多瑙河流域国际合作实践与启示

多瑙河是世界上流经国家最多的国际河流，其国际合作的成功实践对世界其他国际河流的合作具有积极的示范和借鉴作用。通过分析和总结多瑙河国际合作历程和合作特点（包括多种合作机制并存互补；引入风险管理、公众参与和流域综合管理等先进理念促进全面合作；利用GIS及数据管理等现代技术手段实现信息资源共享；利用协商和司法手段和平解决国际争端等），结合我国国际河流的特点和国际水法及国际河流合作的发展趋势，提出了对我国的启示：应加强国际河流相关方面的研究与合作（特别是航运与水电开发等）；应充分重视国际河流生态环境保护，生态环境保护和防洪越来越强调全流域的合作与协调；应坚持国际河流的开发利用与保护并举，走平衡发展之路；应根据各国际河流特点及地区条件，选择合适的管理合作模式.     

Knowing and Doing: Research Leading to Action in the Conservation of Forest Genetic Diversity of Patagonian Temperate Forests

Abstract:  Researchers dealing with conservation subjects usually do not put the results of their work into practice, even when the primary purpose of their research is the preservation of biodiversity. In the South American temperate forests we identified an area with the highest genetic diversity in Argentina of Nothofagus nervosa, one of the most relevant southern beech species. Based on the information of our scientific study and our recommendations, the authorities of Lanin National Park changed the protection status of this area to avoid logging. The new forestry management plans include consideration of "high genetic diversity" in decisions on where logging will be allowed. Results of our initial genetic study induced the analysis of biodiversity at the species and ecosystems levels, which yielded results similar to our genetic studies. A strong connection among researchers and managers from the onset of our study and the awareness of the former about the importance of the implementation of the research work were key to bridging the gap between conservation research and conservation practice.     

珠江三角洲水土资源开发利用问题与对策

本文全面分析了珠江三角洲水土资源开发利用的现状，阐明了水土资源开发利用中出现的环境问题及原因。因此，提出了该地区水土资源进一步合理开发利用的对策。     

Changes in wetlands on nonfederal rural land of the conterminous United States from 1982 to 1987

Recent wetland area trends were estimated from the National Resources Inventory (NRI) for nonfederal rural lands for the period 1982–1987. NRI-based estimates of wetland area for states comprising the conterminous United States were highly correlated with estimates made by the US Fish and Wildlife Service and with estimates of coastal salt marsh wetlands made by the National Oceanic and Atmospheric Administration. Net wetland area declined by 1.1% (≈363,200 ha) during the five-year study period. Conversion to open water, primarily caused by natural flooding in western inland basins, was responsible for altering extensive wetland areas (≈171,400 ha). Of the human-induced wetland conversions, urban and built-up land was responsible for 48% of the wetland loss, while agricultural development was indicated in 37% of the converted wetland area. A decrease in rural land, and increases in both population, and urban and built-up land were associated with wetland loss among states. Potential reasons for wetland loss were different in 20 coastal states than in 28 inland states. Proportionately, wetland loss due to development was three times greater in coastal states than inland states, while agriculturally induced wetland losses were similar in both groups. The proportionate declines of forested vs nonforested wetlands were not significantly different among states.     

Ecologically derived guidelines for managing two New Zealand lakes

Lakes Manapouri and Te Anau, in Fiordland National Park, became the center of a major controversy after the New Zealand government offered their water resource to an overseas aluminum smelting consortium for electricity generation. Although the scheme proceeded, the lake levels were not raised as originally proposed. Rather, government sought guidelines to optimize hydroelectric potential while maintaining ecological stability of the vulnerable, largely forested, glaciated lakeshores. Guidelines were derived by relating the vegetation zonation to the natural lake-level fluctuations recorded daily for 37 years. Ahigh operating range in the upper third of the lakes' natural ranges, based on flood tolerances of the woody shoreline species, restricts both duration and frequency. Alow operating range (ca. lower third) safeguards stability of shoreline sediments by limiting drawn-down rates, duration, and frequency. Themain operating range (ca. middle third) has few limitations. These guidelines, which allow utilization of ca. 93% of the water resource, have now been verified by instances of flooding and draw-down rates that exceeded the natural rates recorded earlier. The guidelines were officially accepted by the government in 1977 as a basis for managing the valuable multiple resources of these two lakes and their environs, and they were formalized in legislation in 1981. The details and merits of the guideline approach are discussed.     

