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291.
The attitudes and behaviours of private landholders toward the conservation of a highly transformed and critically endangered
habitat, Overberg Coastal Renosterveld (OCR) (a grassy shrubland of the Cape Floral Region, South Africa) are described. Personal,
semistructured interviews were conducted with landholders, representing 40 properties in the Overberg region, on topics such
as management and utilisation of OCR, the depth of their knowledge of its conservation importance, what they perceive its
value to be, and the extent of their willingness to conserve it. General attitudes toward conservation incentives and provincial
conservation authorities were also investigated. Farmers more willing to conserve were younger, did not necessarily have a
better education, and owned larger farms (>500 ha) with a greater amount of remnant renosterveld (>300 ha) than those less
willing to conserve. Attitudes toward the OCR were largely negative, related to associated problem plants and animals and
the fact that it is believed not to be economically advantageous to retain it. However, farmers are of the opinion that provision
of incentives and increased extension support will provide practical positive inducements for conservation. Landholder education
is paramount to prevent further transformation of critically endangered habitats. The success of private-conservation programs
depends on the attitudes of landowners toward (1) the particular habitat or species to be conserved (which can vary depending
on the type of land use practised and the associated benefits and disadvantages of that habitat type); (2) the conservation
agency or extension officers responsible for that area; and (3) willingness of landowners to participate in a conservation
program, which is influenced by landowner age, farm size, and the amount of natural habitat left to conserve. 相似文献
292.
Danz NP Niemi GJ Regal RR Hollenhorst T Johnson LB Hanowski JM Axler RP Ciborowski JJ Hrabik T Brady VJ Kelly JR Morrice JA Brazner JC Howe RW Johnston CA Host GE 《Environmental management》2007,39(5):631-647
Integrated, quantitative expressions of anthropogenic stress over large geographic regions can be valuable tools in environmental research and management. Despite the fundamental appeal of a regional approach, development of regional stress measures remains one of the most important current challenges in environmental science. Using publicly available, pre-existing spatial datasets, we developed a geographic information system database of 86 variables related to five classes of anthropogenic stress in the U.S. Great Lakes basin: agriculture, atmospheric deposition, human population, land cover, and point source pollution. The original variables were quantified by a variety of data types over a broad range of spatial and classification resolutions. We summarized the original data for 762 watershed-based units that comprise the U.S. portion of the basin and then used principal components analysis to develop overall stress measures within each stress category. We developed a cumulative stress index by combining the first principal component from each of the five stress categories. Maps of the stress measures illustrate strong spatial patterns across the basin, with the greatest amount of stress occurring on the western shore of Lake Michigan, southwest Lake Erie, and southeastern Lake Ontario. We found strong relationships between the stress measures and characteristics of bird communities, fish communities, and water chemistry measurements from the coastal region. The stress measures are taken to represent the major threats to coastal ecosystems in the U.S. Great Lakes. Such regional-scale efforts are critical for understanding relationships between human disturbance and ecosystem response, and can be used to guide environmental decision-making at both regional and local scales. 相似文献
293.
I. A. Akpabio E. A. Eniang E. C. Egwali 《Environment, Development and Sustainability》2008,10(3):249-265
This study examines the present environmental and socio-economic status of Adiabo Community in Odukpani Local Government Area
of Cross River State against the background of the proposal of the Cross River State Government to site a tourism resort in
the community. The paper utilizes participatory appraisal techniques to document information on the existing environmental
and socio- economic structure of the study area. It also analyses the potential effect of the proposed tourist resort on the
community dwellers and finally recommends strategies to ensure the sustainability of the proposed project and livelihood activities
of the natives in the study area. 相似文献
294.
295.
