南麂岛岩礁潮间带软体动物种类数量变化及其演替

为揭示南麂岛岩礁潮间带软体动物种类组成与数量分布及其演替状况,于2013年11月,2014年2月、5月、8月,共4次对南麂岛的潮间带7个断面进行了定量和定性调查,并对软体动物的种类、数量和优势种变化及物种多样性进行了研究。结果显示,共鉴定出软体动物种类63种,隶属于3纲113目34科52属,其平均栖息密度和生物量为506.5个/m2和801.54 g/m2;条纹隔贻贝(Septifer virgatus)是4个季节共有的且优势度最大的优势种;软体动物Shannon-Wiener多样性指数(H')平均值为冬季(1.73)春季(1.69)夏季(1.58)秋季(1.40);与历史资料对比发现,其物种数及生物量有一定程度的减少。研究表明,南麂岛岩礁潮间带的软体动物发育较好,栖息密度和生物量远高于邻近的其他岛屿,但与此前调查结果相比却有所降低。     

Capricious bioinvasions versus uncoordinated management strategies: how the most unlikely invaders can prosper under the current UK legislation framework

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湘江流域岳麓山周边地区地表水体水化学特征及灌溉适宜性

[目的] 对湘江流域岳麓山地区地表水体进行水化学特征分析及灌溉适宜性评价,为该地区的生态环境保护及水资源综合管理的科学决策提供理论支持。[方法] 以岳麓山周边地区为研究区,从2020年12月至2021年11月采集降水、山涧溪水和湘江河水水样,利用Piper图、Gibbs图、端元图等方法,分析各水体水化学特征以及影响因素。[结果] 降水主要阴阳离子为Ca²⁺,K⁺,SO^2-₄和NO^-₃,无明显水化学类型;山涧溪水主要阴阳离子为Ca²⁺和NO^-₃,主要水化学类型为Cl-Ca·Mg型和Cl-Ca型;湘江河水主要阴阳离子为Ca²⁺和HCO^-₃,主要水化学类型为HCO₃-Ca型。山涧溪水主要受大气降水输入和碳酸盐岩风化控制;湘江河水受碳酸盐岩风化作用影响较大。[结论] Na⁺离子含量,SAR和RSC指标以及其绘制USSL图和Wilcox图分析结果较好,山涧溪水和湘江河水适合用于灌,不易引起盐害或碱害。     

施氮量和密度对盐碱滩涂水稻产量和品质的影响

为明确施氮量和密度互作对盐碱滩涂水稻产量和品质形成特征的影响,以淮稻5号为试验材料, 设置6个施氮量处理:N0(0 kg·hm^-2)、N210(210 kg·hm^-2)、N255(255 kg·hm^-2)、N300(300 kg·hm^-2)、N345(345 kg·hm^-2)、N390(390 kg·hm^-2),2个移栽密度处理:D1(33.4 万穴·hm^-2,12 cm×25 cm)、D2(27.8 万穴·hm^-2,12 cm×30 cm),测定了水稻产量及品质形成的相关因素。结果表明,随施氮量增加,单位面积穗数和每穗粒数呈先上升后下降的趋势,以N300处理最高;结实率和千粒重呈下降趋势。不同密度间比较,高密度处理的穗数和千粒重高于低密度处理,每穗粒数和结实率呈相反趋势。施氮量与移栽密度组合中,以N300D1处理的产量最高,达7 978.83 kg·hm^-2。施氮量的增加提高了稻米的加工品质与营养品质,同时降低了外观品质与蒸煮食味品质。移栽密度的增加提高了稻米的营养品质,但降低了加工品质、外观品质和蒸煮食味品质。综合分析认为,施氮量300 kg·hm^-2和移栽密度33.4万穴·hm^-2, 是盐碱滩涂水稻获得高产优质的栽培措施。本研究结果为盐碱滩涂水稻的高产优质栽培提供了理论依据。     

