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251.
入湖溪流对西湖富营养化的影响调查 总被引:1,自引:0,他引:1
陆莹 《环境监测管理与技术》2000,(Z1)
分析了西湖水质现状 ,指出入湖溪流的水质不佳是目前西湖保持富营养化状态的重要原因。提出了相应的对策建议。 相似文献
252.
关于中国西部“山川秀美”再造的思考——兼论西部生态安全建设中的防灾减灾 总被引:1,自引:0,他引:1
再造一个“山川秀美”的大西北 ,展现出一幅理想的人与自然依存的场景。笔者为此给出独特的思考和科学的见解 :要实现这一目标 ,必须研讨“山川秀美”的科学内涵 ,以恢复大西北自然生态安全环境为基础 ,以防灾减灾 ,保护人与自然为手段 ,依靠科技进步 ,坚持可持续发展战略 ,从长远利益并结合地区实际 ,才能真正实现人与自然和谐共存的“山川秀美” 相似文献
253.
西部大开发与聚落生态建设——以西南山区为例 总被引:2,自引:0,他引:2
陈国阶 《生态与农村环境学报》2001,17(2):5-8
我国西部生态环境退化与广泛分布的农村聚落落后的生产方式和生活方式有密切关系。在西部大开发中 ,搞好生态环境必须与聚落建设统一规划 ,同步实施。重点应解决好环境恶劣的聚落、地方病聚落、自然保护区聚落、草场聚落、工程移民聚落。根据不同生态状况 ,可采取新建聚落、重建聚落与迁建聚落等聚落建设方略 相似文献
254.
为促进西部大开发战略的实施和西部地区可持续发展 ,就西部地区环境政策框架和环境管理能力建设两方面进行了初步研究 ,提出了一些建议 相似文献
255.
This paper analyzes livelihood change and livelihood sustainability of households in the upland part of the Lembang subwatershed,
West Sumatra, in response to changes in the natural resource management context during the last decade. Using the sustainable
livelihood framework (SLF), we measured livelihood changes at two separate points in time, 1996 and 2006, and assessed their
environmental, economic, social, and institutional sustainability. We found that people with a low income had less access
to capital assets than people from middle- and high-income groups. Our analysis revealed, however, that access to capital
assets increased over time, and that poor households experienced economic improvement, indicating an overall increase in economic
sustainability. Environmental sustainability, however, is threatened by intensive agricultural practices such as high agrochemical
input and intensive soil tillage on steep slopes, leading to pollution and soil erosion. Social sustainability is also a matter
of concern: while social exclusion has been reduced, income inequity has increased. Institutional sustainability is likely
to remain uncertain, as local institutions for natural resource management are still weak, despite the fact that decentralization
has been implemented during the last 8 years. External facilitation is needed to improve the livelihood of upland people while,
at the same time, enhancing the sustainability of watershed management. Strengthening local institutions, conserving natural
resources, and promoting environmentally sound agricultural practices are the three most important policies to be promoted
within the watershed. 相似文献
256.
Hemlock Woolly Adelgid (Adelges tsugae) is spreading across forests in eastern North America, causing mortality of eastern hemlock (Tsuga canadensis [L.] Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.). The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) may result in significant
physical, chemical, and biological alterations to stream environments. To assess the influence of riparian hemlock stands
on stream conditions and estimate possible impacts from hemlock loss in GSMNP, we paired hardwood- and hemlock-dominated streams
to examine differences in water temperature, nitrate concentrations, pH, discharge, and available photosynthetic light. We
used a Geographic Information System (GIS) to identify stream pairs that were similar in topography, geology, land use, and
disturbance history in order to isolate forest type as a variable. Differences between hemlock- and hardwood-dominated streams
could not be explained by dominant forest type alone as forest type yields no consistent signal on measured conditions of
headwater streams in GSMNP. The variability in the results indicate that other landscape variables, such as the influence
of understory Rhododendron species, may exert more control on stream conditions than canopy composition. The results of this study suggest that the
replacement of hemlock overstory with hardwood species will have minimal impact on long-term stream conditions, however disturbance
during the transition is likely to have significant impacts. Management of riparian forests undergoing hemlock decline should,
therefore, focus on facilitating a faster transition to hardwood-dominated stands to minimize long-term effects on water quality. 相似文献
257.
258.
通过野外考察、标本采集、资料查阅整理及标本鉴定,对乌蒙山山脉药用植物资源进行了调查。结果表明,乌蒙山山脉共有药用植物272科1189属3184种(含变种和亚种),其中地衣植物8科9属13种、苔藓植物40科74属116种、蕨类植物45科108属358种、裸子植物10科22属37种、被子植物169科976属2660种。对其物种组成、生态类型、分布、优势科属、药用部位、功效等进行了统计分析,对常用中药、国家重点保护野生药材、民间习用药物进行了简要介绍,并对其开发利用提出了建议。 相似文献
259.
Despite the popularity of tourism and recreation in the Andes in South America and the regions conservation value, there is limited research on the ecological impacts of these types of anthropogenic use. Using a systematic quantitative literature review method, we found 47 recreation ecology studies from the Andes, 25 of which used an experimental design. Most of these were from the Southern Andes in Argentina (13 studies) or Chile (eight studies) with only four studies from the Northern Andes. These studies documented a range of impacts on vegetation, birds and mammals; including changes in plant species richness, composition and vegetation cover and the tolerance of wildlife of visitor use. There was little research on the impacts of visitors on soils and aquatic systems and for some ecoregions in the Andes. We identify research priorities across the region that will enhance management strategies to minimise visitor impacts in Andean ecosystems.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-014-0550-7) contains supplementary material, which is available to authorized users. 相似文献260.
The effect of nitrogen additions on oak foliage and herbivore communities at sites with high and low atmospheric pollution 总被引:2,自引:0,他引:2
Eatough Jones M Paine TD Fenn ME 《Environmental pollution (Barking, Essex : 1987)》2008,151(3):434-442
To evaluate plant and herbivore responses to nitrogen we conducted a fertilization study at a low and high pollution site in the mixed conifer forests surrounding Los Angeles, California. Contrary to expectations, discriminant function analysis of oak herbivore communities showed significant response to N fertilization when atmospheric deposition was high, but not when atmospheric deposition was low. We hypothesize that longer-term fertilization treatments are needed at the low pollution site before foliar N nutrition increases sufficiently to affect herbivore communities. At the high pollution site, fertilization was also associated with increased catkin production and higher densities of a byturid beetle that feeds on the catkins of oak. Leaf nitrogen and nitrate were significantly higher at the high pollution site compared to the low pollution site. Foliar nitrate concentrations were positively correlated with abundance of sucking insects, leafrollers and plutellids in all three years of the study. 相似文献