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51.
This study describes the results of a survey of 432 homeowners in Ohio, USA concerning their perceptions and practices regarding management of residential landscapes. The results reveal that outdoor residential environments are extremely important to homeowners, who tend to view their yards as serving multiple functions: a place to observe nature and to socialize as well as a place of beauty and recreation. Use of a lawn care company to apply chemicals is reported by 22 % of respondents, while 40 % either apply chemicals themselves or have someone other than a lawn care company do it. Logistic regressions reveal that factors influencing a homeowner's decision to employ a lawn care company or to apply chemicals themselves include: household income (+), perceived impacts on the environment (-), whether the next door neighbor does it (+), and type of residential environment (rural -, suburban and urban +). A theme that emerges throughout the study is the perceived importance of the role of the lawn in residents' sense of social status or acceptance in the neighborhood. This perception can be viewed as a positive in ensuring that residential environments are well maintained, but also as a negative resulting in environmental degradation or presenting a barrier to creativity in the development of alternative residential environments. Specific policy implications of these findings are that efforts aimed at educating homeowners about the environmental impacts of their lawn care choices are likely to have more success if they are directed at neighborhood groups rather than individuals, show that alternatives are easy to adopt, affordable, and can produce the characteristics of lawns that homeowners seek. 相似文献
52.
Stream pollution from animal production units 总被引:1,自引:0,他引:1
53.
Rochelle Constantine Debbie Steel Judy Allen Megan Anderson Olive Andrews C. Scott Baker Peta Beeman Daniel Burns Jean-Benoît Charrassin Simon Childerhouse Michael Double Paul Ensor Trish Franklin Wally Franklin Nick Gales Claire Garrigue Nadine Gibbs Peter Harrison Nan Hauser Amanda Hutsel Curt Jenner Micheline-Nicole Jenner Greg Kaufman Anne Macie David Mattila Carlos Olavarría Adrian Oosterman David Paton Michael Poole Jooke Robbins Natalie Schmitt Peter Stevick Alden Tagarino Kirsten Thompson Juney Ward 《Marine Biology》2014,161(5):1087-1093
Understanding the dynamics of population recovery is particularly complex when an organism has multiple, remote breeding and feeding grounds separated by one of the longest known migration routes. This study reports on the most comprehensive assessment of humpback whale (Megaptera novaeangliae) movements between remote Antarctic waters south of New Zealand and east Australia (EA), and the migratory corridors and breeding grounds of Australia and Oceania. A total of 112 individual whales were identified; 57 from microsatellites and 61 by fluke with 23 % (n = 26) matched to sites outside Antarctica. Despite large datasets from other southern regions being included in the comparison, the whales were predominantly linked to EA (n = 24). Only two matches to the Oceania catalogues directly north was surprising; therefore the primary feeding grounds of these endangered whales still remain unknown. The confirmation of the Balleny Islands as an important feeding ground for EA whales could provide an insight into reasons behind the rapid recovery of this population. Determining the feeding grounds of Oceania’s whales may explain whether prey energetics or migration length are limiting factors to their recovery and will allow an understanding of future ecosystem changes in these whales. 相似文献
54.
Thomas Breuer Andrew M. Robbins Claudia Olejniczak Richard J. Parnell Emma J. Stokes Martha M. Robbins 《Behavioral ecology and sociobiology》2010,64(4):515-528
Variance in male reproductive success is expected to be high in sexually dimorphic mammals, even when it is modulated by the
costs and benefits of group living. Here, we investigate the variance in reproductive success of male western gorillas (Gorilla gorilla), a highly dimorphic primate with long-term male–female associations, using 12.5 years of data collected at Mbeli Bai in
northern Congo. Access to mates and offspring survival were both major sources of variance in male reproductive success. Males
with larger harems had lower offspring mortality with no apparent reduction in female fertility or observed tenure length,
so the size of harems did not seem to be limited by female feeding competition or by the risk of takeovers and infanticide
by outsider males. The lower mortality in larger harems may reflect improved vigilance against predators, and females may
cluster around males that enhance offspring survival. Thus, this study illustrates how a detailed analysis of the components
of male reproductive success can shed light on the interrelated social and ecological aspects that affect it. 相似文献
55.
Barry P Rochelle Donald L. Stevens M. Robbins. Church 《Journal of the American Water Resources Association》1989,25(3):491-498
ABSTRACT: The U.S. Environmental Protection Agency (EPA) in cooperation with the U.S. Geological Survey (USGS) conducted an analysis to quantify the uncertainty associated with interpolating runoff to specific sites using a runoff contour map. We interpolated runoff to 93 gaged watersheds from a runoff contour map using (1) hand interpolation to the watershed outlet, (2) a computer interpolation to the watershed outlet, and (3) hand interpolation to the watershed centroid. We compared the interpolated values to the actual gaged values and found that there was a bias in the average interpolated value for runoff estimated at basin outlets, with interpolated values being less than the actual. We found no significant difference between the hand interpolation method and the computer interpolation method except that the computer method tended to have higher variability due to factors inherent to the software used. There were no strong spatial correlations or regional patterns in the runoff interpolations, which indicates that there are no regional biases introduced in the development of the contour map. We determined that we could estimate runoff, on the average, within approximately 8.9 cm (3.5 in; 15 percent) of the measured value using the three methods. The results of this work indicate that runoff contour maps can he used in regional studies to estimate runoff to ungaged systems with quantifiable uncertainty. 相似文献
56.
Xiaoliang Wang Curtis Robbins S. Kent Hoekman Judith C. Chow John G. Watson Dennis Schuetzle 《Frontiers of Environmental Science & Engineering in China》2011,5(3):320-330
Thermochemical biomass gasification, followed by conversion of the produced syngas to fuels and electrical power, is a promising
energy alternative. Real-world characterization of particulate matter (PM) and other contaminants in the syngas is important
to minimize damage and ensure efficient operation of the engines it powers and the fuels created from it. A dilution sampling
system is demonstrated to quantify PM in syngas generated from two gasification plants utilizing different biomass feedstocks:
a BioMax?15 Biopower System that uses raw and torrefied woodchips as feedstocks, and an integrated biorefinery (IBR) that
uses rice hulls and woodchips as feedstocks. PM2.5 mass concentrations in syngas from the IBR downstream of the purification system were 12.8–13.7 μg·m−3, which were significantly lower than the maximum level for catalyst protection (500 μg·m−3) and were 2–3 orders of magnitude lower than those in BioMax?15 syngas (2247–4835 μg·m−3). Ultrafine particle number concentration and PM2.5 chemical constituents were also much lower in the IBR syngas than in the BioMax?15. The dilution sampling system enabled
reliable measurements over a wide range of concentrations: the use of high sensitivity instruments allowed measurement at
very low concentrations (∼1 μg·m−3), while the flexibility of dilution minimized sampling problems that are commonly encountered due to high levels of tars
in raw syngas (∼1 g·m−3). 相似文献
57.