不同生境中半红树植物抗氧化防御研究

选取5种半红树植物,研究了其在不同生境(潮间带和陆生)抗氧化防御系统的变化。结果表明,陆生的黄槿、许树O2.产生速率和莲叶桐H2O2含量均显著的高于其潮间带居群,从而使这3种半红树叶片中抗氧化酶类(SOD、APX、CAT、POD和GR)活性均高于其潮间带居群。而处于潮间带杨叶肖槿、阔苞菊(除SOD外)的SOD、APX、CAT活性显著高于其陆生居群,此时,H2O2含量要显著低于其陆生居群,而陆生的阔苞菊居群SOD、POD、GR活性高于其潮间带居群,因此,O2.产生的速率显著低于其潮间带居群。不同树种对不同生境有着不同抗氧化防御策略,总的趋势是,陆生的半红树抗氧化酶活性均要高于其潮间带居群,尤其是POD、GR活性在5种半红树中均显著高于其潮间带居群,暗示环境胁迫造成的选择压力导致半红树植物适应性的反应。高温、高光照、干旱是对陆生半红树的逆境胁迫,因此,上调抗氧化酶活性,以降低逆境对半红树的膜脂过氧化,减少电解质外渗,最终提高了半红树的抗逆性。     

渔山列岛潮间带大型底栖动物的群落结构

于2009年3月的大潮期间对渔山列岛潮间带布设5个断面,进行大型底栖动物调查。结果表明,该海域潮间带采集到大型底栖动物90种,其中腔肠动物3种,多毛类11种,软体动物45种,甲壳类19种,棘皮动物6种,其它6种。潮间带大型底栖动物总平均生物量5307.06g/m2,总平均丰度为2323.20ind/m2。在各类群底栖动...     

Fish utilisation of managed realignments

Abstract  One area of ecological benefit not yet fully evaluated in European waters is the utilisation of restored saltmarsh habitats by fish species. This study examines the utilisation of managed realignments and relic saltmarsh by fish species. Factors affecting habitat heterogeneity and fish populations are discussed, and recommendations are made with respect to scheme design and management that will maximise the biological and socio-economic values. Fish populations in the high intertidal areas were assessed using a suite of techniques, including observations on feeding behaviour. Each microhabitat was discussed as a function of the extent of fish colonisation. A positive relationship between the degree of fish utilisation and habitat heterogeneity was ascertained using species richness, abundance and behavioural observations. This study will aid habitat valuation for economic justification of managed realignments, over and above existing drivers, such as compensatory habitat for encroachment, flood defence and the European Union Habitats Directive. The work now forms part of a wider European Interreg IIIb project, COMCOAST.     

大亚湾潮间带生物种类组成、数量分布及生物多样性研究

分析了广东省大亚湾潮间带生物的种类组成、数量分布和生物多样性等特点。结果表明,该海域潮间带调查采获的潮间带生物标本共70科150种,以软体动物和甲壳类出现的种类最多,二者占了总种类数的80%,其中部分属经济价值较高的种类。潮间带生物全年平均生物量为1954.26g·m-2,平均栖息密度为1003.77ind·m-2。全年各类群生物中,平均生物量及栖息密度都以软体动物居首位。其Shannon-Weaner多样性指数(J)属中等水平,分布范围在1.419~3.562,平均为2.663。     

上海郊区河流沉积物N、P释放的初步研究

A laboratory study was conducted to observe the release of nitrogen and phosphorus from the sedimentsunder both anaerobic and aerobic conditions. The samples used were five creek sediments and a fish-pondsediment (as a comparison) obtained from suburban Shanghai. High loads of nitrogen and phosphoruswere found in the creek sediments. Total nitrogen of the sediments ranged from 1.17 to 5.95 g kg^-1; totalphosphorus from 608.63 to 2 033.95 mg kg^-1. Making up more than 90% of the total nitrogen, organicnitrogen was the dominant nitrogen fraction in the sediments; where as inorganic phosphorus was the dominant phosphorus fraction, which made up more than 85 percent of the total phosphorus. Cabound phosphorus fraction dominated inorganic phosphorus, which occupied more than 50% of the total. A large amount of ammonium was released from the sediments under both aerobic and anaerobic conditions, and the anaerobic releases were slightly greater than the aerobic. In addition, ammonium contents in the aerobic waters decreased sharply after reaching the peaks because of strong nitrification, compared with the relatively maintained ammonium peaks in the anaerobic waters. Anaerobic phosphate releases were much greater than the aerobic and the released ortho-phosphate was mainly from Fe-bound phosphorus. Ammonium and ortho-phosphate releases from the sample of the dredged creek were the lowest, showing that creek dredging could effectively remove contaminants from the surface of sediments and weaken the release potentials of nitrogen and phosphorus. Ammonium and ortho-phosphate releases from the fish-pond sediment were greater than those from the creek sediments though its total nitrogen and phosphorus were not the highest, which was probably due to the larger amount of biologically degraded organic matter in the fish-pond sediment.     

Historical changes in bivalve growth rates indicate ecological consequences of human occupation in estuaries

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