Three new species of Anthomedusae (Hydrozoa: Hydroidomedusa) from the Guangdong coastal water, China     

张才学  黄加祺  孙省利  柯盛  杨国欢  宋之光  刘耀谦 《海洋学报(英文版)》2020,39(4):84-88

The samples of Anthomedusae were collected from the Guangdong coastal water,China.Three new species of Anthomedusae,i.e.Zhangiella condensum Huang,Zhang et Sun,sp.nov.,Hydractinia leizhouensis Huang,Zhang et Yang,sp.nov.,and Cladosarsia simplex Huang,Zhang et Ke,sp.nov.are described.All type specimens are deposited in College of Ocean and Earth Sciences,Xiamen University.  相似文献   

威海荣成桑沟湾海域海草床分布现状及其生态特征   总被引：1，自引：0，他引：1  

李政  李文涛  杨晓龙  张彦浩  张沛东 《海洋科学》2020,44(10):52-59

海草床是生物圈最高产的生态系统之一,在氮捕获、碳封存、水质净化及维持生物多样性等方面发挥关键作用。2016年8月通过对威海荣成桑沟湾海域的现场调查,发现分布总面积约为471.72 ha的海草床,种类为鳗草（Zostera marina）、红纤维虾形草（Phyllospadix iwatensis）、日本鳗草（Zostera japonica）和丛生鳗草（Zostera caespitosa）,分布面积分别为395.33 ha、37.28 ha、32.74 ha和6.37 ha。鳗草分布范围较广,平均茎枝密度817.0±27.6 shoots/m²,平均生物量646.6±41.8 g DW/m²;红纤维虾形草主要分布于桑沟湾北部养殖池和南部楮岛海域,平均茎枝密度2 649.0±29.8 shoots/m²,平均生物量2 381.3±27.3 g DW/m²;日本鳗草主要分布于桑沟湾西部八亩地海域,平均茎枝密度506.0±26.2 shoots/m²,平均生物量118.3±12.5 g DW/m²;丛生鳗草主要分布于桑沟湾南部楮岛海域,其平均密度为513.0±17.9 shoots/m²,平均生物量为479.1±28.1 g DW/m²。结合历史资料,发现桑沟湾海域海草床严重退化,分析了海草床的退化原因并提出了相应的建议和对策,以期为海草资源及滨海生境修复提供参考。  相似文献   

天津沿海赤潮发生的基本特征研究     

张琪  孙家伟  冯延竹  李希彬  王鲁宁  崔健 《海洋预报》2020,37(1):62-66

使用《天津市海洋环境状况公报》中的数据,分析天津沿海赤潮发生的特征。通过分析发现2005-2017年天津海域共发生赤潮30次,累计发生面积4 695 km2。天津沿海赤潮发生主要集中在夏季,又以8月最多,占赤潮发生总数的30%。通过赤潮优势种的分析发现近年来天津海域赤潮生物的优势种类有不断增加的趋势。同时本文从水文气象条件诱发赤潮的角度分析得出了天津沿海最易发生赤潮的天气形势,天津沿海25~27℃水温范围内赤潮发生较多,最适宜赤潮发生的风速为3、4级风,风向为东南风、西南风。  相似文献   

额河源流采金矿区不同恢复措施对矿区物种多样性和地上生物量的影响          下载免费PDF全文

许佳  祝晓瞳  苑塏烨 《干旱区地理》2019,42(3):581-589

以额河源流采金后废弃矿区为研究对象,于2011—2015年期间,通过采取不同恢复措施从被破坏矿区草地植物多样性和生物量的角度分析植被恢复效果。结果表明：（1）不同恢复措施促使各植物群落的物种数增加了5%～30%,说明采取恢复措施使得矿区生态环境得到了一定程度的恢复。（2）综合植被群落结构、盖度和地上生物量、物种多样性指数分析,措施A5（推平+圈羊）、A4（推平+补水）、A3（推平+覆土+黑加仑）较其他措施恢复效果更为显著。（3）通过对各样地植被丰富度指数（R）、Shannon Wiener指数(H′)、Simpson指数（D）、Pielou (Jsw)指数与地上生物量分别进行回归分析,发现指数曲线拟合关系最好。表明物种多样性与地上生物量均存在较显著的正相关关系(P <0.05)。本研究可为类似矿区的植被恢复与重建提供参考和借鉴。  相似文献   

