Description and evaluation of a model of deposition velocities for routine estimates of dry deposition over North America. Part II: review of past measurements and model results

Numerical sensitivity tests and four months of complete model runs have been conducted for the Routine Deposition Model (RDM). The influence of individual model inputs on dry deposition velocity as a function of land-use category (LUC) and pollutant (SO₂, O₃, SO²⁻₄ and HNO₃) were examined over a realistic range of values for solar radiation, stability and wind speed. Spatial and temporal variations in RDM deposition velocity (V_d) during June – September 1996 time period generated using meteorological input from a mesoscale model run at 35 km resolution over north-eastern North America were also examined. Comparison of RDM V_d values to a variety of measurements of dry deposition velocities of SO₂, O₃, SO²⁻₄ and NHO₃ that have been reported in the literature demonstrated that RDM produces realistic results. Over northeastern NA RDM monthly averaged dry deposition velocities for SO₂ vary from 0.2 to 3.0 cm s⁻¹ with the highest deposition velocities over water surfaces. For O₃, the monthly averaged dry deposition velocities are from 0.05 to 1.0 cm s⁻¹ with the lowest values over water surfaces and the highest over forested areas. For HNO₃, the monthly averaged dry deposition velocities have the range of 0.5 to 6 cm s⁻¹, with the highest values for forested areas. For SO²⁻₄, they range from 0.05–1.5 cm s⁻¹, with the lowest values over water and the highest over forest. The monthly averaged dry deposition velocities for SO₂ and O₃ are higher in the growing season compared to the fall, but this behaviour is not apparent for HNO₃ and sulphate. In the daytime, the hourly averaged dry deposition velocities for SO₂, O₃, SO²⁻₄ and HNO₃ are higher than that in the nighttime over most of the vegetated area. The diurnal variation is most evident for surfaces with large values for leaf area index (LAI), such as forests. Based on the results presented in this paper, it is concluded that RDM V_d values can be combined with measured air concentrations over hourly, daily or weekly periods to determine dry deposition amounts and with wet deposition measurements to provide seasonal estimates of total deposition and estimates of the relative importance of dry deposition.     

Animal Rights: Autonomy and Redundancy

Even if animal liberation were to be adopted, would rights for animals be redundant – or even deleterious? Such an objection, most prominently voiced by L. W. Sumner and Paul W. Taylor, is misguided, risks an anthropocentric and anthropomorphic conception of autonomy and freedom, overly agent-centered rights conceptions, and an overlooking of the likely harmful consequences of positing rights for humans but not for nonhuman animals. The objection in question also stems from an overly pessimistic construal of autonomy-infringements thought to result from extending rights to animals, and also, of confusions that supposedly may ensue from ascribing animal rights. Whether or not a case for animal liberation and/or animal rights can cogently be made, the redundancy-or-worse objection to animal rights need pose no barrier.     

Economic Valuation of the Non-use Attributes of a Wetland: A Case-study for Lake Kerkini

Wetlands are an environmental feature which deliver a variety of market and non-market goods and services. Established environmental economic theory separates the value of these goods and services into direct-use values, indirect-use values and non-use values. Given appreciation of all three, measurements can be derived to demonstrate the amount of public money that it may be feasible to allocate to the sustainable management of wetlands. However, in many cases, non-use values are ignored and the total economic value of wetlands can be severely undervalued. As a result, inadequate resources are fed into their management and environmental degradation occurs due to inappropriate commercial exploitation of the natural resource. Lake Kerkini, in northern Greece, is one such wetland area threatened by undervaluation and overexploitation for commercial purposes, and a resource whose management would benefit from the realization of non-use values. This study therefore uses the contingent valuation method to place a value on the non-use attributes of Lake Kerkini. It also examines the relationship between the revealed non-use values and the distance people live from the lake, highlights the personal characteristics which appear important in determining total willingness to pay and breaks total non-use value down into its component parts to suggest the most important non-use elements. The paper concludes that sustainable management of the lake is justified and provides evidence that substantial public monies are potentially available to protect and enhance the environmental value of the resource.     

The economics of climate change in agriculture

This paper presents a conceptual frameworkof the impact of climate change onagriculture. It assumes that climatechange will result in a fertilizationeffect and a shift of agro-ecologicalconditions away from the Equator towardsthe Poles. The agro-ecological shift islikely to reduce yield because of reducedacreage and the fertilization effect willincrease yield. The aggregate effectdepends on whichever of the two dominates. The overall effect of climate change may beless significant than its distributionaleffects and the results are consistentwith previous empirical studies. Theimpact of climate change depends on itspace. Faster changes in climate willresult in higher cost. The assessment ofthe cost has to consider that climatechange is a dynamic phenomenon that mayrequire continuous adjustment. Environmental regulation that emphasizesconservation may increase cost ofadjustment and environmental policiesshould emphasize adaptation andflexibility.     

