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王兆锋 《中国人口.资源与环境》2008,18(2):29-34
旅游产业集群的生态属性研究已经成为当前的热点。当前利用生态理论研究旅游产业集群的发展规律.对我国旅游产业集群的健康发展具有非常重要的意义。本文基于生态理论。从旅游产业集群的发展特征出发,认为旅游生态资源潜力、集群生态成长机制、集群生态外部环境等是影响其发展的主要因素.据此选择集群生态资源潜力、集群生态结构、集群外部环境等指标。将旅游产业集群生命周期分为旅游产业集群形成、发展、成熟、衰退——转型等四个阶段,并分析了各个发展阶段的特点。最后提出开拓旅游产业集群生态营养源泉、构建旅游产业集群与其生态环境的和谐互动机制、维护旅游产业集群内部生态平衡等相关的建议。 相似文献
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Dong Jihong 《中国人口.资源与环境(英文版)》2007,5(4):85-91
The main purpose of this study is to put forward a reasonable idea of the general protection for Singing Sand Mountain and Crescent Moon Spring, a rare and unique desert wonder, and of sustainable tourism development based on the research on the ecological environment around. Methods of documentation, case study and comparison were employed. Finally, aiming at solving the problems of natural environment and those existing after the exploitation of Singing Sand Mountain and Crescent Moon Spring the author puts forward three measures: the comprehensive treatment for Crescent Moon Spring (broadening resources of water and reducing expenditures, checking the decreasing depth of Crescent Moon Spring, and improving the geographical environment), the general protection envisions for Singing Sand Mountain and Crescent Moon Spring and establishing a dynamic monitoring and early-warning system of regional ecosystem. 相似文献
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武汉东湖水生植被现状调查及群落演替分析 总被引:20,自引:0,他引:20
对东湖水生植物的调查结果表明,东湖现存水生维管束植物共计20科25属33种,其生物量约为1.137t,分布面积仅占东湖总面积的0.7%,其中挺水植物分布面积占总面积的98%。与1957年、1962~1963年和1988~1994年相比,东湖水生植物的种类、分布面积和生物量进一步减少。认为造成东湖水生植被衰退的主要原因包括富营养化作用加剧、过度放养草食性鱼类和人类活动的影响。 相似文献
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WANG Jun GUO Bao-dong ZHANG Zhao-hong ZHANG Xiang-dong WU Jing LI Hong 《环境科学学报(英文版)》2005,17(3):414-418
The nanometer and ordinary anatase titanium dioxide(TiO2 ) powders were adopted as the sonocatalysts for the degradation of methyl orange used as a model compound for the first time. It was found that the sonocatalytic degradation effect of methyl orange in the presence of TiO2 powder were much better than that without TiO2, but the sonocatalytic activity of the nanometer anatase TiO2 particle was obviously higher than that of ordinary anatase TiO2 particle. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results showed that the best degradation ratio of methyl orange could be obtained when the experimental conditions were: initial concentration 15 mg/L, nanometer anatase TiO2 adding amount 750 mg/L, ultrasonic frequency 40 kHz, output power 50 W, pH = 3.0 and temperature 40℃ within 150 min. In addition, the catalytic activity of reused nanometer anatase TiO2 catalyst was also studied and found to decline gradually comparing with initial nanometer anatase TiO2 catalyst. All experiments indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO2 powder was an advisable choice for non-or lowtransparent organic wastewaters. 相似文献
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IntroductionManykindsofalgaecanleadtowaterbloomandredtideintheseas ,lakesandreservoirs .Thisphenomenoninfluencesorchangesthephysicalandchemicalcharacterofwaterandthenresultsinmanytroubleinthedrinkingwaterproductionprocess(Hargensheimer,1996;Graham ,1997;M… 相似文献
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最近1份英国政府报告称,气候变化有可能导致20世纪30年代经济大衰退以来最坏的衰退。该报告说,到2050年气候变化导致的损失将相当于世界总产值(GDP)的5%~20%。为避免这一情况发生,到2050年应将温室气体排放比1990年减少60%~80%,其费用只相当于全球GDP的1%。报告说,现在还有时间去行动以避免最坏影响,但如推迟采取措施,哪怕只是10、20年,也会把人类带入危险境地。 相似文献
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为了研究滇池流域沉水植物衰退和消失的驱动因子,该文通过室内控制培养沉水植物黑藻、金鱼藻和篦齿眼子菜,结合沉水植物野外调查数据、水质监测数据和相关数理统计分析结果,定量分析导致沉水植物死亡衰退的驱动因子及其浓度阈值。研究结果表明氨氮是驱动沉水植物分布和群落结构变化的主导因子,氨氮与沉水植物种类的相关性最大,且呈负相关。高浓度的氨氮导致沉水植物黑藻、金鱼藻和篦齿眼子菜死亡,且p H值升高时导致沉水植物死亡的氨氮浓度阈值降低。随着p H值从7升至8.5,导致黑藻死亡的氨氮浓度最低值从12 mg/L下降到2 mg/L,且导致黑藻全部死亡的氨氮浓度最低值从高于16 mg/L下降至6 mg/L,导致金鱼藻死亡的氨氮浓度最低值从高于16 mg/L下降到3 mg/L,导致篦齿眼子菜死亡的氨氮浓度最低值从高于16 mg/L下降到8 mg/L,即氨氮和p H的协同作用加快了沉水植物死亡衰退的速率。因此,氨氮和p H的协同作用是沉水植物的衰退和消失的驱动因素,且p H值越高,驱动作用越明显。 相似文献