基于两种无人机航拍影像的林窗和林冠提取分析     

王悦  练琚愉  张昭臣  胡健波  杨骥  李勇  叶万辉 《热带地理》2019,39(4):553-561

森林冠层和林窗的结构及其时空变化是理解森林生态系统格局、动态变化过程的重要基础。在当前生物多样性监测倍受关注的契机下,如何以合适的手段准确描述林窗面积、分布等特征,并与森林固定样地监测数据有效地结合,更好地回答群落构建的理论问题,使森林群落物种多样性维持机制得到更全面的认识,是目前亟待解决的问题。以鼎湖山南亚热带常绿阔叶林20hm2固定监测样地为研究对象,基于不同遥感影像提取方法对其林窗和林冠表层数据进行提取分析。结果表明:基于监督分类的提取方法适合RGB波段航片林窗的提取,在林窗分类中,应首先确定林窗高度、边界木与最小面积,不同分类方法差异主要表现在林冠分类中,林窗分类生产者精度和用户精度表现都较为一致。无人机航拍识别率受地形因素影响较大,在地形复杂林地应按坡度分区域进行飞行以降低误差。相对于地面调查,MD4-1000无人机航片的林窗识别率为98.7%;大疆Phantom4无人机航片的林窗识别率为72.3%,影像后期处理数据量小,同样适用于森林林窗定量研究,符合生态学、林业等从业人员对大型样地林窗长期监测的要求。无人机航拍南亚热带森林物种识别难度较大,基于MD4-1000无人机搭载的高分辨率相机,在地势平缓区域优选的4 hm2样地中可识别林冠表层物种数17种,共2 706个个体。搭载高分辨率无人机在降低飞行高度的基础上可进行部分物种识别。应用无人机近地面遥感对森林固定样地进行林冠监测,可为后期群落构建研究提供数据基础,有望从新的研究角度探讨森林群落物种多样性维持机制。  相似文献   

珠江口枯水期和丰水期中小型浮游动物群落动态          下载免费PDF全文

黄彬彬  郑淑娴  田丰歌 《应用海洋学学报》2019,38(1):43-52

根据珠江口枯水期(2013年11月)和丰水期(2014年8月) 24个站位调查资料,对中小型浮游动物种类组成、丰度分布、群落结构及其主要影响因子进行了研究.结果表明,枯水期和丰水期分别鉴定浮游动物成体91种和70种,以桡足类最为丰富.浮游动物种类从河口上游向外围逐渐增加.浮游动物丰度时空分布差异显著,丰水期平均值高达11 619. 78 ind/m~3,显著高于枯水期的1 707. 13 ind/m~3.桡足类在珠江口中小型浮游动物中占绝对优势,枯水期和丰水期分别占总丰度的80. 3%和93. 0%,对浮游动物的丰度分布起关键作用.强额孔雀哲水蚤(Parvocalanus crassirostris)、中华异水蚤(Acartiella sinensis)和刺尾纺锤水蚤(Acartia spinicauda)在两个水期均为主要优势种,小拟哲水蚤(Paracalanus parvus)和厦门矮隆哲水蚤(Bestiolina amoyensis)则分别在枯水期和丰水期具有较高的优势度.聚类分析的结果显示,枯水期和丰水期该水域浮游动物均可划分为3个群落.相关性分析表明,珠江口中小型浮游动物群落结构受多个环境因子的影响,但盐度是其中最为关键的非生物因子.  相似文献   

A Raman investigation on the boron form occurring in salt lake brine during evaporation     

彭姣玉  陈婧  王兴鹏  董亚萍  李武 《盐湖研究》2019,27(1)

Boron resources are abundant in Da Qaidam salt lake of Qaidamu Basin. It has been given great attention for the polyborate species present in brine. In this study, the Raman spectroscopy was applied to investigate the existing-form of boron in brine during evaporation. The prepared solutions of MgO·2B2O3-H2O, MgO·2B2O3-MgCl2 -H2O, and MgO·2B2O3-MgSO4-H2O was also evaporated and recorded to study the influence of boron concentration, pH, and electrolytes on the borate speciation in brine. The mononborates of B(OH)3 and B(OH)4- were found to be the only forms present in the original salt lake brine. Brine evaporation promotes the formation of polyborate anions B3O3(OH)4-, B5O6(OH)4-, and B6O7(OH)62- and also disappearance of the B(OH)4- ion in brine with boron concentration of more than 11 g/L in B2O3. The pentaborate ion of B5O6(OH)4- was sensitive to the solution pH and found to be appeared under the pH value of 8.0. While the hexaborate ion of B6O7(OH)62- was observed more dependent on the electrolyte of magnesium chloride due to its special properties, such as promoting boron accumulation, lowering solution pH, and also the strong af?nity for water molecules, which is beneficial to the polymerization of borate ions in brine. The interaction mechanisms among polyborate anions during evaporation had also been proposed.  相似文献   

