中晚全新世以来闽江口水下三角洲物质来源及古环境演变

通过对闽江口南侧柱状样沉积物开展高分辨率的粒度、粘土矿物分析及AMS¹⁴C测年,揭示了中晚全新世以来闽江口水下三角洲物质来源及古环境演变。中全新世(7 ka BP—4 ka BP)高海平面时期,梅花水道可能是闽江口南侧陆源物质输运的主要通道,沉积了以砂为主[(58.6±8.7)%]的沉积物,平均粒径为(3.76±0.49)φ,为较高能的沉积环境。期间,增强的浙闽沿岸流携带更多的长江物质沉积到闽江口,导致沉积物中蒙脱石含量增多。然而,到晚全新世(3 ka BP)海平面略有下降,梅花水道衰退,闽江口南侧的水动力条件减弱,形成以粉砂为主[(58.1±4.4)%]的沉积物,平均粒径为(6.30±0.32)φ。晚全新世浙闽沿岸流有所减弱,闽江口沉积物中的蒙脱石含量明显减少,而来自闽江的高岭石含量增加。     

恢复图们江出海权对东北亚区域经济政治和我国东北地区的影响和对策

为充分发挥图们江特殊地理位置的重要作用,促进国际和国内区域发展,文章分析恢复图们江出海权对东北亚区域经济政治和我国东北地区的影响,并提出对策建议。研究结果表明：我国恢复图们江出海权具有法理依据和现实需求;恢复图们江出海权对东北亚区域的能源和资源合作开发、中蒙俄经济走廊建设、环日本海国家经济合作以及东北亚区域政治格局具有重要影响,同时有利于我国东北地区维护边境地区安全、促进海洋经济发展、振兴东北老工业基地、打造海运通道和平衡区域经济发展;我国应抓住历史机遇,积极借助国际组织力量、对接各国发展需求以及以经济发展取代政治分歧,尽快恢复图们江出海权,为国际和国内区域发展提供保障。     

闽江口及周边海域沉积物输运及资源效应

河流入海泥沙的大部分主要分布在河口、三角洲及近岸陆架地区,发育一系列的粗颗粒沉积体系,是海砂资源重要分布区。本文以福建闽江口为研究对象,初步探讨了沉积物输运过程及海砂资源的形成机制。观测结果表明,闽江河口水体盐度由河口内部向口外海域逐渐增大,水体浊度总体减小;闽江河口附近海域近底部(距离海底25cm)流向表现出一定的旋转流特征,潮周期内余流表现为向海输运,而推移质输运主要发生在涨潮期间,并且潮周期内净向陆输运。表层沉积物粒度分析结果表明,闽江河口水下三角洲前缘表层沉积物主要由粗颗粒物质组成,沉积物类型以砂和砂质粉砂为主,中值粒径小于4Φ;前三角洲地区表层沉积物主要由细颗粒物质组成,中值粒径介于4Φ—6Φ之间。沉积物粒径趋势分析结果表明,闽江入海泥沙经梅花水道和长门水道入海后,在盐淡水混合、径流、潮流的作用下,在闽江河口形成了四个粗颗粒沉积物汇聚区,成为闽江口地区海砂资源的重要分布区;而细颗粒物质在河口羽流和潮流的作用下向偏东方向输运,形成了以黏土质粉砂为主的前三角洲。     

基于分解袋法的闽江河口芦苇和短叶茳芏枯落物的残留率和分解速率北大核心CSCD

以闽江河口鳝鱼滩的芦苇(Phragmites australis)群落、短叶茳芏(Cyperus malaccensis)群落和芦苇+短叶茳芏群落植物枯落物为研究对象,采用分解袋法,2016年2月19日～2017年2月28日期间,研究了不同群落中两种植物枯落物的残留率和分解速率。结果表明,芦苇群落和芦苇+短叶茳芏群落中的芦苇枯落物的残留率分别为35.87%和28.67%,短叶茳芏群落和芦苇+短叶茳芏群落中的短叶茳芏枯落物的残留率分别为7.00%和9.57%;短叶茳芏群落和芦苇+短叶茳芏群落中的短叶茳芏枯落物的分解速率分别为0.007 292 g/d和0.006 150g/d;芦苇+短叶茳芏群落和芦苇群落中的芦苇枯落物的分解速率分别为0.003 243 g/d和0.002 607 g/d。芦苇+短叶茳芏群落中的芦苇枯落物分解的更快;芦苇+短叶茳芏群落中的短叶茳芏枯落物分解的较慢。     

