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271.
Restoration of a Canadian Prairie Wetland with Agricultural and Municipal Wastewater 总被引:1,自引:0,他引:1
3 /day (800,000 US gallons) of municipal wastewater and beef processing wastewater. A large nongovernmental organization hastened
restoration with a development process that outlined restoration goals and management objectives to satisfy a dual mandate
of wastewater treatment and wildlife habitat creation. In 1995, after five years of wastewater additions, the basins had been
refilled and the surrounding uplands had been acquired and restored. The Frank Lake Conservation Area currently provides high-quality
habitat for a variety of wildlife in a region where many of the native plants and animals species have been lost due to habitat
loss and fragmentation. The success of upland and water management strategies is reflected in the increase of target species'
abundance and richness: 50 shorebird species, 44 waterfowl species, 15 raptor species, and 28 other new bird species have
returned to the marsh since restoration. As well, significant N and P reduction occurs as waters flow through the first basin
of the marsh. The management strategies of this project that satisfied a dual mandate serve as a model to guide managers of
other large-scale wetland restoration projects. 相似文献
272.
Motivated by the problem of detecting spatial autocorrelation in increment- averaged data from soil core samples, we use the
Cholesky decomposition of the inverse of an autocovariance matrix to derive a parametric linear regression model for autocovariances.
In the absence of autocorrelation, the off-diagonal terms in the lower triangular matrix from the Cholesky decomposition should
be identically zero, and so the regression coefficients should be identically zero. The standard F-test of this hypothesis and two bootstrapped versions of the test are evaluated as autocorrelation diagnostics via simulation.
Size is assessed for a variety of heteroskedastic null hypotheses. Power is evaluated against autocorrelated alternatives,
including increment-averaged Ornstein-Uhlenbeck and Matérn processes. The bootstrapped tests maintain approximately the correct
size and have good power against moderately autocorrelated alternatives. The methods are applied to data from a study of carbon
sequestration in agricultural soils. 相似文献
273.
Kelly M. Proffitt Robert A. Garrott Jay J. Rotella 《Behavioral ecology and sociobiology》2008,62(10):1679-1687
The Trivers–Willard model predicts that in polygynous species, superior-quality females will maximize their fitness by producing
male offspring. Using a sample of 1,780 Weddell seal (Leptonychotes weddellii) pups recorded over 31 years, we investigated relationships between offspring sex ratio and maternal age, reproductive experience,
an index of maternal lifetime reproductive output, and annual environmental variations. We found evidence that females with
higher index of lifetime reproductive output were more likely to produce male than female offspring but found only weak evidence
that large-scale environmental variations influenced sex ratios. Our results suggest that mothers manipulate offspring sex
to maximize their own fitness, and inherent maternal quality may influence offspring sex. These findings support the Trivers–Willard
sex-allocation model.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
274.
Species-specific variation in cuttlebone δ13C and δ18O for three species of Mediterranean cuttlefish
Michael A. Dance Giambattista Bello Nathan B. Furey Jay R. Rooker 《Marine Biology》2014,161(2):489-494
Stable carbon (δ13C) and oxygen (δ18O) isotopes in cuttlebones of three species of Mediterranean cuttlefish (Sepia elegans, S. officinalis, and S. orbignyana) with different life histories were contrasted. Cuttlebone δ13C and δ18O were quantified at both the core and edge (representing early life and recent deposition, respectively) for all three species sampled from the southern Adriatic Sea in 2010 (n = 28). For S. officinalis, cuttlebone δ13C and δ18O values were both lower relative to S. elegans and S. orbignyana at the core by approximately 1.0–2.0 and 3.0 ‰, respectively. Differences between core and edge in cuttlebone δ13C and δ18O were also observed for S. officinalis with observed values at the cuttlebone edge (recent) exceeding core (early life) values by 2.5 ‰ for δ13C and 1.4 ‰ for δ18O. Differences in isotopic composition across S. officinalis cuttlebones are possibly reflective of ontogenetic migrations from nearshore nurseries (lower seawater δ13C and δ18O values) to offshore overwintering habitats (higher seawater δ13C and δ18O values). Overall, results from this study suggest that cuttlebone δ13C and δ18O hold promise as natural tags for determining the degree of spatial connectivity between nearshore and offshore environments used by cuttlefish. 相似文献
275.
