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91.
地球表面的2/3为海洋所覆盖,我们生存所需的氧70%由海洋提供,面对气候变化及其他威胁,我们该如何去保护海洋呢?做下面的测试去找找答案吧。1、珊瑚白化是指:A.专业的潜水员为游客清洗和漂白珊瑚礁。B.珊瑚虫排出藻类致使珊瑚礁变白的过程。C.年深日久珊瑚会掉 相似文献
92.
多年前,他在位于落基山脉亚高山地带的露营场采访时,看到路边的标牌上写着:"请把花留给别人欣赏。"后来这块木牌的标志被腐蚀,一片一片地剥落,于是新的标志代替了这些旧的标志,上面写着:"让花儿继续活下去。"——《生命的未来》尽管和梭罗(Henry DavidThoreau,1817-1862)相隔112岁之遥,声名卓著的生物学家爱德华·威尔逊(Edward Osborne Wilson,1929-)博士还是坚持给业已作古的梭罗写了一封永远无法寄达的长信,放在其2002年出版的著作《生命的未来》(The Future of Life)一书的卷首, 相似文献
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通过对生态系统健康评价体系的研究,以沙湖为例进行论证,最终得出沙湖生态系统健康度为0.32,属于不健康,制约沙湖不健康的疾病因子在于:湿地的补水水质差,导致湿地水质污染加重,富营养化现象严重,并且由于人为因素,导致物种多样性逐年下降,以上因素最终导致了沙湖湿地生态系统抗干扰能力下降,湖区湿地健康水平较低,根据对沙湖湿地功能的分析,最终设计出了沙湖湿地生态系统健康恢复技术方案。 相似文献
96.
A restoration-promoting integrated floating bed and its experimental performance in eutrophication remediation 总被引:5,自引:0,他引:5
Yiming Guo Yunguo Liu Guangming Zeng Xinjiang Hu Xin Li Dawei Huang Yunqin Liu Yicheng Yin 《环境科学学报(英文版)》2014,26(5):1090-1098
Numerous studies on eutrophication remediation have mainly focused on purifying water first, then restoring submerged macrophytes. A restoration-promoting integrated floating bed (RPIFB) was designed to combine the processes of water purification and macrophyte restoration simultaneously. Two outdoor experiments were conducted to evaluate the ecological functions of the RP1FB. Trial 1 was conducted to compare the eutrophication purification among floating bed, gradual-submerging bed (GSB) and RPIFB technologies. The results illustrated that RPIFB has the best purification capacity. Removal efficiencies of RPIFB for TN, TP,NH4+-N, NO3-N, CODcr, Chlorophyll-a and turbidity were 74.45%, 98.31%, 74.71%, 88.81%, 71.42%, 90.17% and 85%, respectively. In trial 2, influences of depth of GSB and photic area in RPIFB on biota were investigated. When the depth of GSB decreased and the photic area of RPIFB grew, the height of Potamogeton crispus Linn. increased, but the biomass of Canna indica Linn. was reduced. The mortalities of Misgurnus anguillicaudatus and Bellamya aeruginosa in each group were all less than 7%. All results indicated that when the RPIFB was embedded into the eutrophic water, the regime shift from phytoplankton-dominated to macrophyte-dominated state could be promoted. Thus, the RPIFB is a promising remediation technology for eutrophication and submerged macrophyte restoration. 相似文献
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Qinqin Lou Yinfeng Zhang Dongkai Ren Haiming Xu Yaxian Zhao Zhanfen Qin Wuji Wei 《环境科学学报(英文版)》2014,26(10):2084-2094
Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone(TH) signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor(TR) agonist(T3) and antagonist(amiodarone) by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility. 相似文献
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在分析干流河岸带现状及生境区域的基础上,阐述了辽河保护区河岸带的生态恢复对策、方法及技术。辽河保护区河岸带生态恢复应根据其特点确定河岸缓冲带的宽度,筛选适宜的植被类型,进行缓冲带的生态结构设计,重建河岸缓冲带草生、草灌、林木阻控带等植物群落系统。辽河保护区河岸缓冲带最小有效宽度设置为30 m,当河岸斜坡所占缓冲带比例15%时,河岸缓冲带宽度增加15 m。在河岸带生态系统恢复方法上,辽河保护区福德店—三河下拉段、柳河口—盘山闸段采用正常恢复法,清河口—拉马河口段采用坑塘湿地为主恢复,三河下拉—清河口段采用牛轭湖湿地为主恢复,石佛寺—柳河口段采用自然湿地为主恢复。 相似文献
100.
辽河保护区在清河口—马虎山段100多km河道上的沙坑为建设坑塘湿地提供了基本条件,阐述了辽河保护区坑塘湿地恢复方法、水系连通技术、生态系统恢复技术及建设工程设计方案。在铁岭段、沙宝台段和石佛寺段建设30个坑塘湿地,通过修建宽2~3 m的连通渠实现坑与坑及坑与河道之间的水系流动,可形成三大坑塘湿地群。通过湿地下垫面整治、植被恢复、生境恢复及水文调控与管理恢复坑塘湿地生态系统,通过河流湿地水网建设和水生植物群落重建工程进行坑塘湿地建设,能够实现对干流悬浮物、COD Cr和氨氮的有效去除,增加蓄水量909万m3,有效改善辽河流域生态环境。 相似文献