3种海岛植被修复典型植物耐盐能力研究

以3种海岛植被修复典型植物木麻黄(Casuarina equisetifolia)、夹竹桃(Nerium indicum)和台湾相思(Acacia confusa)为实验材料,通过对培养基质及植株叶片施加不同浓度的盐溶液,研究不同植物的耐盐能力,筛选耐盐树种.主要结论如下:(1)根据植株生长状况,木麻黄植株的根、叶均可耐受质量浓度3.0%的盐胁迫;夹竹桃植株可耐质量浓度1.0%以下的根系盐胁迫和质量浓度3.0%以下的叶片盐胁迫;台湾相思植株可耐浓度质量2.0%以下的根系盐胁迫和质量浓度0.6%以下的叶片盐胁迫;(2)综合研究结果显示,3种植株耐盐能力为木麻黄夹竹桃台湾相思;(3)植物的生长状态、成活率和株高增长率指标可以很好的指示植株受盐害程度及耐盐能力,可结合赋值法对区域植被耐盐能力进行简单快速的调查;(4)在土壤含盐量较高和受海洋飞沫影响较大的滨海地带开展植被修复时,推荐木麻黄为优先树种;但在土壤含盐量较低的干旱地带,推荐夹竹桃作为先锋品种.     

基于光合特性的海岛植被修复适生植物的筛选

海岛植被破坏严重,而适生物种少的问题已严重影响到海岛植被修复研究工作.本研究通过测定海坛岛和大屿共30种植物的夏季日间光合特性、水分利用效率和比叶面积,为海岛水土流失区生态修复过程中适生植物的筛选提供重要的理论依据.研究结果表明,在海坛岛和大屿的共有种中,仅台湾相思(Acacia confusa)和海桐(Pittosp...     

无居民海岛植被恢复过程中物种多样性及土壤特征初步研究

2016年4月对厦门无居民海岛猴屿开展了植被和土壤调查,采用全岛调查的方法查清全岛植物种类及生长状况,采用样方调查的方法分析比较人工恢复林和次生林物种多样性和土壤肥力特征,以期为无居民海岛生态修复提供借鉴.结果表明,全岛共有乔木5科5属6种,灌木有10科12属13种,草本植物有21科39属40种.由于被海包围、面积狭小、地形简单,物种传播速度慢,猴屿生物多样性较低,猴屿人工恢复林物种多样性与次生林差异不显著.人工恢复林土壤肥力显著低于次生林,植物生长及其产生的凋落物可以促进土壤肥力的改善.海岛普遍风大、缺水,植被恢复应选用适应海岛环境能力强的物种.猴屿植被破坏导致生态位缺失,进而造成马缨丹生物入侵,影响海岛生态系统稳定性.     

平潭周边典型海岛临海坡地植被分布特征与修复应用

海岛独特的自然环境制约了植物的生长,但同时也自然筛选了一批适应能力较强的海岛植物种类。文章采用线路调查和典型样地调查相结合的方法,对平潭岛群中的塘屿、东庠岛、大练岛等海岛临海荒坡山地植被进行实地调查。通过了解平潭周边典型海岛的植被种类、分布及群落结构,分析平潭典型海岛的植被特征,指出风、干旱、盐害及土壤等环境因子是影响平潭周边典型海岛植被生长的制约因素,并针对这几个制约因素,结合调查结果从植物品种筛选、植被配置、修复技术等方面提出困难立地条件的海岛植被修复对策,为相近区位的植被生态修复提供借鉴。     

平潭大屿岛上台湾相思长势的时空差异性

为了探讨台湾相思群落生长发育与气候特征的关系,选用11个位于大屿靠海一侧不同地点的台湾相思群落研究对象。通过2016年4—12月对台湾相思标记枝条的生长状况进行长期监测。观测结果表明:11个样点受盐害叶片占比为1.16%~51.48%,受虫害叶片占比为30.27%~59.78%。植株大多受到盐害与虫害的干扰,花数量和花蕾数量处于一个较低的水平。由植物生长状况与气候特征的相关性结果可知,风向和风力随月份变化而变化,12月风力最高达5.93m/s。月份和风向与受盐害叶片占比、受虫害叶片占比均呈现极显著相关性。在开展海岛植被生态修复时,需要注重冬季养护、病虫害防治和筛选抗风、耐盐雾的海岛适生物种。     

