Environmental drivers of phytoplankton crops and taxonomic composition in northeastern Antarctic Pen

来源 :海洋学报(英文版) | 被引量 : 0次 | 上传用户:bittermonkey
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The ecosystem of the sea region adjacent to the Antarctic Peninsula is undergoing remarkable physical and biological changes, in the context of global warming. However, understanding of the dynamics of phytoplankton taxonomic composition in this marginal ice zone remains unclear. In this study, seawater samples collected from 36 stations in the northeastern Antarctic Peninsula were analyzed for nutrients and phytoplankton pigments. Combining with CHEMTAX analysis, remote sensing data, and physicochemical measurements, we investigated the relationships between phytoplankton crops, taxonomic composition, and marine environmental drivers. Integrated chlorophyll a (Chl a) concentrations (200 m) varied from 8.9 mg/m2 to 64.2 mg/m2, with an average of (23.2±12.0) mg/m2 and higher phytoplankton biomass concentrated in the coastal region of South Orkney Island and South Shetland Island. Diatoms were the dominant functional group (63%±21%). Higher proportions of diatoms were associated with higher Chl a (r=0.40, p<0.01), stable water columns (r=0.20, p<0.01), higher Si/P ratios (r=0.34, p<0.01), higher photosynthetically active radiation intensity (r=0.64, p<0.01), and higher sea ice melt water contributions (MWC, r=0.20, p<0.01). Conversely, Phaeocystis antarctica contributed a smaller overall proportion (31%±18%) and was more concentrated in the offshore water masses (e.g., Philip Ridge and South Scotia Ridge) with lower light levels (r=?0.58, p<0.01), deeper mixed layer depths (r=0.17, p0.35, p<0.01), and lower MWC (r=?0.20, p<0.01). In comparison, the total contribution from green flagellates (4%±5%), cryptophyta (1%±3%), dinoflagellates (1%±4%), and cyanobacteria (1% ± 5%) was only 6%. In offshore regions with well-mixed water, less varied taxonomic composition and lower crops with a higher proportion of nanophytoplankton were observed. In contrast, significantly decreasing crops below the mixed layer depth was observed in water columns with strong stratification, where the dominant phytoplankter changed from diatoms to P. antarctica. These findings have important implications for better understanding the future dynamics of marine ecosystems in the sea area adjacent to the Antarctic Peninsula.
其他文献
基于自适应增强算法(AdaBoost)结合极限学习机(ELM),通过迭代、调整、优化ELM分类器之间的权值,从而构建了具有强鲁棒性、高精度的ELM-AdaBoost强分类器,增强了现有的ELM分类器的稳定性.以珠江口海区侧扫声呐图像为实验数据,对礁石、砂、泥3类典型底质进行分类识别,该方法的平均分类精度超过90%,优于单一ELM分类器的平均分类精度85.95%,也优于LVQ、BP等传统分类器,且在分类所耗时间上也远少于传统分类器.实验结果表明,本文构建的ELM-Ada-Boost方法可有效应用于海底声学底
人才是区域竞争的关键.为打造区域科技创新中心,杭州市着力围绕“一廊三城”(城西科创大走廊、未来科技城、青山湖科技城、紫金港科技城),不断完善人才支撑体系,以“打造全球人才蓄水池、建设三大创新高地、创建综合性国家科学中心”为目标,大力实施人才优先发展战略,培养造就一大批高层次科技创新人才,推动区域科技创新中心建设,实现创新驱动高质量发展.
The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing. This study selected sea surface temperature (SST) from two commonly used sources, the N
专精特新“小巨人”是指专业化、精细化、特色化、创新能力突出的中小企业.2021年7月30日,中央政治局会议提出,开展强链补链专项行动,发展专精特新中小企业.国家工信部自2018年启动培育工作以来,目前已培育三批共计4762家,其中浙江470家、杭州53家.
为了提高量子安全传输效率,采用n粒子Greenberger-Horne-Zeilinger(GHZ)态的特性,对其与单光子混合的量子安全直接通信进行了研究,设计了通信的执行过程,讨论了通信的传输效率、量子比特利用率和编码容量,并对其安全性进行了理论分析.结果表明,该方案可以将信息的编码容量提升至(n+1)bit,将传输效率提升至200%.该协议能够抵御截获重发和测量重发攻击、特洛伊木马攻击和拒绝服务攻击以及辅助粒子攻击和纠缠攻击.
为了实现电介质超表面的聚焦功能和对光场相位的调控,采用几何相位调制原理设计微元结构及空间分布,以SiO2为基底、亚波长TiO2椭圆柱的六边形晶胞为基本结构,设计了一种相位突变呈抛物线梯度分布的聚焦超表面,适用于480nm~580nm波段.基于此结构进行了理论分析和实验验证,发现该结构对线偏振光聚焦,其归一化后的半峰全宽约为428nm,而对矢量光聚焦约为258nm,获得了更出色的聚焦效果.研究了3阶和4阶Ince-Gaussian矢量光场通过该超表面后的聚焦特性,得到了聚焦场能保持入射矢量光场的基本空间结构
数字经济正在成为重组全球要素资源、重塑全球经济结构、改变全球竞争格局的关键力量.杭州自实施数字经济一号工程以来,数字经济快速发展,已成为驱动经济增长的核心关键力量.
非局域色散消除是量子纠缠光源的非经典效应之一,在量子信息科学中有着重要的应用.详细介绍了非局域色散消除的概念、研究意义以及近几年国内外的发展状况.对频率纠缠光源的非局域色散消除、Franson干涉仪中的非局域色散消除、Hong-Ou-Mandel干涉仪中的局域色散消除等3种情况的研究进展进行了对比分析.在此基础上,对量子色散消除的研究前景进行了展望.
随着人口老龄化进程的加快,生物医药产业越来越受到广泛关注.2020年9月,习近平总书记在科学家座谈会上发表重要讲话,在“三个面向”的基础上提出了“面向人民生命健康”.rn近年来,浙江省出台了《浙江省生物经济发展行动计划(2019-2022年)》《关于加快推进医药产业创新发展的实施意见》等文件,加速构建具有世界影响力的生物经济产业集群,在创新强省中建立生命健康科创高地.
为了降低激光多普勒振动信号中噪声产生的影响,采用基于改进小波去噪算法的激光多普勒振动信号处理方法,将尺度引入阈值函数,确立新的评价指标用于选择最优分解层数,从而来改进小波阈值去噪算法,并利用改进的算法处理振动信号,进行了仿真分析和实验验证,取得了处理前后的振动数据.结果表明,改进算法处理仿真信号的信噪比比原有算法提升19.4%;实验测得音叉振动频率为515Hz,与实际音叉频率基本吻合.这一结果对降低激光多普勒振动信号中噪声的影响、获取振动状态是有帮助的.