within sight or sound of other people influences experience quality more than do encounters on the trails. Visitors’ standards of acceptable conditions within wilderness vary considerably, suggesting a potential need to manage different zones within wilderness for different clientele groups and experiences. Standards across wildernesses, however, are remarkably similar.     

ASSESSMENT OF RESTORED RWERINE HABITAT USING RCHARC1

ABSTRACT: The Riverine Community Habitat Assessment and Restoration Concept (RCHARC) was developed to integrate habitat enhancement into the stream restoration process. RCHARC assumes that aquatic habitat quality is closely related to hydraulic diversity based upon a “comparison standard” reach approach to stream restoration. A Beta test was performed by applying the RCHARC process to Rapid Creek in Rapid City, South Dakota. Standard and restored stream reaches were selected and data were collected. A comparison of field data and velocity-depth distributions indicated that the restored stream closely replicated the standard reach. The RCHARC methodology has the potential to assess habitat quality for planned comparison reaches and indicate the level of success resulting from restoration.     

Teams in social insects: group retrieval of prey by army ants (Eciton burchelli,Hymenoptera: Formicidae)

Summary Eciton burchelli workers frequently form groups to retrieve large prey items. Such groups have a definite structure. There is a constant relationship between total ant dry weight and prey item dry weight for both individual porters and groups, and this relation is such that a larger weight of ant or ants can carry disproportionately heavy items. Furthermore, all prey items are carried at a standard retrieval speed. This means that groups are superefficient; they can carry items that are so large that if they were fragmented the original members of the group would be unable to carry all the fragments. Groups also have a distinct caste distribution. There is a significant tendency for each group to have a single submajor, the specialist porter caste in Eciton burchelli. These findings which were verified by experiments suggest that groups fulfill the criteria of efficient teams. The biomechanics are proposed to explain the superefficiency of groups. The organization of co-operation is considered as is the role of teams in the economy of these societies. Colony caste profiles can only be understood by examining the role of teams which form a plastic supercaste.     

Measurement of ultrafine particle size distributions from coal-, oil-, and gas-fired stationary combustion sources

Currently, we have limited knowledge of the physical and chemical properties of emitted primary combustion aerosols and the changes in those properties caused by nucleation, condensation growth of volatile species, and particle coagulations under dilution and cooling in the ambient air. A dilution chamber was deployed to sample exhaust from a pilot-scale furnace burning various fuels at a nominal heat input rate of 160 kW/h(-1) and 3% excess oxygen. The formation mechanisms of particles smaller than 420 nm in electrical mobility diameter were experimentally investigated by measurement with a Scanning Mobility Particle Sizer (SMPS) as a function of aging times, dilution air ratios, combustion exhaust temperatures, and fuel types. Particle formation in the dilution process is a complex mixture of nucleation, coagulation, and condensational growth, depending on the concentrations of available condensable species and solid or liquid particles (such as soot, ash) in combustion exhausts. The measured particle size distributions in number concentrations measured show peaks of particle number concentrations for medium sulfur bituminous coal, No. 6 fuel oil, and natural gas at 40-50 nm, 70-100 nm, and 15-25 nm, respectively. For No. 6 fuel oil and coal, the particle number concentration is constant in the range of a dilution air ratio of 50, but the number decreases as the dilution air ratio decreases to 10. However, for natural gas, the particle number concentration is higher at a dilution air ratio of 10 and decreases at dilution air ratios of 20-50. At a dilution air ratio of 10, severe particle coagulation occurs in a relatively short time. Samples taken at different combustion exhaust temperatures for these fuel types show higher particle number concentrations at 645 K than at 450 K. As the aging time of particles increases, the particles increase in size and the number concentrations decrease. The largest gradient of particle number distribution occurs within the first 10 sec after dilution but shows only minor differences between 10 and 80 sec. The lifetimes of the ultrafine particles are relatively short, with a scale on the order of a few seconds. Results from this study suggest that an aging time of 10 sec and a dilution air ratio of 20 are sufficient to obtain representative primary particle emission samples from stationary combustion sources.     

Chemical Warfare Materiel: Unique Regulatory Issues

In those states that have not included CWM as hazardous materials in their RCRA programs, the RCRA requirements for management of hazardous waste would not strictly apply to any of the CWM. The Army has historically implemented procedures requiring that chemical warfare agents be managed as RCRA hazardous waste regardless of the concentration, physical form, or configuration of the agent. Such application of strict hazardous waste requirements to management of potentially nonhazardous CWM can result in remedial costs well out of proportion to potential human health and environmental benefits. Recent development of chronic toxicity values for the CWM has opened the door for development of cleanup and waste management standards for waste streams or media containing small residual amounts of CWM. Implementation of this health-based approach to management of CWM remediation wastes may, in part, help to reduce potentially unnecessary hazardous waste management costs for the nonhazardous CWM.