盐胁迫下夹竹桃生理光合特性及生态修复应用

海洋盐分主要通过地下水入侵、浪花飞溅、盐雾等方式对滨海植物的根、茎和叶产生影响。采用长势良好2年生夹竹桃（Nerium indicum）,分别设置对照0%、0.3%、0.6%、1%、2%、3%多个浓度梯度,开展根系和叶片耐盐实验。盐胁迫处理13周后正常浇水4周。在盐胁迫末期及正常浇水后测定叶片净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）、水分利用率（WUE）等光合指标;同时测定细胞膜透性、叶片饱和水分亏缺（WSD）等理化指标。结果表明：根系盐胁迫和叶片盐胁迫均会影响夹竹桃植株形态和生长,根系盐胁迫≥1.0%时,夹竹桃植株生长状态向着小于2的趋势发生不可逆下降;叶片盐胁迫≤3.0%时,夹竹桃生长状态普遍大于2。根系盐胁迫极显著降低夹竹桃叶片Pn、Tr和Gs;叶片盐胁迫对夹竹桃植株的Pn和WUE影响极显著,对Tr和Gs无显著影响。夹竹桃Tr与Gs之间极显著相关;高浓度根系盐胁迫下,气孔因素对夹竹桃光合影响较为显著。叶片盐胁迫下,夹竹桃细胞膜透性和WSD变化不显著,高浓度根系盐胁迫下,夹竹桃细胞膜透性和WSD发生不可逆改变;这与生长状态和光合特性的结果可以很好对应,说明膜系统受损反过来影响夹竹桃生长和光合作用。总体上,夹竹桃可耐受3.0%以下的叶片盐胁迫和1.0%以下的根系盐胁迫。将根系和叶片耐盐特性分别研究,可以更好地为夹竹桃在滨海生态和植被修复应用中提供理论指导。     

厦门大兔屿种子植物区系分析及其植被修复对策研究

通过样方法和样线法对大兔屿进行植物资源调查,其主要的植被类型是亚热带常绿阔叶林、灌草丛。有维管植物69科,139属,152种。蕨类3科,3属,3种;裸子植物3科,3属,3种;被子植物63科,133属,146种。乔木20科,27属,30种;灌木31科,44属,46种,草本和藤本30科,68属,74种。其中,原生植物125种,外来植物27种,入侵植物10种,无珍稀濒危植物。植被群落的植物区系组成中,属的分析表明,大兔屿植物以热带、亚热带成分为主。种子植物属划分为12个分布区类型及其变型,其中成分最多的是泛热带分布及其变型,为区系总数的35.29%。群落以高位芽植物占主要优势,为46.71%。人工栽培的台湾相思林、马尾松林及木麻黄林总的覆盖率却高达80%。最后针对海岛特色景观的营造,对大兔屿植物资源的保护和利用提出相关的建议。     

样线法在北方基岩性海岛植被调查中的应用效果评价 ——以北长山岛为例

植被是海岛生态系统的重要组成部分。由于海岛陆地环境与大陆的差异性,现有的陆域植被调查方法不能完全适用于海岛植被。亟须结合现有成熟的陆地植被调查方法,选取不同类型的海岛,对调查方法中的关键环节进行实地测试,积累数据进行统计分析,以得到适用于海岛特殊地理环境海岛植被调查技术方法。文章针对植被调查中的样线法,以北长山岛两种不同面积的调查区域为例,对比分析不同样线设置方法,明确在该岛屿何种坡向、坡位,何种类型植物群落中设置样线,以及设置多长的样线才能够较为完整地代表该调查区域的植物物种丰富度,同时降低大量的调查时间,最终确定最优的海岛样线设置原则,为海岛植被群落调查中样线的有效选择提供科学依据。     

SPOT、QuickBird卫星遥感数据提取东沙岛植被信息的比较

基于植被的光谱特征,利用监督分类、植被指数(NDV I)和目视解译等方法,分别用SPOT-5、Q u ickB ird高分辨率卫星遥感影像对东沙岛植被信息进行提取,并作了比对分析。研究结果表明:利用高分辨率遥感图像对东沙岛等小型岛屿的植被信息提取是可行的;SPOT-5多光谱数据具备了提取小型海岛植被信息、掌握其植被覆盖状况的能力;与SPOT-5多光谱数据相比,Q u ickB ird多光谱数据在植被精细分类信息的提取方面更具优势。     

上海大金山岛植被资源状况及保护对策

大金山岛是上海海域存留天然植被较完整的海岛,对其现状进行调查和分析有助于制定具有针对性的海岛植被保护策略。文章基于21个样地的调查,将大金山岛植被划分为常绿阔叶林、常绿落叶阔叶混交林、落叶阔叶林、落叶灌丛和草丛5个植被类型14个群落类型。地带性森林群落径级结构和物种多样性特征分析表明,大金山岛森林群落结构相对稳定、物种多样性较高。为进一步完善大金山岛的植被保护措施,需加强植被分类与制图、量化典型植物种群大小和分布特征、跟踪管理大径材树木生长和健康状况、开展植被和动物综合调查以及植被动态长期监测的研究和管理。     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.     

