Characterization of gaseous pollutant and particulate matter emission rates from a commercial broiler operation part I: Observed trends in emissions

This paper characterizes the emission rates of size fractionated particulate matter, inorganic aerosols, acid gases, ammonia and methane measured over four flocks at a commercial broiler chicken facility. Mean emission rates of each pollutant, along with sampling notes, were reported in this paper, the first in a series of two. Sampling notes were needed because inherent gaps in data may bias the mean emission rates.The mean emission rates of PM₁₀ and PM_2.5 were 5.0 and 0.78 g day^?1 [Animal Unit, AU]^?1, respectively, while inorganic aerosols mean emission rates ranged from 0.15 to 0.46 g day^?1 AU^?1 depending on the season. The average total acid gas emission rate was 0.43 g day^?1 AU^?1 with the greatest contribution from nitrous and nitric acids and little contribution from sulfuric acid (as SO₂).Ammonia emissions were seasonally dependent, with a mean emission rate of 66.0 g day^?1 AU^?1 in the cooler seasons and 94.5 g day^?1 AU^?1 during the warmer seasons. Methane emissions were relatively consistent with a mean emission rate of 208 g day^?1 AU^?1.The diurnal pattern in each pollutant’s emission rate was relatively consistent after normalizing the hourly emissions according to each daily mean emission rate. Over the duration of a production cycle, all the measured pollutants’ emissions increased proportionally to the total live mass of birds in the house, with the exception of ammonia.Interrelationships between pollutants provide evidence of mutually dependent release mechanisms, which suggests that it may be possible to fill data gaps with minimal data requirements. In the second paper (Roumeliotis, T.S., Dixon, B.J., Van Heyst, B.J. Characterization of gaseous pollutants and particulate matter emission rates from a commercial broiler operation part II: correlated emission rates. Atmospheric Environment, 2010.), regression correlations are developed to estimate daily mean emission rates for data gaps and, using the normalized hourly diurnal patterns from this paper, emission factors were generated for each pollutant.     

Role of back diffusion and biodegradation reactions in sustaining an MTBE/TBA plume in alluvial media

A methyl tert-butyl ether (MTBE) / tert-butyl alcohol (TBA) plume originating from a gasoline spill in late 1994 at Vandenberg Air Force Base (VAFB) persisted for over 15 years within 200 feet of the original spill source. The plume persisted until 2010 despite excavation of the tanks and piping within months after the spill and excavations of additional contaminated sediments from the source area in 2007 and 2008. The probable history of MTBE concentrations along the plume centerline at its source was estimated using a wide variety of available information, including published details about the original spill, excavations and monitoring by VAFB consultants, and our own research data. Two-dimensional reactive transport simulations of MTBE along the plume centerline were conducted for a 20-year period following the spill. These analyses suggest that MTBE diffused from the thin anaerobic aquifer into the adjacent anaerobic silts and transformed to TBA in both aquifer and silt layers. The model reproduces the observation that after 2004 TBA was the dominant solute, diffusing back out of the silts into the aquifer and sustaining plume concentrations much longer than would have been the case in the absence of such diffusive exchange. Simulations also suggest that aerobic degradation of MTBE or TBA at the water table in the overlying silt layer significantly affected concentrations of MTBE and TBA by limiting the chemical mass available for back diffusion to the aquifer.     

Spatio-temporal distribution of organic and inorganic pollutants from Lake Geneva (Switzerland) reveals strong interacting effects of sewage treatment plant and eutrophication on microbial abundance

Variation with depth and time of organic matter (carbon, nitrogen, phosphorus), inorganic pollutant (mercury), as well as bacterial abundance and activity, were investigated for the first time in sediment profiles of different parts of Lake Geneva (Switzerland) over the last decades. The highest organic contents (about 32%), mercury concentration (27 mg kg⁻¹), bacterial abundance (in order of 9 × 10⁹ cell g⁻¹ dry sediment), and bacterial activity (1299 Relative Light Units (RLU)) were found in the highly polluted sediments contaminated by the waste water treatment plant (WWTP) discharge, which deposited during the period of cultural eutrophication. Such data, which contrast with the other sampled sites from deeper and more remote parts of the lake, prove that the organic matter and nutrients released from the municipal WWTP have considerable effects on bacterial abundance and activities in freshwater sediments. In fact, the relatively unpolluted deepwater sites and the coastal polluted site show large synchronous increases in bacterial densities linked to the anoxic conditions in the 1970s (lake eutrophication caused by external nutrient input) that subsequently increased the nutrient loading fluxes. These results show that the microbial activities response to natural or human-induced changing limnological conditions (e.g., nutrient supply, oxygen availability, redox conditions) constitutes a threat to the security of water resources, which in turn poses concerns for the world’s freshwater resources in the context of global warming and the degradation of water quality (oxygen depletion in the bottom water due to reduced deep waters mixing). Moreover, the accumulation of inorganic pollutants such as high mercury (methyl-mercury) concentration may represent a significant source of toxicity for sediment dwelling organisms.     

