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D. Martin Fleming Wilfried F. Wolff Donald L. DeAngelis 《Environmental management》1994,18(5):743-757
Declines in populations of and reproductive success of wood storks and other wading birds have occurred in the Florida Everglades
over the past several decades. These declines have been concurrent with major changes in the Everglades’ landscape characteristics.
Among the plausible hypotheses that relate to landscape change are the following: (1) general loss of habitat; (2) heavy loss
of specific habitat, namely, short-hydroperiod wetlands that provide high prey availability early in the breeding season;
and (3) an increase in frequency of major drying out of the central slough areas, which can affect prey availability late
in the breeding season.
These three hypotheses were compared using an individual-based model of wood stork (Mycteria americana) reproduction. This model simulated the behavior and energetics of each individual wood stork in a breeding colony on 15-min
time intervals. Changes in water depth and prey availability occurred on daily time steps. Simulation results showed a threshold
response in reproductive success to reduction of wetland heterogeneity. Model comparisons in which (1) only short-hydroperiod
wetlands were removed and (2) wetlands of both long and short hydroperiods were removed showed that, for the same loss of
total area, the specific habitat removal caused a much greater reduction in wood stork reproduction, indicating hypothesis
2 may be a more likely explanation than hypothesis 1. Reduction of initial prey availability in the central slough areas (simulating
frequent drying; hypothesis 3) reduced fledging success by an average of more than 90% in the model. 相似文献
995.
The photooxidation of a nonwoven polyethylene fabric was investigated using Fourier transform infrared photoacoustic spectroscopy. The infrared spectroscopic data indicated that hydroperoxide, alcohol, aldehyde, ketone, carboxylic acid, and anhydride groups were formed as the products of the photooxidation of the polyethylene fabric and that the relative amount of carboxyl among all carbonyls increased as the photooxidation progressed. The distribution of the photooxidation products was inhomogeneous between the two surfaces of the fabric. The highest degree of photooxidation occurred on the surface of the fabric facing the UV radiation source, whereas the lowest degree of photooxidation was on the back surface of the fabric. We also found that the polyethylene nonwoven fabric showed a slower photooxidation rate than the polypropylene nonwoven fabric. The UV radiation at 254 nm caused photooxidation of polyethylene. No photooxidation was observed in the fabric exposed to the UV radiation at 350 nm under the same conditions. 相似文献
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Martin B. Hocking 《Environmental management》1986,10(2):179-187
Here are assembled representative excerpts from a new text in applied chemistry. They illustrate the well-referenced treatment of industrial processes that are here considered with their related emission control problems and solutions. A brief account of general aspects of the industry is followed by surveys of the significance and technical aspects of air and water pollution chemistry. Consideration is given to emission avoidance or containment, waste treatment, and waste disposal options as they relate to both of these environmental areas. Details of salt recovery and the products of brine electrolysis plus environmental aspects of these operations are treated as examples of some of the processes discussed. Also covered are fertilizer constituent preparation, formulation, and use with consideration of the large-scale effects of each of these activities. Detailed reference is made to the chemical technology and emission control aspects of the pulp and paper industry and refinery operations. Throughout, integral process changes and waste recycling practices are directly related to emission control aspects of each process in a way to be useful to the student and professional alike. These excerpts are extracted from one of the first, single volume accounts to take this unified approach to the subject.Extract from the bookModern Chemical Technology and Emission Control by M. B. Hocking, published by Springer-Verlag, Berlin, Heidelberg, New York, Tokyo (1985). 相似文献
999.
The article presents a holistic approach to studying and applying crop protection in agricultural systems A theoretical framework of integrated pest management (IPM) is presented that allows an understanding of pest population processes on a whole-agroecological-system basis The need for and emergence of holistic research on agroecosystems is discussed, as are the current trends in ecological theory and pest management 相似文献
1000.
Allan G. Sangster Lewis Ling Frédéric Gérard Martin J. Hodson 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):143-149
Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] shoots from mature trees were collected from two sites of contrasting soil pH: the Glendon campus of York
University in Toronto, Canada (pH 6.7 at 40 cm) designated Can.; and Breuil Forest, Morvan, France (pH 4 to 4.5) designated
Fr.. Needles were removed from the shoots, frozen in liquid nitrogen, and kept in a cryo-biological storage system prior to
X-ray microanalysis on the cold stage (−170°C) of a cryo-SEM. Four elements detected, potassium, phosphorus, sulphur and chlorine,
were ubiquitous in the needle tissues from both sites. Manganese was infrequently found in needle tissues from the Fr. site.
Calcium was localized most heavily in the outer tangential wall of the hypodermis and also in the epidermal walls. Silicon
(Si) concentrations were higher in the Fr. site than in the Can. site. The epidermis, hypodermis and mesophyll of needles
from the Fr. site exhibited the highest Si content, with greater amounts in the tip and middle of the needle than in the base.
Aluminium was distributed fairly evenly throughout the tissues, and there were few major sites of concentration. 相似文献