九龙江口浮游植物群体对盐度胁迫的快速适应

Mixing of freshwater and seawater creates the well-known salinity gradients along the estuaries. In order to investigate how phytoplankton respond to the acute salinity changes, we exposed natural phytoplankton assemblies from the Jiulong River Estuary to differential saline field water while continuously monitoring their photosynthetic performances under both indoor-and outdoor-growth conditions. When the natural cell assemblies from salinity 30 field water were exposed to series low saline field water(salinity 25, 17, 13 and 7.5), the effective Photosystem II quantum yield(ΔF/F_m′) decreased sharply, e.g., to one-fifth of its initials after 5 min exposure to salinity 7.5 field water, and then increased fast during the following 40 min and almost completely recovered after 320 min. During such an exposure process, non-photochemical quenching(NPQ) sharply increased from 0 to 0.85 within 5 min, and then decreased to nearly 0 within the following 70 min. When these cells re-acclimated to salinity 7.5 field water were exposed to series high saline field water(salinity 13, 17, 25 and 30), a similar response pattern was observed, with the decreased ΔF/F_m′ accompanied with increased NPQ, and followed by the recovery-induced increase in ΔF/F_m′ and decrease in NPQ. A similar response pattern as ΔF/F_m′to the acute osmotic stress was also observed in the photosynthetic carbon fixation capacity according to radiocarbon(~(14)C) incorporation. Our results indicate that estuarine phytoplankton assemblies could rapidly recover from the acute osmotic stress, implying a potential cause for their frequent blooms in coastal-estuarine waters where despite drastically varying salinity, available nutrients are abundant due to the land-derived runoffs or mixing-caused relaxations from sediments.     

我国瓯江口和珠江口凤鲚洄游模式和生境利用研究

Habitat use of the tapertail anchovy(Coilia mystus Linnaeus, 1758) from the Oujiang River Estuary and the Zhujiang(Pearl) River Estuary was studied by examining the environmental signatures of Sr and Ca in otoliths using electron probe microanalysis. Individuals from the Oujiang River had higher and varied Sr:Ca ratios(expressed as(Sr:Ca)×1 000, 3.83–13.0 average) in the otolith core regions, suggesting that they were born in brackish or sea waters, and that a freshwater habitat might not be necessary for egg hatching and larval growth.While, individuals from the Zhujiang River had lower Sr:Ca ratios(0.39–2.51 average) in the core regions,suggesting a freshwater origin. After hatching, anchovies from the Zhujiang River migrate downstream to the river estuary close to brackish water. Our results demonstrated varied habitat use for spawning during stages of early life history between the two populations, and suggested that such variations are promoting diversity of life history strategies of this species.     

福建漳江口红树林保护区浮游植物群落的季节变化研究

于2001年1月～2003年1月对福建省漳江口红树林区水体浮游植物群落的季节变化进行了研究。结果表明,漳江口红树林区浮游植物以硅藻门种类为主,优势种为长菱形藻(Nitzschia longissima)和菱形藻(Nitzschia sp.1)等,同时出现多种裸藻、绿藻和甲藻。本次调查共鉴定到浮游植物31属87种(包括变种),其中硅藻门23属75种(包括变种),蓝藻门3属3种,绿藻门1属4种,金藻门1属1种,甲藻门2属2种,裸藻门1属2种。浮游植物密度变化范围为2.78×104～1.14×106个/L,平均为3.51×105个/L,季节变化为双峰型。出现大量的底栖硅藻和淡水性藻类是该水域浮游植物的一个特点。浮游植物的组成和结构表明该水域水质较好。     

九龙江口秋茄红树林恢复对底质磷的影响

以光滩为对照,分别在白礁选取5、6、8a生秋茄(Kandelia candel)人工林以及天然秋茄林为样地,在草埔头选取20a生和44a生秋茄人工林为样地,比较分析了福建九龙江口秋茄红树林恢复对底质总磷和有效磷的影响.结果表明:白礁和草埔头秋茄人工红树林的总磷和有效磷含量随红树林恢复时间的增加而增高.白礁天然秋茄林和草埔头秋茄人工林的总磷随底质深度增加而减少,有效磷在中下层含量较高.潮位对草埔头总磷有显著影响,由外滩到内滩,其总磷含量逐渐增加.九龙江口秋茄红树林早期恢复阶段的底质总磷和有效磷缺乏,5a生秋茄人工林底质总磷和有效磷分别为0.68g/kg和2.99mg/kg.     

基于MapObjects的闽江口湿地信息系统

在动态度、马尔柯夫链等数学方法和景观生态学理论指导下,建立了闽江口湿地时空演变模型,应用组件式技术,利用MapObjects在Visual Basic平台上,进行闽江口湿地时空演变信息系统设计和开发,并应用该信息系统对闽江口湿地时空演变进行实例分析。结果表明,该系统能更高效、直观管理闽江口湿地空间信息和属性信息,以形象化的方式对湿地作全局性时空分析,使得闽江口湿地管理和保护更加科学。     

九龙江口红树植物叶片重金属元素含量及动态

本文探讨了福建九龙江口潮间带秋茄、木榄、红海榄、白骨壤和桐花树等红树植物叶片重金属元素Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ、Ｍｎ的含量及动态。结果表明，该河口红树林区表层土壤沉积物元素含量顺序为Ｍｎ〉Ｚｎ〉Ｐｂ〉Ｃｕ〉Ｃｄ；５种红树植物叶片元素含量顺序为Ｍｎ〉Ｚｎ〉Ｃｕ〉Ｐｂ〉Ｃｄ；不同物种叶片元素含量大都有明显差异；叶片对土壤元素富集系数，以Ｍｎ、Ｃｄ较高，Ｐｂ最低；随叶片从幼叶－成熟叶－黄叶的生长发育，Ｍｎ