Roles of environmental movement organisations in land-use planning: case studies of the Niagara Escarpment and Oak Ridges Moraine,Ontario, Canada

The paper explores the roles of environmental movement organisations (EMOs) in land-use planning, including domain creation (establishment of new or modified landscape planning boundaries) and regime change (adoption of new or modified legal and planning rules). The research involved two case studies of land-use planning processes: the Niagara Escarpment and Oak Ridges Moraine, Ontario, Canada. The two cases together reveal an evolution of land-use planning towards collaborative processes on mainly private lands in Southern Ontario during the period from 1960 to 2002. The results suggest that EMOs can create new planning domains through agenda setting activities, build landscape value and vision, educate governments and the public, and work to maintain and alter regimes. Collaborative planning has emerged as an important process in which some EMOs are now participating.     

Evaluation of the Chemcatcher and DGT passive samplers for monitoring metals with highly fluctuating water concentrations

Passive sampling devices accumulate chemicals continuously from water and can provide time weighted average (TWA) concentrations of pollutants over the exposure period. Hence, they offer a number of advantages over other conventional monitoring techniques such as spot or grab sampling. The diffusive gradient in thin film (DGT) and the Chemcatcher passive samplers can be used to provide TWA concentrations of labile metals, but the approaches to their calibration differ. DGT uses diffusion coefficients of metals in the hydrogel layer, whereas Chemcatcher uses metal specific uptake rates, with both sets of values obtained under controlled laboratory conditions with constant aqueous metal concentrations. However, little is known of how such samplers respond to fluctuating concentrations. We evaluated the responsiveness of these two passive sampling devices to rapidly changing concentrations of Cd, Cu, Ni, Pb and Zn in natural freshwater, over a relatively short deployment time. Maximum metal concentrations in water were varied between 70 and 140 microg L(-1). Experiments were carried out in a tank with a rotating carousel system and filled with Meuse river water, allowing a degree of control over experimental conditions while using natural river water. Fluctuating concentrations were obtained by stepwise addition of standard solutions of the metals. The reliability and accuracy of the TWA concentrations measured by the samplers were assessed by comparison with concentrations of the metals in spot samples of water taken regularly over the deployment period. The spot samples of water were either unfiltered (total), filtered (0.45 microm) or ultrafiltered (5 kDa). Predictive speciation modelling using the visual MINTEQ programme was also undertaken. There was reasonable agreement between the TWA concentrations of Cd and Ni obtained with Chemcatcher and DGT and the total Cd and Ni concentrations measured in repeated unfiltered spot samples. For elements (i.e. Cu, Pb, Zn) that associate to a significant degree with suspended solids, colloids or dissolved organic carbon, or form complexes with large organic ligands, optimum agreement was with the filtered or ultrafiltered fractions and with the predicted inorganic and inorganic-fulvic acid associated fractions. While Chemcatcher-based TWA concentration ranges for Cu and Zn were in best agreement with the total filtered fraction, there was lack of agreement for Pb. The combined use of DGT devices with open pore (OP) and restricted pore (RP) gels allowed the labile fraction of metal associated with large organic ligands or DOC to be differentiated and quantified, since this is available to DGT OP but unable to diffuse into the DGT RP. This evaluation of the two sampling devices clearly demonstrated their ability to react reliably to transient peaks in concentration of metal pollutants in water and indicated where future efforts are needed to improve calibration data. Such samplers may prove valuable in responding to the monitoring requirements of the European Union's Water Framework Directive.     

Application of Genetic Bottleneck Testing to the Investigation of Amphibian Declines: a Case Study with Natterjack Toads

Abstract: Declines of amphibians are causing widespread concern and in some cases have been explained by factors such as climate change and the spread of microbial pathogens. A problem remains, however, in the unequivocal demonstration of decline in situations where populations may be undergoing natural fluctuations in abundance. We describe the application of a genetic test for bottlenecks ( Cornuet & Luikart 1996 ) that should distinguish between natural oscillations and true population declines. British natterjack toads (   Bufo calamita  ) provide examples of populations that have not declined in recent decades, populations that have declined, and populations in which trends are unclear. Microsatellite allele frequency data from these populations were tested for heterozygote excess and shifts in allele frequency distributions, and inferences from these computations about bottlenecks (i.e., persistently smaller population sizes than the recent means) were compared with demographic information. The genetic test correctly identified bottlenecks and should therefore prove useful in demonstrating whether amphibian declines have occurred where long-term demographic time series are not available.     