Effects of current climate,paleo-climate,and habitat heterogeneity in determining biogeographical patterns of evergreen broad-leaved woody plants in China   总被引：1，自引：1，他引：0  

Xu  Yue  Shen  Zehao  Ying  Lingxiao  Zang  Runguo  Jiang  Youxu 《地理学报(英文版)》2019,29(7):1142-1158

Journal of Geographical Sciences - Understanding biogeographic patterns and the mechanisms underlying them has been a main issue in macroecology and biogeography, and has implications for...  相似文献   

Species Abundance Distribution Patterns of a Toona ciliata Community in Xingdoushan Nature Reserve     

WANG Yang  ZHU Shengjie  LI Jie  HE Xiuling  JIANG Xiongbo  ZHANG Min 《资源与生态学报(英文版)》2019,10(5):494-503

With the goal of model fitting species abundance distribution patterns of the tree, shrub and herb layers of the natural Toona ciliata community in Xingdoushan Nature Reserve, Enshi Autonomous Prefecture, Hubei Province, we used the data collected from the field survey and employed different ecological niche models. The models tested were the broken stick model (BSM), the overlapping niche model (ONM) and the niche preemption model (NPM), as well as three statistic models, the log-series distribution model (LSD), the log-normal distribution model (LND) and the Weibull distribution model (WDM). To determine the fitted model most suitable to each layer, the fitting effects were judged by criteria of the lowest value of Akaike Information Criterion (AIC), Chi-square and the K-S values with no significant difference (P>0.05) between the theoretical predictions and observed species abundance distribution values. The result showed: (1) The fitting suitability and goodness of fit of the tree, shrub and herb layers by using the three ecological niche models were ranked as: NPM>BSM>ONM. Of the three statistical models, by accepting the fitting results of the three layers, WDM was the best fitting model, followed by LND. By rejecting the fitting tests of the herb layer, LSD had the worst fitting effect. The goodness of the statistical models was ranked as: WDM>LND>LSD. In general, the statistical models had better fitting results than the ecological models. (2) T. ciliata was the dominant species of the tree layer. The species richness and diversity of the herb layer were much higher than those of either the tree layer or the shrub layer. The species richness and diversity of the shrub layer were slightly higher than those of the tree layer. The community evenness accorded to the following order: herb>shrub>tree. Considering the fitting results of the different layers, different ecological niche models or statistical models with optimal goodness of fit and ecological significance can be given priority to in studying the species abundance distribution patterns of T. ciliata communities.  相似文献   

利用稳定同位素(15N)示踪技术研究浮游藻类氮素吸收速率特征     

韩菲尔  赵中华  李大鹏  张路 《海洋与湖沼》2019,50(4):811-821

浮游藻类对溶解态氮的吸收同化是湖泊氮生物循环和水体富营养化发生机制探讨的关键环节。本文通过~(15)N稳定同位素添加实验以铜绿微囊藻(Microcystis aeruginosa)、海链藻(Thalassiosira sp.)、卡德藻(Tetraselmis sp.)、剧毒卡尔藻(Karlodinium veneficum)以及盐水隐藻(Rhodomonas salina)为研究对象,从浮游藻类氮素吸收时间、营养盐基质以及藻种差异三个方面研究五种藻类对铵氮(NH_4~+-N)、硝氮(NO_3~--N)、尿素氮(Urea-N)三种形态氮的吸收特征。研究发现:(1)浮游藻类对三种形态氮的吸收均在1h时吸收速率最高,其氮素吸收过程为快速吸收。(2)浮游藻类优先吸收还原态氮,其中NH_4~+-N吸收速率最高,当培养周期为1d和4d时浮游藻类对NH_4~+-N吸收速率的均值分别为4.05和4.15μmol/(L·h);浮游藻类对Urea-N吸收相对偏好系数为25.18—713.42,表现出对小分子溶解态有机氮的特定偏好性。(3)不同藻种对氮素吸收具有不同特征,其中,剧毒卡尔藻对三种形态氮的吸收速率均为最高,而铜绿微囊藻的吸收速率均为最低;不同藻种不同培养时间氮素吸收速率差异与浮游藻类生长周期等特性有关。不同浮游藻类对不同形态氮素表现出吸收特异性,对水体氮负荷和浮游藻类水华优势种形成将产生重要影响。  相似文献