Self-Organizing Maps for Integrated Environmental Assessment of the Mid-Atlantic Region

A new method has been developed to perform environmental assessment at regional scale. This involves a combination of a self-organizing map (SOM) neural network and principal component analysis (PCA). The method is capable of clustering ecosystems in terms of environmental conditions and suggesting relative cumulative environmental impacts of multiple factors across a large region. Using data on land-cover, population, roads, streams, air pollution, and topography of the Mid-Atlantic region, the method was able to indicate areas that are in relatively poor environmental condition or vulnerable to future deterioration. Combining the strengths of SOM with those of PCA, the method offers an easy and useful way to perform a regional environmental assessment. Compared with traditional clustering and ranking approaches, the described method has considerable advantages, such as providing a valuable means for visualizing complex multidimensional environmental data at multiple scales and offering a single assessment or ranking needed for a regional environmental assessment while still facilitating the opportunity for more detailed analyses.     

A proposed formal structure for assessing bear-human encounters

A formal model for the interaction of bear and hiker populations in national parks is developed. A number of alternative interactive scenarios are identified and some specific cases explored in detail. Some examples of the insights to be gained by the use of such a formal structure by park managers charged with the dual mandate of preservation of fauna and provision of safe recreational opportunities are presented. The entire problem is then discussed within the context of the more general tragedy of the commons problem.     

Effects of methyl-, phenyl-, ethylmercury and mercurychlorid on immune cells of harbor seals （Phoca vitulina）

Mercury (Hg) is present in the marine environment as a natural metal often enhanced through human activities. Depending on its chemical form, Hg can cause a wide range of immunotoxic e ects. In this study, the influence of methyl-, ethyl- and phenylmercury as well as mercurychloride on immune functions was evaluated. Two parameters of cellular immunity, proliferation and mRNA cytokine expression of interleukin-2, -4, and transforming growth factor , were investigated in harbor seal lymphocytes after in vitro exposure to Hg compounds. While all Hg compounds had a suppressive e ect on proliferation, di erences between juvenile and adult seals were found. Lymphocytes from juveniles showed a higher susceptibility to the toxic e ect compared to lymphocytes from adults. Furthermore, the degree of inhibition of proliferation varied among the four Hg compounds. The organic compounds seem to be more immunotoxic than the inorganic compound. Finally, for the cytokine expression of methylmercury-incubated lymphocytes, timedependent changes were observed, but no dose-dependency was found. Marine mammals of the North Sea are burdened with Hg, and lymphocytes of harbor seals may be functionally impaired by this metal. The present in vitro study provides baseline information for future studies on the immunotoxic e ects of Hg on cellular immunity of harbor seals.     

Genetic identity determines risk of post-settlement mortality of a marine fish

Longitudinal sampling of four cohorts of Neopomacentrus filamentosus, a common tropical damselfish from Dampier Archipelago, Western Australia, revealed the evolution of size structure after settlement. Light traps collected premetamorphic individuals from the water column ("settlers") to establish a baseline for each cohort. Subsequently, divers collected benthic juveniles ("recruits") at 1-3-month intervals to determine the relative impacts of post-settlement mortality during the first three months. Growth trajectories for individual fish were back-calculated from otolith records and compared with nonlinear mixed-effects models. Size-selective mortality was detected in all cohorts with the loss of smaller, slower growing individuals. Three months after settlement, recruits showed significantly faster growth as juveniles, faster growth as larvae, and larger sizes as hatchlings. The timing and intensity of post-settlement selection differed among cohorts and was correlated with density at settlement. The cohort with the greatest initial abundance experienced the strongest selective mortality, with most of this mortality occurring between one and two months after settlement when juveniles began foraging at higher positions in the water column. Significant genetic structure was found between settlers and three-month-old recruits in this cohort as a result of natural selection that changed the frequency of mtDNA haplotypes measured at the control region. The extent of this genetic difference was enlarged or reduced by artificially manipulating the intensity of size-based selection, thus establishing a link between phenotype and haplotype. Sequence variation in the control region of the mitochondrial genome has been linked to mitochondrial efficiency and weight gain in other studies, which provides a plausible explanation for the patterns observed here.     