Factors Influencing Movement Patterns of Keel-Billed Toucans in a Fragmented Tropical Landscape in Southern Mexico

Abstract: Various factors influence animal movements in fragmented landscapes, and determining these factors is key to understanding ecological processes at a landscape scale. My goals were (1) to determine what factors influence movements of Keel-billed Toucans (    Ramphastos sulfuratus ) in a fragmented landscape in southern Mexico and (2) to use this information to predict how movement patterns might change if the landscape was altered. I developed a cost-distance geographic information system model that adjusts Euclidean distances by a cost of moving through a certain habitat type. Cost was based on habitat preferences exhibited by toucans. I then used this model to predict how movements might be affected by removal of isolated trees and living fences from the pasture matrix and by removal of forest remnants. Toucans moved more frequently between remnants separated by a low cost-distance value. There was a cost-distance threshold beyond which movements between remnants were rare. Below this threshold, fruit abundance influenced toucan movements but remnant area was not influential in that toucans did not preferentially move to large patches. Remnants close to various other remnants were more frequently visited by toucans, indicating that landscape connectivity influences toucan movements. Toucans incurred a 10–30% cost increase when moving in computer-simulated landscapes, indicating that changes in forest cover or configuration of habitats may negatively affect toucan populations, assuming that increased cost has a fitness consequence. Cost-distance modeling has been relatively unexplored and may be a valuable tool for determining how the configuration of a landscape impedes or facilitates animal movements.     

Opportunities for better use of collective action theory in research and governance for invasive species management

Controlling invasive species presents a public-good dilemma. Although environmental, social, and economic benefits of control accrue to society, costs are borne by only a few individuals and organizations. For decades, policy makers have used incentives and sanctions to encourage or coerce individual actors to contribute to the public good, with limited success. Diverse, subnational efforts to collectively manage invasive plants, insects, and animals provide effective alternatives to traditional command-and-control approaches. Despite this work, there has been little systematic evaluation of collective efforts to determine whether there are consistent principles underpinning success. We reviewed 32 studies to identify the extent to which collective-action theories from related agricultural and environmental fields explain collaborative invasive species management approaches; describe and differentiate emergent invasive species collective-action efforts; and provide guidance on how to enable more collaborative approaches to invasive species management. We identified 4 types of collective action aimed at invasive species—externally led, community led, comanaged, and organizational coalitions—that provide blueprints for future invasive species management. Existing collective-action theories could explain the importance attributed to developing shared knowledge of the social-ecological system and the need for social capital. Yet, collection action on invasive species requires different types of monitoring, sanctions, and boundary definitions. We argue that future government policies can benefit from establishing flexible boundaries that encourage social learning and enable colocated individuals and organizations to identify common goals, pool resources, and coordinate efforts.     

Assessment of Alternative Methods for Statistically Downscaling Daily GCM Precipitation Outputs to Simulate Regional Streamflow

This study applied three statistical downscaling methods: (1) bias correction and spatial disaggregation at daily time scale (BCSD_daily); (2) a modified version of BCSD which reverses the order of spatial disaggregation and bias correction (SDBC), and (3) the bias correction and stochastic analog method (BCSA) to downscale general circulation model daily precipitation outputs to the subbasin scale for west‐central Florida. Each downscaled climate input dataset was then used in an integrated hydrologic model to examine differences in ability to simulate retrospective streamflow characteristics. Results showed the BCSD_daily method consistently underestimated mean streamflow because the highly spatially correlated small precipitation events produced by this method resulted in overestimation of evapotranspiration. Highly spatially correlated large precipitation events produced by the SDBC method resulted in overestimation of the standard deviation of wet season daily streamflow and the magnitude/frequency of high streamflow events. BCSA showed better performance than the other methods in reproducing spatiotemporal statistics of daily precipitation and streamflow. This study demonstrated differences in statistical downscaling techniques propagate into significant differences in streamflow predictions, and underscores the need to carefully select a downscaling method that reproduces precipitation characteristics important for the hydrologic system under consideration.