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Age Structure and Growth of Degraded Populus euphratica Floodplain Forests in North-west China and Perspectives for Their Recovery 被引量:10
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作者 Janneke Westermann Stefan Zerbe dieter eckstein 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2008年第5期536-546,共11页
The Populus euphratica floodplain forests along the lower reaches of the Tarim River in continental-arid Xinjiang (northwest China) have been declining in recent decades as a result of dam constructions and the with... The Populus euphratica floodplain forests along the lower reaches of the Tarim River in continental-arid Xinjiang (northwest China) have been declining in recent decades as a result of dam constructions and the withdrawal of water from the river. Since 2000, controlled flooding has been carried out to counteract this process of degradation. However, the consequences of a changing water regime for the floodplain ecosystem are not yet sufficiently investigated. In 2004 we sampled a total of 150 P. euphratica trees along two transects at the middle and lower reaches of the Tarim River to compare the age structure and growth of these two tree populations. The anthropogenic drawdown of the groundwater table had no effect on the average growth of the trees at the lower reaches. However, tree growth abruptly increased after controlled flooding, thus showing distinct signs of recovery. 展开更多
关键词 arid land controlled flooding Euphrates poplar human impact Populus euphratica tree rings.
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机械制造行业的认证
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作者 dieter eckstein 蔡玉巧 《标准生活》 1996年第1期19-22,共4页
为了使广大读者客观、全面、及时地了解国际上热门话题——质量认证的历史现状与发展,本刊将连续刊登由国际知名的德、英、法、日、瑞士、葡萄牙等国家的质量专家撰写的专题文章,欢迎国内读者发表意见,介绍经验。
关键词 机械制造业 认证机构 技术监督 机械指令 生产厂家 欧共体委员会 统一市场 标志 立法机构 技术水平
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