Atmospheric Change and Biodiversity in the Arctic 总被引:2,自引:0,他引:2
Roger I. C. Hansell Jay R. Malcolm Harold Welch Robert L. Jefferies Peter A. Scott 《Environmental monitoring and assessment》1998,49(2-3):303-325
The Canadian Arctic is characterized by a high variation in landform types and there are complex interactions between land, water and the atmosphere which dramatically affect the distribution of biota. Biodiversity depends upon the intensity, predictability and scale of these interactions. Observations, as well as predictions of large-scale climate models which include ocean circulation, reveal an anomalous cooling of northeastern Canada in recent decades, in contrast to the overall significant increase in average annual temperature in the Northern Hemisphere. Predictions from models are necessary to forecast the change in the treeline in the 21st century which may lead to a major loss of tundra. The rate of change in vegetation in response to climate change is poorly understood. The treeline in central Canada, for example, is showing infilling with trees, and in some locations, northerly movement of the boundary. The presence of sea ice in Hudson Bay and other coastal areas is a major factor affecting interactions between the marine and terrestrial ecosystems. Loss of ice and therefore hunting of seals by polar bears will reduce bear and arctic fox populations within the region. In turn, this is likely to have significant effects on their herbivorous prey populations and forage plants. Further, the undersurface of sea ice is a major site for the growth of algae and marine invertebrates which in turn act as food for the marine food web. A rise in sea-level may flood coastal saltmarsh communities leading to changes in plant assemblages and a decline in foraging by geese and other consumers. The anomalous cooling in the eastern Arctic, primarily in late winter and early spring, has interrupted northern migration of breeding populations of geese and ducks and led to increased damage to vegetation in southern arctic saltmarshes as a result of foraging. It is likely that there has been a significant loss of invertebrates in those areas where the vegetation has been destroyed. Warming will have major effects on permafrost distribution and on ground-ice resulting in a major destabilization of slopes and slumping of soil, and disruption of tundra plant communities. Disruption of peat and moss surfaces lead to loss of insulation, an increase in active-layer depth and changes in drainage and plant assemblages. Increases of UV-B radiation will strongly affect vulnerable populations of both plants and animals. The indigenous peoples will face major changes in life style, edibility of food and health standards, if there is a significant warming trend. The great need is for information which is sensitive to the changes and will assist in developing an understanding of the complex interactions of the arctic biota, human populations and the physical environment. 相似文献
276.
Morgan JA Hoet AE Wittum TE Monahan CM Martin JF 《Journal of environmental quality》2008,37(1):272-279
Ecological treatment systems can provide a sustainable, plant-based alternative to traditional wastewater treatment. One factor essential to the success of these systems is ensuring their ability to reduce coliform concentrations in wastewater. Wastewater is the primary source of fecal contamination in aquatic ecosystems, containing total and fecal coliforms on the order of 10(8)-10(10) and 10(7)-10(9) CFU L(-1), respectively. This study assessed the ability of an ecological treatment system to reduce concentrations of total coliforms and Escherichia coli from dairy wastewater. Low strength wastewater was pumped into the system during July of 2005 and high strength in September 2005. Wastewater passes through a series of anaerobic, aerobic, and clarifier reactors and wetland cells before exiting the system. Regardless of wastewater strength, average total coliform and E. coli concentrations were consistently reduced by at least 99% from influent to effluent, with the majority of the reduction (76%) occurring in the first two reactors. Relationships between internal concentrations of solids and coliforms indicated that increased reduction of solids may further reduce coliform concentrations. Although U.S. Environmental Protection Agency discharge requirements for E. coli were not always met, the substantial reductions achieved indicate that ecological treatment systems have the potential to successfully reduce coliforms in wastewater to meet discharge limits. The results from this study will be used to guide design and management of future ecological treatment systems, so that larger and more consistent coliform reductions can be achieved. 相似文献
277.
