Morphological and molecular diagnoses of Polydora brevipalpa Zachs,1933(Annelida: Spionidae) from the shellfish along the coast of China

Shell-boring species Polydora brevipalpa Zachs, 1933 is redescribed based on morphological observations and molecular approach for future unambiguous identification. Genetic distance analyses showed that the interspecific polydorid variation(16.7%–25.6%) was at least 15 times higher than the intraspecific one(0.2%–0.9%) based on the cytochrome c oxidase subunit I(CO1) gene sequences of polydorids. However, 18 S rDNA variation pattern demonstrated a rather narrow barcoding gap, with the interspecific polydorid variation(0.5%–5.6%) being very close to the intraspecific one(0.0%–0.4%). As such, the CO1 gene exhibited better DNA barcode for identification of polydorids than the 18 S rDNA gene because of the su ciently large barcoding gaps. Analysis of molecular variance results based on CO1 gene sequences showed that most variations in sequences(97.79%) lay within groups of adult worms and egg capsules rather than between them. This indicated that egg capsules from Crassostrea gigas(Thunberg,1793) in Ningbo and Nantong were related to the adult worms from Patinopecten yessoensis(Jay, 1857) in Dalian, and both of them belonged to P. brevipalpa. This result was further supported by parsimony network analysis, which showed that egg capsules collected from dif ferent localities and adult worms shared a single haplotype. This study was the first to report both P. brevipalpa infestation on C. gigas and to utilise the known CO1 sequences of the adult polydorids to validate morphologically unidentified egg capsules or early larvae. P. brevipalpa was most possibly brought to Chinese waters through transportation of Pa. yessoensis brood stock from Japan.     

基于AnnAGNPS模型的山美水库流域非点源氮控制研究

探索研究流域非点源氮污染控制的有效措施,对于治理改善水环境恶化具有重要的现实和长远意义。以山美水库流域为研究区域,建立AnnAGNPS氮污染模型,通过情景模拟技术分别模拟了河岸缓冲带、适量施肥、免耕、少耕、梯田和退耕还林等最佳管理措施的非点源氮污染削减效率。结果表明:(1)梯田与退耕还林对氮的削减率较高,均高于15%;免耕较低,为13%;少耕、合理施肥、河岸缓冲带削减效果有限,低于10%。(2)河岸缓冲带、少耕、免耕、梯田等措施的总氮削减率在不同月份的变化趋势与泥沙削减变化趋势一致,在7月和8月有较高的削减率;合理施肥与退耕还林的总氮削减率则与流域施肥状况相关性更高,在2—4月份有较高的削减率,因此山美水库流域水环境改善应结合非点源氮污染治理和流域水土流失治理。     

Assessment of Desert Ecological Assets and Countermeasures for Ecological Compensation

Can deserts be transformed into resources, into assets, and further into cash? It is necessary to scientifically assess desert ecological assets and incorporate them into the national economic accounting system and the current evaluation system for socio-economic development. This study will provide a scientific basis and robust data for establishing a target system that is compatible with both ecological civilization and an associated reward and punishment mechanism, as well as for designing and implementing effective compensation policies for desert ecosystems. This paper first defines desert ecological assets, and then develops a framework for assessing them based on the evaluation of desert ecological resources and desert ecosystem services. This framework paves the foundation for quantitatively assessing desert ecological assets and preparing balance sheets of desert ecological assets. Finally, this paper analyzes current policies relating to desert ecological compensation, discusses how to design compensation policies based on assessment of desert ecological assets, and puts forward suggestions for improving current policies.     

