NUTRIENT LOADING ASSESSMENT IN THE ILLINOIS RIVER USING A SYNTHETIC APPROACH1

ABSTRACT: A synthetic relationship is developed between nutrient concentrations and discharge rates at two river gauging sites in the Illinois River Basin. Analysis is performed on data collected by the U.S. Geological Survey (USGS) on nutrients in 1990 through 1997 and 1999 and on discharge rates in 1988 through 1997 and 1999. The Illinois River Basin is in western Arkansas and northeastern Oklahoma and is designated as an Oklahoma Scenic River. Consistently high nutrient concentrations in the river and receiving water bodies conflict with recreational water use, leading to intense stakeholder debate on how best to manage water quality. Results show that the majority of annual phosphorus (P) loading is transported by direct runoff, with high concentrations transported by high discharge rates and low concentrations by low discharge rates. A synthetic relationship is derived and used to generate daily phosphorus concentrations, laying the foundation for analysis of annual loading and evaluation of alternative management practices. Total nitrogen (N) concentration does not have as clear a relationship with discharge. Using a simple regression relationship, annual P loadings are estimated as having a root mean squared error (RMSE) of 39.8 t/yr and 31.9 t/yr and mean absolute percentage errors of 19 percent and 28 percent at Watts and Tahlequah, respectively. P is the limiting nutrient over the full range of discharges. Given that the majority of P is derived from Arkansas, management practices that control P would have the most benefit if applied on the Arkansas side of the border.     

Conservation implications of physiological carry‐over effects in bats recovering from white‐nose syndrome

Although it is well documented that infectious diseases can pose threats to biodiversity, the potential long‐term consequences of pathogen exposure on individual fitness and its effects on population viability have rarely been studied. We tested the hypothesis that pathogen exposure causes physiological carry‐over effects with a pathogen that is uniquely suited to this question because the infection period is specific and time limited. The fungus Pseudogymnoascus destructans causes white‐nose syndrome (WNS) in hibernating bats, which either die due to the infection while hibernating or recover following emergence from hibernation. The fungus infects all exposed individuals in an overwintering site simultaneously, and bats that survive infection during hibernation clear the pathogen within a few weeks following emergence. We quantified chronic stress during the active season, when bats are not infected, by measuring cortisol in bat claws. Free‐ranging Myotis lucifugus who survived previous exposure to P. destructans had significantly higher levels of claw cortisol than naïve individuals. Thus, cryptic physiological carry‐over effects of pathogen exposure may persist in asymptomatic, recovered individuals. If these effects result in reduced survival or reproductive success, they could also affect population viability and even act as a third stream in the extinction vortex. For example, significant increases in chronic stress, such as those indicated here, are correlated with reduced reproductive success in a number of species. Future research should directly explore the link between pathogen exposure and the viability of apparently recovered populations to improve understanding of the true impacts of infectious diseases on threatened populations.     

Assessing the Potential for Salmon Recovery via Floodplain Restoration: A Multitrophic Level Comparison of Dredge-Mined to Reference Segments

Pre-restoration studies typically focus on physical habitat, rather than the food-base that supports aquatic species. However, both food and habitat are necessary to support the species that habitat restoration is frequently aimed at recovering. Here we evaluate if and how the productivity of the food-base that supports fish production is impaired in a dredge-mined floodplain within the Yankee Fork Salmon River (YFSR), Idaho (USA); a site where past restoration has occurred and where more has been proposed to help recover anadromous salmonids. Utilizing an ecosystem approach, we found that the dredged segment had comparable terrestrial leaf and invertebrate inputs, aquatic primary producer biomass, and production of aquatic invertebrates relative to five reference floodplains. Thus, the food-base in the dredged segment did not necessarily appear impaired. On the other hand, we observed that off-channel aquatic habitats were frequently important to productivity in reference floodplains, and the connection of these habitats in the dredged segment via previous restoration increased invertebrate productivity by 58%. However, using a simple bioenergetic model, we estimated that the invertebrate food-base was at least 4× larger than present demand for food by fish in dredged and reference segments. In the context of salmon recovery efforts, this observation questions whether additional food-base productivity provided by further habitat restoration would be warranted in the YFSR. Together, our findings highlight the importance of studies that assess the aquatic food-base, and emphasize the need for more robust ecosystem models that evaluate factors potentially limiting fish populations that are the target of restoration.     

Recent Electrostatic Precipitator Experience with Ammonia Conditioning of Power Boiler Flue Gases

Motivated by heightened recent interest, Koppers Co. has been experimenting with ammonia conditioning of power boiler flue gases for the purpose of improving the precipitability of the emitted fly ash. Chemical reactions resulting from ammonia injection are postulated. Measurements on three pulverized coal and two cyclone fired boilers, all of which emit acidic ash, are described. In all five cases, considerable but varying, increase in precipitator power input and collection efficiency resulted when gaseous ammonia in the amount of 1 5 ppm was injected between the economizer and air preheater. The conditioned fly ash showed decreased acidity and inconsistent change in electrical resistivity. Unless air heater temperatures were unusually high (>400°F), tendency of the air heater to plug was an additional, but unwanted, result. At one station with high air heater outlet temperature ammonia injection has been adopted as a permanent solution to community pressure for reduction of stack discharge. Ammonia injection downstream of the air heater produced no effect. Future plans are presented to continue the program beyond results described here.     

