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461.
A total of 25 scenes representing the five visual quality objectives in the US Department of Agriculture Forest Service visual management system were presented to 18 professional and public interest groups in western Montana. The results indicate that nearly all the groups have similar rank orderings of the scenes in terms of visual preference. However, the groups differ according to the absolute values of their ratings. Most groups were unable, in a statistical sense, to differentiate the scenic quality of areas in the preservation and retention visual quality objectives. Landscape architects tended to rate scenes in a way similar to professional forest management groups. 相似文献
462.
463.
Monica Goigel Turner 《Environmental management》1987,11(2):237-247
Land use since 1935 was quantified for Georgia, USA, and for a sample of 20 counties from the major physiographic regions within the state. Statistical data on crop production, pasture productivity, and forest growth were used to estimate net primary production. Appropriate harvest indices (ratio of crop yield to total plant production) were used to correct crop yield data for different decades. Net primary production (NPP) of the Georgia landscape increased from 2.5 to 6.4 tonnes/ha from 1935 to 1982, but varied considerably among land uses and physiographic regions. NPP in the piedmont and mountains reached a plateau between 1960 and 1982, but the upper and lower coastal plains showed a continued linear increase in NPP. In all regions, NPP rose most between 1960 and 1982, coinciding with increases in inputs such as fertilizer and irrigation. Natural ecosystem NPP for Georgia is approximately 16–18 tonnes/ha, and the estimated actual NPP is thus considerably less than the potential. Spatial and temporal patterns of NPP may be a useful basis for evaluating the biological performance of a landscape. 相似文献
464.
Ian C. Laurie 《Journal of Environmental Planning and Management》1985,28(2):86-91
The country estate has a particular place in the English countryside and its contribution to the landscape scene is distinct and valuable. The paper describes an approach to planning a large country estate of parkland, woodland and estate villages in Cheshire. A Reconnaissance Survey led to the Outline Strategy for six ‘landscape types’ discovered on the estate. The Landscape Conservation Plan is described and the crucial importance of conservation measures is emphasised. 相似文献
465.
A landscape-level approach was applied to eight rural watersheds to assess the role that wetlands play in reducing phosphorus loading to surface waters in the Lake Champlain Basin. Variables summarizing various characteristics of wetlands within a watershed were calculated using a geographic information system and then compared to measured phosphorus loading through multiple regression analyses. The inclusion of a variable based on the area of riparian wetlands located along low- and medium-order streams in conjunction with the area of agricultural and nonwetland forested lands explained 88% of the variance in phosphorus loading to surface waters. The best fit model coefficients (Pload = 0.86Ag + 0.64For – 30Ripwet + 160) suggest that a hectare of riparian wetland may be many times more important in reducing phosphorus than an agricultural hectare is in producing phosphorus. These results provide additional support for the concept that protection of riparian wetlands is an important management strategy for controlling stream water quality in multiuse landscapes. 相似文献
466.
为了从价值观和调节焦点的双重视角给煤矿企业新生代员工的安全管理提供科学依据,在文献研究和问卷调查的基础上,对 244 个有效样本进行分析,揭示煤矿企业新生代员工工作价值观的具体内容,结合动机理论和调节焦点理论,构建煤矿企业新生代员工工作价值观、调节焦点和安全绩效的结构方程模型。研究结果表明:煤矿企业新生代员工的工作价值观包含发展导向、自我导向、关系认同、独立自主、利益导向和创造导向6个因子结构;煤矿企业新生代员工的工作价值观、调节焦点和安全绩效两两之间均显著相关;煤矿企业新生代员工的工作价值观不仅可以直接预测安全绩效,还可以通过调节焦点的中介作用间接影响煤矿员工的安全绩效。 相似文献
467.
In both predictive theoretical and empirical models for aquatic plant communities in running waters, the development and competition are many times explained in terms of nutrients. Minerals necessary for growth are generally not assumed to be limiting, although they influence the important pH-value. At the same time it is known that factors such as oxygen-concentration, solar energy, salinity, dimension of the system and soil characteristics (including river sediments) influence the development of the community, and should be considered in modelling. Effects of water quantity and water quality on macrophytes are reviewed. These conditions are caused by processes in the landscape, characterised by a set of nested variables which explain the distribution of macrophyte species and communities. Relevant variables are described and grouped on three scales: regional, local and site conditions. Case studies with direct and indirect gradient analysis are presented. Statistical tests (stepwise regression with forward selection) reveal that each species distribution is explained by a characteristic set of relevant variables, ranging from soil type and dimension of the system, to nutrient and salinity concentration. 相似文献
468.
H. Doing 《Journal of Coastal Conservation》1995,1(2):145-172
This paper is a summary and elaboration of an earlier publication in Dutch on the compilation of a landscape-ecological map,
scale 1 : 50 000, of the Dutch coast. It is argued that such an integrated map is the best basis for the conservation and
management of the coastal dunes and salt marshes. It may be combined with local more detailed vegetation maps, some examples
of which are mentioned in the context of management.
The Dutch North Sea coast is a ca. 350 km long chain of sandy beaches and sand dunes, from only 100 m to more than 10 km wide.
On sheltered stretches of dune coasts along estuaries in the Southwest and on the Wadden Sea islands, salt marshes have developed.
The small-scale gradient structure of the beach-dune-salt marsh complex is emphasized. 相似文献
469.
景观生态学与荒漠生态环境监测 总被引:2,自引:0,他引:2
通过对景观生态的阐述,在讨论荒漠生态环境监测的概念、对象、内容、方法和目的的基础上,分析了景观生态学成为荒漠生态环境监测理论和实践的基础的可能性和必要性,指出景观生态学在荒漠生态环境监测中的应用大有可为。 相似文献
470.
Sümer Gülez 《Environmental management》1996,20(1):113-122
The study consists of two parts. One part deals with recreation and vacation demands; the other investigates the relationship
between recreation demand and some natural landscape elements preferred in the eastern Black Sea coastal zone of Turkey, which
has traditionally a rich recreational culture. Home interview surveys were conducted during the summer of 1992. The recreation
demand of the study area has been found to be 89.3% including potential demand. The landscape element "sea and seaside" preferred
for recreation has been rated the highest in all groups of each of the five variables, namely, age, education, income, occupation,
and marital status. The research reported here represents an empirical contribution to the field of landscape preference studies
for recreation, especially in the developing countries. 相似文献