外来与乡土红树种间竞争十五年的群落现状与发展趋势

为了探究经过15年种间竞争后的外来无瓣海桑(Sonneratia apetala)与乡土红树植物秋茄(Kandelia obovata)的群落现状与发展趋势,采用样方法对福建省厦门市同安湾典型红树林群落特征开展实地研究。结果表明:(1)无瓣海桑是无瓣海桑群落中的优势种,而秋茄仅在该群落北侧与无瓣海桑少量混交,秋茄+无瓣海桑群落为种植秋茄和无瓣海桑的茂密混交林;(2)调查幼苗天然更新情况中发现,在两个群落中秋茄均有幼苗自然生长,但均未发现无瓣海桑幼苗;(3)生长状况的调查发现,无瓣海桑长势较秋茄差,其倒伏数量和倒伏程度明显比秋茄严重;(4)无瓣海桑在秋茄+无瓣海桑群落中的生长状况优于在无瓣海桑群落,倒伏程度较轻。综上可见,无瓣海桑在福建省厦门市该研究样地及其周边更新成林和扩散困难,未有入侵秋茄群落的优势;无瓣海桑在风浪环境下,较秋茄更易出现倒伏和枯死等不可逆生长现象;红树林种植过程中采用"外来种+乡土种"的模式,可提高整个林分的抗风浪能力,但需注意种植布局规格的合理性,可避免外来速生快长种与乡土种紧邻混交产生较大的种间竞争,减小对乡土种生长的影响。     

日本“3·11”海啸引起的乐清湾共振研究

本文基于TELEMAC-2D模型建立太平洋区域海啸传播模型,模拟2011年日本“3·11”海啸事件下海啸波的传播。使用实测数据对该模型进行验证,在模型验证良好的基础上分析日本“3·11”海啸事件对乐清湾的影响。通过频谱分析得到“3·11”海啸激发的乐清湾内240、180和103 min这3个主导模态的幅值及其相位。通过白噪声实验对乐清湾的固有共振特征进行估算,进一步支持了乐清湾在上述3个模态发生共振这一结论。白噪声实验还表明,海啸等海洋灾害发生时会在乐清湾湾顶及湾口处产生较大的增水,该结论对乐清湾内海洋灾害风险防范具有指导意义。     

胶州湾潮余流和物质输送之间的关系

基于MIKE21的HD模型,通过模拟得到胶州湾的潮流场,胶州湾在涨急时最大流速1.04m/s,落急时最大流速约为0.96m/s。胶州湾余流总体较小,平均为0.03m/s左右。并在湾内不同位置释放自由粒子,以MIKE21的Particle tracking模型计算出其在潮流作用下的运移轨迹,结果表明粒子大多数运移到湾内近岸区域,少部分在湾口区域附近;在潮流场基础上计算了欧拉余流场,并和粒子运移结果进行对比,表明欧拉余流场在区域流向比较一致时可以表示粒子运动的趋势,为物质迁移、控制污染等方面提供了一定的参考借鉴意义。     

中国东海陆架海域柱状沉积物对磷的吸附行为

通过研究磷在海洋柱状沉积物上的吸附动力学曲线和吸附等温线,并结合沉积物表面电荷性质以及磷形态分析,考察了我国东部陆架海域沉积物对磷的吸附特征。结果表明,所研究海域沉积物对磷的吸附过程明显分为快慢两段,48h后吸附可达到平衡;吸附后的磷主要为可交换态磷,吸附过程以物理作用为主;吸附等温线可用Langmuir交叉型模式描述,在磷初始浓度较低时,沉积物对磷存在解吸现象;沉积物对磷吸附参数的垂直分布较为复杂,受自身性质影响较大;盐度增大,沉积物对磷的吸附能力呈下降趋势。     

录井校正新方法在东海盆地西湖凹陷的应用

录井检测受井场环境影响较大,主要包括钻井环境与检测环境,钻井环境包括井径、钻时、钻井液排量、是否取心等,检测环境主要是井场自然环境与检测器内部环境。一般情况下检测器内部环境基本一致,而井场自然环境在一定时间内变化不大,故而钻井环境对录井检测的影响较大,钻井环境校正是进行录井解释前的重要工作。常规Tg(全烃含量)校正方法在取心、低异常、多互层等层段使用效果较差,经过分析,将校正方法在取心、钻时、排量、基值方面进行优化,实践验证,新校正方法效果较好,适应了西湖凹陷的地质研究需求。     

新一代电子航海图面图案结构的SVG表达

针对电子航海图现行符号标准S-52难以利用和扩展的问题,分析研究了S-52标准中面图案的结构表达方法,提出了两种新方案:一是基于SVG的电子航海图面图案结构表达方法,二是基于SVG与XML参数的电子航海图面图案结构表达方法。最后,按照第二种方案,实现了S-52面图案的重构和转换,构建了完整的电子航海图面图案符号集合。