Effects of labelled meaning on the affective quality of housing scenes

A series of studies examined the effects of labelled meaning on affective response to housing scenes. Students at Ohio State University assessed their feelings towards imagined housing (public or private) and cities (Memphis, Houston and San Francisco). Expected differences in the affective quality were found. Responses to color photographs of specific housing scenes labelled as either private condominiums or public housing were obtained. Differences in scene-affect as a function of labelled meaning were found. Responses to housing scenes labelled as located in either Memphis, Houston or San Francisco revealed no differences in scene-affect as a function of label meaning. This latter finding was confirmed in a non-repeated measure examination. Differences in the fittingness, potency or relevance of the information provided may account for the pattern of findings.     

Title 16 united states code §55 and its implications for management of concession facilities in Yosemite National Park

Yosemite National Park is one of the nation's most scenic and ecologically/geologically important parks. Unfortunately, the park is subject to extensive development of concession facilities and associated high levels of visitor use. Those concerned with preservation of the park's resources have attempted to limit the types and extent of such facilities to reduce adverse impacts. Strictly speaking, resolution of the preservation versus use controversy must be based on whether the National Park Service is adhering to its legislative mandate to regulate development and use in the parks. The common interpretation of legislative mandates for national parks, including Yosemite, is that they call for a difficult balancing between the conflicting goals of preservation and use. Accordingly, although concession developments cause significant impacts, they usually have been interpreted to be within the legal discretion allowed the secretary of the interior. However, the usual interpretations of the meanings of legislative mandates for Yosemite National Park have not considered Title 16 United States Code §55, which is a very restrictive statute limiting concession facilities. Many of the limitations imposed on concession facilities by the plain language of the statute have been exceeded. If it can be shown that 16 United States Code §55 is a valid statute, the policy implications for park management in Yosemite National Park would be considerable — namely, that significant reductions in concession facilities could be required. This article examines whether the statute can reasonably be thought to be valid and encourages others to conduct further examination of this question.     

External threats to ecosystems of US national parks

Activities beyond national park boundaries are now the principal source of threats to park natural resource integrity. Assessing the full impact of major threats as air and water pollution requires a long-term ecosystem-level approach in research design and execution, and park management. Failure to take such an approach renders most existing park data bases useless in the documentation of external threats. While the concept of managing national parks as ecosystems is not new, Park Service research and its organization have not provided the information necessary for such a basis of management. Quantifying the impacts on park resources due to external hydrologic regulation and air pollution is a good example of the need to employ an ecosystem approach in research. However, implementing such a program will require a fundamental change in research administration, priority setting, and conceptual approach.The first four of the articles in this special section arise from an AAAS symposium onExternal Threats to Ecosystems of the National Parks in the USA, which was convened in 1982. The articles have been revised to reflect subsequent developments in this field. The first article, by Dr. Stottlemyer, the symposium organizer, serves as an introduction to the topic. The fifth article in this special section was submitted separately, but included because it also is related to this particular topic.     

Legal considerations in challenging external threats to Glacier National Park,Montana, USA

External threats to the environmental integrity of Glacier National Park, Montana, USA, fit into three categories: adverse land use practices adjacent to the Park, air pollution, and water pollution. This article identifies and evaluates the laws that Glacier National Park officials might rely upon to protect the Park against these external threats. The article also assesses the available scientific information relating to external threats, and it identifies additional information needed to establish a legal basis for challenging the threats.     

Recreational impacts on backcountry campsites in Grand Canyon National Park,Arizona, USA

Backcountry campsites were studied in three desert vegetation types (pinyon-juniper, catclaw, and desert scrub) in Grand Canyon National Park, Arizona. Relationships between amount of use and amount of impact were examined within each vegetation type. The area disturbed was small, but impacts were generally severe. Important impacts were increased soil compaction and associated decreases in infiltration rates and soil moisture content; these were substantially more pronounced on high than low use sites. The only impact parameter that differed significantly between vegetation types was core area. The types of impact identified are similar to those found in the coniferous forests studied elsewhere, as is the logarithmic relationship between amount of use and amount of impact. However, Grand Canyon sites can support more visitor use before reaching near-maximum levels of impact for important impact parameters.