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由于受自然侵蚀和人类活动的影响,海岸带生态环境遭到破坏,正面临海岸线受损、湿地面积减少和植被退化等问题,如何实施生态修复保护海岸带已经成为沿海城市面临的重大机遇与挑战。构建滨海生态廊道正是保护海岸带的有效措施之一。生态廊道具有保护生物多样性、过滤污染物、调控洪水和连接景观斑块等多种生态功能,滨海生态廊道的构建可以缓冲海洋资源保护与城市发展之间的矛盾。文章以杭州湾北岸上海段为例,在上海市海洋保护修复和生态廊道建设的实践基础上,从廊道内部与外部空间、景观绿化和海洋生态基底等方面提出了一系列滨海生态廊道的具体指标和建议值,并结合杭州湾北段的生境现状,从廊道的生态功能与社会功能两方面提出构建滨海廊道的建议。 相似文献
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The relationship between body size and stable isotopic signatures of the omnivorous Redfin Culter(C ultrichthys erythropterus),commonly found in East Lake Taihu,was investigated. Previous analyses of C. erythropterus stomach contents have shown that this species undergoes a diet switch from being predominantly zooplanktivorous to piscivorous during its life history. This was confirmed by stable carbon isotopic signature(δ 13 C) in this study,in which δ 13 C was positively correlated with both standard length and weight. The importance of littoral-benthic resources in supporting C. erythropterus during its lifespan was also demonstrated using a two-source mixing model,the results of which showed a significant increasing trend in the contribution of littoral-benthic energy. However,the stable nitrogen isotopic signature(δ 15N) exhibited an unusual pattern compared with previous studies. The δ 15 N of C. erythropterus showed no relationship with body size,even though dietary changes were observed. This indicated that δ 15 N alone cannot fully reflect a diet shift in a species and possible variability in isotopic signatures over its life history. This should be considered when using stable isotopic signatures to investigate intra-specific variations and the timing of life-history events,such as estimating the trophic positions of fish species. 相似文献
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国务院参事、中国有色金属工业协会会长、党委书记陈全训近日表示,我国有色金属资源保障的局面仍然严峻重要有色金属矿产对外依存度逐年攀升,铜、铝、铅、锌原料大量依赖进口我国要进一步加大有色金属资源的回收综合利用,提高资源保障能力。陈全训在近日召开的全国有色金属矿业大会暨2012(第十届)有色金属矿业高层论坛上提出,加强有色金属矿业工作必须立足国内强化公益、依靠科技、加强管理。他说,我国是一个人口和资源大国不可能脱离自身资源禀赋追求资源安全。"实际上,国内很多矿产资源还没有充分开发利用,立足国内实现资源保障是有充分基础的。" 相似文献
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我国稀土战略收储工作已启动,国家财政资金将通过企业进行收储。这是我国首次启动国家稀土战略收储工作。此次收储原则为选择未来有重要应用但现在比较稀缺的产品,以及在市场价格低的时候进行一些战略性产品储备。去年5月发布的《国务院关于促进稀土行业持续健康发展的若干意见》提出,建立稀土战略储备体系。按照国家储备与企业(商业)储备、实物储备和资源(地)储备相结合的方式,建立稀土战略储备。此次收储就是有关部门按照国务院部署所进行的国家储备。 相似文献
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