Remembering the Past,Anticipating the Future: Community Learning and Adaptation Discourse in Media Commemorations of Catastrophic Wildfires in Colorado

Wildfire may be the clearest example to date of a socio-natural hazard that is being exacerbated by climate change, making wildfire an essential lens through which to investigate learning and adaptation in the Anthropocene. Here, we study discourse about simultaneous and recurring catastrophic wildfires in Colorado newspapers. We find that the wildfires’ anniversaries served as opportunities for critical reflection on hazard causality and mitigation in local media, particularly the first anniversary and especially for a community that experienced two catastrophic wildfires in a row. Two mediated prospective memory practices—invoking hindsight as foresight and recognizing a new normal—contributed to this discourse. However, learning and adaptation discourse faded in local media at later anniversaries. These findings contribute to learning and adaptation scholarship by connecting the concept of mediated prospective memory to disaster-related media studies and attending to the intricacies of anniversary commemoration under circumstances of simultaneous and recurring disasters.     

Juggling Land Retirement Objectives on an Agricultural Landscape: Coordination, Conflict, or Compromise?

Strategic land retirement in agricultural settings has been used as one way to achieve a combination of social objectives, which include ameliorating water quality problems and enhancing existing systems of wildlife habitat. This study uses a simulation model operating on a virtual landscape, along with the compromise programming method, to illustrate the implications of alternative weighting schemes for the long-term performance of the landscape toward various objectives. The analysis suggests that particular spatial patterns may be related to how various objectives are weighted. The analysis also illustrates the inevitable trade-offs among objectives, although it may be tempting to present retirement strategies as “win-win.”     

Pyrethrins and piperonyl butoxide residues on potato leaves and in soil under field conditions.

Residues of pyrethrin-I (Py-I) and pyrethrin-II (Py-II), the major insecticidal components of the pyrethrum daisy (Tanacetum cinerariifolium) as well as residues of piperonyl butoxide (PBO, a pyrethrum synergist) were determined in soil and on potato foliage grown under field conditions. A pyrethrum formulation (Multi-Purpose Insecticide) containing the three active ingredients was sprayed twice at the rate of 6 lbs of formulated product.acre(-1) ( 5.4 and 27.2 g A.I. of pyrethrin and PBO, respectively) on potato foliage during the growing season. In soil, three management practices (yard waste compost, grass filter strips, and a no mulch treatment) were used to study the impact of surface soil characteristics on the amount of pyrethrins (Pys) and PBO retained in soil. Soil samples and potato leaves were collected at different time intervals after spraying. Samples were purified and concentrated using solid-phase extraction columns containing C18-Octadecyl bonded silica. Residues were quantified by high-performance liquid chromatograph equipped with a UV detector. The first spray resulted in mean initial deposits of 0.18, 0.40, and 0.99 microg.g(-1) potato leaves for Py-I, Py-II, and PBO, respectively. Residues in soil were higher in compost treatments compared to no mulch treatments.     

Recommended Design for More Accurate Duplication of Natural Conditions in Salt Marsh Creation

Construction of 653 ha of salt marsh habitat from dredged material near the Aransas National Wildlife Refuge, Texas, has been proposed, with the goal of increasing the area of habitat available to endangered whooping cranes (Grus americana). We assessed prototype created wetlands, and their similarity to natural reference sites, in terms of topography, vegetation, and hydrology. The created sites were steeply sloped relative to natural sites and were dominated by monotypic stands of Spartina alterniflora. Natural sites were dominated by vegetation more tolerant of desiccation and hypersalinity and by unvegetated salt pans. Differences in vegetation communities and distributions of habitat types resulted from efforts to enhance habitat diversity in created marsh cells through manipulation of marsh topography. However, the scale at which this diversity occurred in natural marsh of the study area was not considered. When constructing wetlands in cellular configurations, we recommend creation of large complexes of adjoining, hydrologically linked, cells wherein the desired habitat diversity is created at the scale of the entire complex, rather than within a single cell. Suggested design modifications would increase the similarity of created marshes to natural reference sites, potentially improving habitat function.     

Fiberboard plant emissions control using a silent discharge plasma

A silent discharge plasma reactor was constructed to test a potential industrial application for controlling volatile organic carbon emission from fiberboard manufacturing plants. The reactor consisted of a cylindrical single barrier dielectric barrier discharge cell connected to a high‐voltage ac power supply. Various concentrations of turpene in air were introduced into the reactor under dry and wet conditions. The destruction removal efficiencies (DRE) were monitored using a gas chromatograph mass spectrometer (GCMS) and the concentrations of carbon dioxide generated from the oxidation ofturpene were monitored using a Fourier Transform Infrared Spectrometer (FTIR). It was found that 90 percent of the turpenes could be removed at modest energy densities and that adding water to the gas mix greatly enhanced the destruction of the turpenes. However, even at high energy densities, the oxidation of turpenes did not completely form carbon dioxide. The results suggest that the Silent Discharge Plasma (SDP) system can be used to control the emission of volatile organic compounds (VOCs) from fiberboard plants, but that further testing is needed to limit the emission of carbon monoxide.