F. A. Kohout J. C. Hathaway D. W. Folger M. H. Bothner E. H. Walker D. F. Delaney M. H. Frimpter E. G. A. Weed E. C. Rhodehamel 《Journal of the American Water Resources Association》1977,13(2):373-386
ABSTRACT: A deep water-resource and stratigraphic test well near the center of Nantucket Island, about 40 miles (64 km) off the New England Coast, has encountered freshwater at greater depth than predicted by the Ghyben-Herzberg principle. An uppermost lens of fresh-water, which occupies relatively permeable glacial-outwash sand and gravel to a depth of 520 ft. (158 m), is probably in hydrodynamic equilibrium with the present level of the sea and the height of the water table. However, two zones of freshwater between 730-820 ft. (222-250 m) and 900-930 ft. (274-283 m) are anomalously deep. A third zone extending from 1150-1500 ft. (350-457 m) contains slightly salty ground water (2 to 3 parts per thousand dissolved solids). Several explanations are possible, but the most likely is that large areas of the Continental Shelf were exposed to recharge by precipitation during long periods of low sea level in Pleistocene time. After the last retreat of glacial ice, seawater rapidly drowned the shelf around Nantucket Island. Since then, about 8000 years ago, the deep freshwater zones which underlie dense clay layers have not had time to adjust to a new equilibrium. Under similar circumstances freshwater may remain trapped under extensive areas of the Continental Shelf wherever clay confining beds have not permitted saltwater to intrude rapidly to new positions of hydrodynamic equilibrium. The implications are far reaching because all continental shelfs were exposed to similar hydrologic influences during Pleistocene time. 相似文献
296.
江津润湿时间的温度分布研究 总被引:3,自引:1,他引:2
采用直接读取、4点统计、24点统计三种方法研究了江津试验站1998年的润湿时间的温度分布,研究表明,可以利用全年每天2、8、14、20点的4个数据统计年润湿时间的温度分布;江津地区润湿时间的温度分布特征主要为:(1)99%的年润湿时间是在5℃至30℃温度范围,每月润湿时间的温度波动一般为15℃;(2)在(0~5)℃、(5~10)℃、(10~15)℃、(15~20)℃、(20~25)℃、(25~30)℃、(30~35)℃区间内,4点统计法各区间润湿时间的百分比分别为0.34%、13.4%、24.5%、18.3%、26.0%、17.4%、0.0%。 相似文献
297.
纳氏试剂光度法测定废水中氨氮的问题讨论 总被引:1,自引:0,他引:1
应用纳氏试剂比色法测定废水中的氨氮时,水样显色后稳定时间短,影响测定结果的准确性,针对这一问题进行了实验研究。实验中对主要影响因素I-和OH-的浓度变化进行了条件实验,结果表明选用所配的Ⅲ型纳氏试剂(KI含量为7.5g),可获得稳定的有色胶体,也可采用Ⅰ型纳氏试剂(KI含量为7.0g)、在中和硼酸后再多加2mLNaOH(1mol/L),也可获得稳定的有色胶体。 相似文献
298.
复合系统的协调与可持续发展 总被引:25,自引:0,他引:25
本文从“生态—社会—经济”复合系统协调的角度探讨可持续发展问题,提出了复合系统定义下可持续发展的系统观点及系统特征,建立了概念模型,根据协调理论,分析了可持续发展的系统协调原则及内容 相似文献
299.
Joanna Burger 《Environmental management》1998,22(6):869-876
/ Management of ecosystems has advanced by an improvement in our understanding not only of how ecosystems function, but of how people perceive their functioning and what they consider to be environmental problems within those systems. Central to such management is understanding how people view estuaries. In this article I explore the perceptions and attitudes of people about coastal recreation, environmental problems, and future land use along the New Jersey shore (USA) by interviewing people who attended a duck decoy and craft show on Barnegat Bay. The people who were interviewed engaged in more days of fishing than any other recreational activity and engaged in camping the least. There were significant differences in recreational rates as a function of gender and location of residence, with men hunting and fishing more than women and photographing less than women. Jet skis were perceived as the most severe environmental problem, with chemical pollution, junk, oil runoff and overfishing as second level problems. Birds were perceived as not an environmental problem at all. Fishing, hiking, preservation, and camping ranked as the highest preferred future land uses for the two sites examined (Oyster Creek Nuclear Generating Station, Naval Weapons Station Earle). The preferred future land uses for these two sites, which are not under consideration for land-use changes, were very similar to those of people living near the Department of Energy's Savannah River Site in South Carolina, despite the media attention and considerations of nuclear storage.KEY WORDS: Recreation; Perceptions; Environmental problem; Gender; Land use; Coastal 相似文献
300.
海平面上升对海岸带环境的影响与危害及其防治对策 总被引:5,自引:1,他引:5
本文阐述了过去近百年来和未来特定年份海平面上升的趋势,分析了海平面上升的原因及其对海岸带环境的影响与危害,最后提出了防治对策与措施。 相似文献