A Tidal Flow Model for the Gulf of Kachchh, India

A vertically integrated model has been used to study the tidal circulation and currents in the Gulf of Kachchh along the west coast of India. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve the basic hydrodynamic equations on a staggered grid. The model is forced by prescribing the tides along the open boundary of the model domain. The flow is simulated both with and without the presence of the proposed tidal barrage across the Hansthal Creek in the Gulf of Kachchh. The results show a considerable change in the behavior of the tidal flow in the presence of the barrage.     

利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测

<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is     

离子交换—原子吸收光谱法测定海水中痕量铜、铅、锌、镉、铁、锰

本文介绍了用国产D401型螯合树脂分离富集海水中铜、铅、锌、镉、铁、锰等痕量元素,并用原子吸收光谱仪测定其含量的方法。讨论了各元素的分离条件选择及干扰元素的影响,并与溶剂萃取法的结果作了比较。各元素检测的定量下限为:铜0.5μg/L、铅0.1μg/L、锌1.0μg/L、镉0.01μg/L、铁2.0μg/L、锰2.0μg/L。方法精密度在4—8％之间,回收率为90—102％。     

Biogeochemistry of Mangrove Soil Organic Matter: a Comparison BetweenRhizophoraandAvicenniaSoils in South-eastern Brazil

Soil core samples fromRhizophora mangleL. andAvicennia schauerianaStapf & Leech forests from south-eastern Brazil were analysed for their total organic matter content and their sugars, amino acid and amino sugars composition. Organic carbon and nitrogen contents were higher inAvicenniathan inRhizophorasoils. The contribution of sugars and amino acids to the total organic carbon pool was constant with depth inRhizophorasoils whereas inAvicenniasoils it increased. Spectral distribution of sugars and amino acids showed a dominance of Ca-affine monomers, particularly acidic amino acids, and the sugar arabinose. Biogeochemical indicators derived from ratios of individual sugar and amino acid monomers confirm previous studies which showed that organic matter in both soils is mainly of mangrove origin. The results further suggest accumulation of organic matter inRhizophorasoils and a continuing degradation of organic matter inAvicenniasoils. The latter may thus release more nutrients to adjacent ecosystems thanRhizophorasoils.     

A review of orange roughy Hoplostethus atlanticus fisheries,estimation methods,biology and stock structure

Orange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at 22 – 40 years), and to have exceptionally low natural mortality (M = 0.045–0.064 year^?1) and slow growth rates (K = 0.055–0.070 year^?1). In addition, they spawn large eggs and have low fecundity. These factors combine to make orange roughy highly susceptible to overfishing; most stocks are below 30% of pristine levels. Assessments are obtained from indices of catch rate and trawl, acoustic and egg surveys. Acoustic estimates are the most direct, but are confounded by the species' low target strength (?50 to ?53 dB)–attributable to the wax-filled swim bladder. Extracellular wax esters are stored in abundance and comprise mostly mono-unsaturated fatty acids, with low concentrations of the ω-3 fatty acid family. This unusual composition (resultant from the species' diet) ensures neutral buoyancy. Stock separation has been inferred mainly from biological studies, but genetic studies have also found differences among stocks within New Zealand and Australia. Deep-water habitat may be damaged by trawling operations and may take many years to recover, so in some quarters there is a call for a portion of suitable habitat to be set aside for preservation. Although Namibian orange roughy are shallower, smaller and younger than those in other stocks, the Namibian fishery sustained high catches for only a few years before quotas were reduced, from 12 000 to 1 875 tons. Three management lessons are suggested for developing orange roughy fisheries based on the Namibian experience: (1) imposition of catch limits during exploratory fishing; (2) starting the acoustic surveys earlier in the fishery, if possible; (3) greater reliance on trends in catch rate until a survey series has been established.