An Evaluation of Techniques to Control Problem Bird Species on Landfill Sites

Birds feeding on landfill sites cause problems in terms of nuisance to neighbors, flight safety, a threat to public health, and affecting the day to day site operation. A number of control measures exist to deter problem species; however, research into their effectiveness across sites and for multiple species has been limited. We use a modeling approach in order to assess the effectiveness of nine techniques — pyrotechnics, hand-held distress calls, static distress calls, blank ammunition, a combination of blank and lethal use of ammunition, the use of falcons, the use of hawks, wailers and helium-filled bird-scaring kites — at deterring three commonly recorded species — the Black-headed Gull (Larus ridibundus), the Herring Gull (Larus argentatus) and the Lesser Black-backed Gull (Larus fuscus) — from six landfill sites across the United Kingdom. The use of distress calls, falconry, and combinations of lethal and nonlethal use of ammunition were the most effective techniques for initially deterring birds from these sites. However, when habituation is considered, there is a clear difference between techniques such as falconry, which have a lethal aspect and may act to reinforce the deterrence, and the use of techniques such as distress calls, which do not. However there are problems related to legislation and public perception when lethal techniques are used.     

Development and Parameterization of a Rain- and Fire-driven Model for Exploring Elephant Effects in African Savannas

We describe the development and parameterization of a grid-based model of African savanna vegetation processes. The model was developed with the objective of exploring elephant effects on the diversity of savanna species and structure, and in this formulation concentrates on the relative cover of grass and woody plants, the vertical structure of the woody plant community, and the distribution of these over space. Grid cells are linked by seed dispersal and fire, and environmental variability is included in the form of stochastic rainfall and fire events. The model was parameterized from an extensive review of the African savanna literature; when available, parameter values varied widely. The most plausible set of parameters produced long-term coexistence between woody plants and grass, with the tree–grass balance being more sensitive to changes in parameters influencing demographic processes and drought incidence and response, while less sensitive to fire regime. There was considerable diversity in the woody structure of savanna systems within the range of uncertainty in tree growth rate parameters. Thus, given the paucity of height growth data regarding woody plant species in southern African savannas, managers of natural areas should be cognizant of different tree species growth and damage response attributes when considering whether to act on perceived elephant threats to vegetation.     

Nitrous oxide (N2O) emissions from waste and biomass to energy plants.

Following the Kyoto protocol with respect to reducing emissions of greenhouse gases emissions, and EU energy policy and sustainability in waste management, there has been an increased interest in the reduction of emissions from waste disposal operations. From the point of view of nitrous oxide (N2O) emissions, waste incineration and waste co-combustion are very acceptable methods for waste disposal. In order to achieve very low N2O emissions from waste incineration, particularly for waste with higher nitrogen content (e.g. sewage sludge), two factors are important: temperature of incineration over 900 degrees C and avoiding the selective non-catalytic reduction (SNCR) de-NO(X) method based on urea or ammonia treatments. The more modern selective catalytic reduction (SCR) systems for de-NO(X) give rise to negligible sources of N2O.     

From Siting Principles to Siting Practices: A Case Study of Discord among Trust,Equity and Community Participation

This paper contributes to the noxious facilities siting literature by exploring some implications of adhering to some recommended principles and practices for competent siting. Through a qualitative case study of a landfill siting process in Peel (Ontario, Canada) three principles are critically assessed: trust; equity; and community participation. While laudable notions in principle, in practice they can impact each other in important ways which can (potentially) undermine the siting process. These impacts result mainly from the failure to achieve meaningful goals associated with one principle (e.g. community participation) which can exacerbate problems achieving goals associated with other principles (e.g. trust). The resulting discord can be further aggravated by the snowballing of adverse effects over time. In particular, practices for achieving trust and equity were adversely linked, as were the relationships between spatial equity and procedural equity and interregional and intraregional equity. These adverse synergisms were linked together with ineffective community participation which brought the process to a halt. Siting inertia (a process momentum difficult to redirect) and an inflexible siting context contributed to these conflicts. Implications for siting and further research are discussed.     

Trends in Wildlife Management and the Appropriateness of Australian University Training

Abstract: That the greatest challenges in conservation are often not technical but rather economic or sociological has been expressed for at least the last 20 years. This raises the question of whether the training offered to tomorrow's conservation practitioners prepares them sufficiently to deal with the human dimensions of conservation. We analyzed 747 papers from seven wildlife management and conservation biology journals to determine the trends in this area of conservation management between 1985 and 1995. We found that over that time the emphasis stayed on single-species issues with a science focus, but there was a marked shift toward conservation biology issues, management-oriented research, and discussion of economic and social factors relevant to management. We also examined the handbooks of 11 Australian universities to analyze the content of 439 compulsory subjects in 12 degrees that we judged could produce wildlife managers. More than 68% of subjects were from a basic science or technology discipline, 16% from resource management, and only 13% from economics, humanities, communications, or planning. Thus, many of the skills required by contemporary wildlife managers must be learned in postgraduate training or on the job. Much of the undergraduate training syllabus, in Australia at least, does not reflect trends in the practice of wildlife management today and will not provide tomorrow's managers with the range of disciplinary understanding required. We were able, however, to identify three types of undergraduate training—ecological system managers, environmental managers, and human system managers—and we found that the curricula in human-system management contained increased emphasis on socioeconomic issues relevant to management.