David C. Snyder James J. Schauer Deborah S. Gross Jay R. Turner 《Atmospheric environment (Oxford, England : 1994)》2009,43(26):4033-4042
Single-particle mass spectra were collected using an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) during December of 2003 and February of 2004 at an industrially impacted location in East St. Louis, IL. Hourly integrated peak areas for twenty ions were evaluated for their suitability in representing metals/metalloids, particularly those reported in the US EPA Toxic Release Inventory (TRI). Of the initial twenty ions examined, six (Al, As, Cu, Hg, Ti, and V) were found to be unsuitable due to strong isobaric interferences with commonly observed organic fragments, and one (Be) was found to have no significant signal. The usability of three ions (Co, Cr, and Mn) was limited due to suspected isobaric interferences based on temporal comparisons with commonly observed organic fragments. The identity of the remaining ions (Sb, Ba, Cd, Ca, Fe, Ni, Pb, K, Se, and Zn) was substantiated by comparing their signals with the integrated hourly signals of one or more isotope ions. When compared with one-in-six day integrated elemental data as determined by X-ray fluorescence spectroscopy (XRF), the daily integrated ATOFMS signal for several metal ions revealed a semi-quantitative relationship between ATOFMS peak area and XRF concentrations, although in some cases comparison of these measurements were poor at low elemental concentrations/ion signals due to isobaric interferences. A method of estimating the impact of local point sources was developed using hourly integrated ATOFMS peak areas, and this method attributed as much as 85% of the concentration of individual metals observed at the study site to local point sources. Hourly surface wind data were used in conjunction with TRI facility emissions data to reveal likely point sources impacting metal concentrations at the study site and to illustrate the utility of using single-particle mass spectral data to characterize atmospheric metals and identify point sources. 相似文献
278.
279.
Exhausted carbon coming from the H2S adsorption process is a big environmental problem in Wastewater Treatment Plants. In this study, reusing exhausted carbon as a carrier of sulfide-oxidizing bacteria in lab-scale biofilters was evaluated. The exhausted carbons from different heights of the adsorption bed have different exhaustion extents, i.e. characteristics in terms of sulfur content, pH and porosity. Therefore, four biofilters were packed separately with exhausted carbon from top, middle, bottom of H2S adsorption bed, and a mixture of the three, to investigate the suitability for further H2S biofiltration. The results showed a quick startup in these biofilters (approximately 80 h). The numbers of sulfide-oxidizing bacteria immobilized on activated carbon were approximately 4.8, 9.2 and 14 x 108 CFU g-1 top, middle and bottom carbon after the 240-h operation, respectively. In addition, the biofilters demonstrated a rapid recovery to the original removal efficiency (RE) within 2 h after the H2S spike loadings. After a 110-h shutdown, the RE was rapidly recovered for all the biofilters within 5 h, with a shorter time (1 h) observed for the bottom carbon biofilter. The H2S removal mechanism of these biofilters was studied through a full analysis of sulfur products in both liquid (recycling medium) and activated carbon, and variable characterization of activated carbon before and after biofiltration. This study shows that the exhausted carbon-based biofilter is a feasible and economical alternative to conventional odor biofiltration. 相似文献
280.
Role of protein, amino acids, and enzyme activity on odor production from anaerobically digested and dewatered biosolids. 总被引:2,自引:0,他引:2
Matthew J Higgins Gregory Adams Yen-Chih Chen Zeynep Erdal Robert H Forbes Dietmar Glindemann J Ronald Hargreaves David McEwen Sudhir N Murthy John T Novak Jay Witherspoon 《Water environment research》2008,80(2):127-135
The main objective of this research was to test the hypothesis that bioavailable protein and, more specifically, the sulfur-containing amino acids within the protein, can be degraded by proteolytic enzymes to produce odor-causing compounds--mainly volatile sulfur compounds (VSCs)--during biosolids storage. To achieve these objectives, samples of digester effluent and cake solids were collected at 11 different wastewater treatment plants in North America, and the samples were analyzed for protein and amino acid content and general protein-degrading enzyme activity. At the same time, cake samples were stored using headspace bottles, the concentration of VSCs were measured using gas chromatography, and olfactometry measurements were made by a trained odor panel. The results showed that the bound cake protein content and methionine content was well-correlated with VSC production and the detection threshold measured by the odor panel. 相似文献