Comparison of methods for determining key marine areas from tracking data

There is an urgent need to identify key marine areas for conservation, particularly in the high seas. A range of techniques have been applied to tracking data from higher predators, particularly seabirds and pinnipeds, to determine the areas of greatest use. This study compared three commonly used methods—kernel, first-passage time and state-space modelling—and a new approach, minimum displacement rate, for the analysis of data from the wandering albatross Diomedea exulans of Bird Island, South Georgia, tracked during the chick-rearing period. Applied to a single track, these four models identified similar marine areas as important. The greatest similarity in areas identified occurred when model assumptions were shared (such as slow speed indicating spatial preference) even when methods modelled these assumptions differently (e.g. Bayesian inference versus cumulative density surface). A gridded overlap approach applied to all tracks revealed core areas not apparent from results of any single analysis. The gridded approach also revealed spatial overlap between methods based on different assumptions (e.g. minimum displacement rate and kernel analysis) and between individuals. Although areas identified as important by kernel and first-passage time analysis of a single track were biased towards resting locations during darkness, this does not negate the requirement for their protection. Using the gridded overlap approach, two distinct core regions were identified for the wandering albatross; one close to the breeding colony and another 800 km to the North–West in the high seas. This convenient and pragmatic approach could be applied to large data sets and across species for the identification of a network of candidate marine protected areas in coastal and pelagic waters.     

Physiological tolerance predicts species composition at different scales in a barnacle guild

This study examined how the species composition of an intertidal barnacle guild varied according to physical gradients in the environment at small scales governed by microclimates, medium scales of wave exposure and large scales of latitude. Barnacle distributions at small and medium scales were sampled in Ireland between 51°29′ and 52°44′N and 6°50′ and 10°08′W. Sampling on European shores spanned ~18° latitude from 37°05′ to 55°16′N. Barnacle surveys mainly took place in 2003–2004. An index of wave fetch was calculated along the wave exposure gradient using a digital coastline-based model that was supported by a biological exposure scale. A ‘dryness’ index was defined according to mean monthly wind speed, fetch along the average wind direction and mean monthly air or sea surface temperatures for 2 years (January 2001–December 2002) which is the period when the most recent adults in the barnacle community would have settled and grown to adulthood. The proportion of the dry-loving barnacle Chthamalus montagui Southward increased within the barnacle guild at all scales as the habitat became warmer and drier. Barnacle densities were high in all habitats, mean densities ranged from a minimum of 4.16 cm⁻² on moderately exposed shores to a maximum of 6.27 cm⁻² in sunlit or south-facing microclimates. Percentage cover of barnacles across the gradient of latitudes was usually >70%. The results suggest that the distribution and abundance of interacting barnacle species on European coasts is strongly controlled by abiotic factors, most likely temperature and desiccation.     

Flight initiation distance decreases during social activity in lizards (<Emphasis Type="Italic">Sceloporus virgatus</Emphasis>)

Flight initiation distance, the predator–prey distance when escape begins, is predicted by escape theory to decrease if fleeing entails loss of benefits. Shortening of flight initiation distance during social interactions is known only in males and only in a few species. In a previous study, male, but not female, Sceloporus virgatus lizards had shorter flight initiation distance when interacting with tethered conspecifics. Females in that study were not gravid or close to ovulating. I predicted that flight initiation distance would be shorter in gravid females that perform sidle-hopping displays to reject courtship than in lone females. I tested this prediction and examined effects of social interactions by males with free-ranging conspecifics to ensure that previous findings were not artifacts of tethering and experimental introduction of conspecifics. Flight initiation distance was shorter in females when interacting with males than when alone; it was also shorter in males interacting with either sex. Thus, when beneficial for reproductive reasons, social interaction affects flight initiation distance in females, but at other times, it does not. Lesser shortening of flight initiation distance in females than males may be a consequence of greater social benefit to males and protection of reproductive investment by females.     

HISTORY of the Air Pollution Control Association

Bottom ash is a waste material from coal-fired power plants, and it is known to contain elements that are potentially toxic at high concentration levels when disposed in landfills. This study investigates the use of bottom ash as a partial substitute sorbent for wet flue gas desulfurization (FGD) processes by focusing on its leaching kinetics in adipic acid. This was studied basing on the shrinking core model that was applied to the experimental data obtained by the authors presented at the International Conference on Industrial, Manufacturing, Automation and Mechanical Engineering, Johannesburg, South Africa, November 27–28, 2013) on dissolution of bottom ash. The leaching rate constant was obtained from different reaction variables, namely, temperature, pH, acid concentration, and solid-to-liquid ratio, that could affect the leaching process. The solid sample of bottom ash was characterized at different leaching periods using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that solid-to-liquid ratio had a significant effect on the leaching rate constant when compared with other variables. The leaching kinetics showed that diffusion through the product layer was the rate-controlling step during leaching, and the activation energy for the process was found to be 18.92 kJ/mol.

Implications:?The use of coal bottom ash waste as a sorbent substitute in wet flue gas desulfurization (FGD) has both economic and environmental advantages. This is because it is a waste from coal-fired thermal power plant and this study has proven that it can leach out a substantial amount of calcium ions for wet FGD process. This will abate anthropogenic pollution due to landfill disposal of bottom ash wastes and also reduce sulfur dioxide emissions.     

Species-specific and context-dependant disruption of temporal population fluctuations resulting from hypereutrophication events

This study quantifies the disruption of zooplankton population fluctuations in relation to two magnitudes of fire retardant contamination events using artificial ponds as model systems. Population time series were analysed using redundancy analysis where time was modelled with a principal coordinate of neighborhood matrices approach that identified relevant scales of fluctuation frequencies. Analyses of temporal coherence provided insight whether population fluctuations correlated with system intrinsic or extrinsic forces. Responses to stress were species-specific and context-dependant. Contamination changed temporal structure in some species. These alterations were associated with an increased intrinsic control of dynamics. In some cases the magnitude of impact was unrelated to contamination severity. Some populations were less tolerant of pollution in the low relative to the high concentration treatment. Results suggest that population-level monitoring of degraded sites may be suboptimal because disparate population responses complicate the selection of specific sentinel organisms to monitor stress.