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991.
Historical aerial photographs (from 1946 through 1983) were used to study and describe the nature and extent of changes in wetland vegetation of a section of the St. Lawrence River and to evaluate the relative importance of water level, fire, and vegetational development as causal factors of these historical changes. Data were encoded and analyzed using a geographical information system, autocorrelation, and Mantel tests. Results show three temporal patterns in wetland dynamics. First, some wetland zones have been reduced by human activities (urbanization, landfilling, canal dredging). The second group consists of wetland areas that remain stable and do not change over time. They are generally protected sites artificially maintained by water-level control. A third situation has occurred in the Lake Saint-François National Wildlife Area, where no significant wetland losses were detected, but where landscape structure has changed greatly. Modeling with Mantel tests suggests that, in the latter case, these changes in wetland landscape are related to the suppression of burning (fires set deliberately by Indians) since the purchase of the territory by the Canadian federal government. This situation has caused rapid replacement of wet meadows byAlnus rugosa scrub and a possible decline in habitat diversity. 相似文献
992.
Trends and patterns in section 404 permitting requiring compensatory mitigation in Oregon and Washington,USA 总被引:1,自引:4,他引:1
Mary E. Kentula Jean C. Sifneos James W. Good Michael Rylko Kathy Kunz 《Environmental management》1992,16(1):109-119
The effects of permitting decisions made under Section 404 of the Clean Water Act for which compensatory mitigation was required
were examined. Information was compiled on permits issued in Oregon (January 1977–January 1987) and Washington (1980–1986).
Data on the type of project permitted, wetland impacted, and mitigation project were collected and analyzed. The records of
the Portland and Seattle District Offices of the US Army Corps of Engineers and of Environmental Protection Agency Region
X were the primary sources of information.
The 58 permits issued during the years of concern in Oregon document impacts to 82 wetlands and the creation of 80. The total
area of wetland impacted was 74 ha while 42 ha were created, resulting in a net loss of 32 ha or 43%. The 35 permits issued
in Washington document impacts to 72 wetlands and the creation of 52. The total area of wetland impacted was 61 ha while 45
ha were created, resulting in a net loss of 16 ha or 26%. In both states, the number of permits requiring compensation increased
with time. The area of the impacted and created wetlands tended to be ≤0.40 ha. Permitted activity occurred primarily west
of the Cascade Mountains and in the vicinity of urban centers. Estuarine and palustrine wetlands were impacted and created
most frequently. The wetland types created most often were not always the same as those impacted; therefore, local gains and
losses of certain types occurred. In both states the greatest net loss in area was in freshwater marshes.
This study illustrates how Section 404 permit data might be used in managing a regional wetland resource. However, because
the data readily available were either incomplete or of poor quality, the process of gathering information was very labor
intensive. Since similar analyses would be useful to resource managers and scientists from other areas, development of an
up-to-date standardized data base is recommended. 相似文献
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Francesca Romana Grati Denise Molina Gomes Jose Carlos Pinto B. Ferreira Celine Dupont Viola Alesi Laetitia Gouas Nina Horelli-Kuitunen Kwong Wai Choy Sandra García-Herrero Alberto Gonzalez de la Vega Krzysztof Piotrowski Rita Genesio Gloria Queipo Barbara Malvestiti Bérénice Hervé Brigitte Benzacken Antonio Novelli Philippe Vago Kirsi Piippo Tak Yeung Leung Federico Maggi Thibault Quibel Anne Claude Tabet Giuseppe Simoni François Vialard 《黑龙江环境通报》2015,35(8):801-809
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Bart De Keersmaecker Hilde Van Esch Dominique Van Schoubroeck Filip Claus Philippe Moerman Luc De Catte 《黑龙江环境通报》2013,33(3):292-295
We report the prenatal sonographic detection of a fetus with megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly. Only 14 patients have been reported in the literature so far, all but one were diagnosed postnatally. The polymicrogyria in the frontoparietal lobe was confirmed by prenatal magnetic resonance imaging. Additionally, a hypoplastic thymus as seen in a 22q11 deletion was present. Although polymicrogyria along with pre-axial polydactyly has been described in 22q11 deletion, the diagnosis of Di George syndrome was ruled out. The etiology of megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly has not been revealed yet. A dominant as well as recessive inheritance has been suggested. © 2013 John Wiley & Sons, Ltd. 相似文献
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