Factors affecting river entry of adult Atlantic salmon in a small river

In this study, effects of stock origin, fish size, water flow and temperature on time of river ascent of adult Atlantic salmon Salmo salar were tested. Brood stocks were collected in eight Norwegian rivers situated between 59 and 69° N. The fish were reared to smolts, individually tagged and released in the River Imsa, south-west Norway (59° N). Adults from all stocks approached the Norwegian coast concurrently, but Atlantic salmon ≥70 cm in natural tip length entered coastal water slightly earlier during summer than smaller fish. Atlantic salmon <70 cm, however, ascended the river significantly earlier and at lower water flow and higher water temperature than larger fish. Although largest in size, the fish from the northern populations (62–69° N) ascended the River Imsa almost 1 month earlier than those from the south (59–60° N). They seemed less restricted by the environmental factors than the fish originating from the more southern rivers. There was no apparent trend among years in time of river ascent. Maximum ascent per day occurred at water discharges between 12·5 and 15 m³ s⁻¹ and at water temperatures between 10 and 12·5° C. There was a significant positive correlation between water flow and river ascent during the first part of the upstream run from July to September with best correlation for September, when multiple regression analysis indicated that water temperature had an additional positive effect. Stock origin, fish size and water discharge were important variables influencing the upstream migration of Atlantic salmon in small rivers.     

荒漠河岸林植物木质部导水与栓塞特征及其对干旱胁迫的响应

 以同处于干旱区的塔里木河下游(铁干里克)和黑河下游(乌兰图格)断面为研究区, 比较了荒漠河岸林主要建群种胡杨(Populus euphratica)、柽柳(Tamarix spp.)、疏叶骆驼刺(Alhagi sparsifolia)和花花柴(Karelinia caspia)在长期遭受不同干旱胁迫下的根、枝条木质部导水力和栓塞化程度的变化特征, 并分析了木质部导水对干旱胁迫的响应及适应策略。结果表明: 1) 黑河下游荒漠河岸林植物的导水能力显著高于塔里木河下游, 其中柽柳、胡杨、疏叶骆驼刺和花花柴根木质部的初始比导率(K_s0)分别高11.97、6.74、7.10和3.73倍, 枝条的K_s0分别高9.48、3.65、2.07和1.88倍, 地下水埋深导致的干旱胁迫程度不同是诱发荒漠植物导水能力差异的根本原因; 2)柽柳耐干旱能力最强, 适应范围较宽, 而花花柴、疏叶骆驼刺的耐旱性相对较弱, 适生范围较窄, 这可能与植物的根系分布有关; 3)干旱胁迫较轻时, 枝条木质部是荒漠河岸林植物水分传输的主要阻力部位, 干旱胁迫严重时, 根木质部是限制植株水流的最大阻碍部位; 4)荒漠河岸林植物主要通过调节枝条木质部的水流阻力来适应干旱胁迫, 且其适应策略与干旱胁迫程度有关, 干旱胁迫轻时, 植物通过限制枝条木质部水流来协调整株植物的均匀生长; 干旱胁迫严重时, 植物通过牺牲劣势枝条、增强优势枝条水流来提高植株整体生存的机会。     

人粪样中雌马酚含量调查及其与菌群结构相关性研究

目的 调查人粪样中大豆素和雌马酚的含量及其与年龄和性别的关系;了解人粪样中雌马酚含量高低与菌群结构的关系.方法 采用高效液相色谱(HPLC)对来自杭州的125份粪样进行大豆素和雌马酚含量检测,并使用生物统计学软件SPSS进行统计学分析;使用PCR-DGGE对粪样中雌马酚含量的高低与菌群结构的关系进行初步研究.结果 HPLC检测结果表明,尽管粪样中雌马酚含量的高低与性别关系不大,但却与年龄大小存在很大的相关性,41 ～50岁年龄组的粪样中雌马酚含量明显高于其他年龄组.PCR-DGGE结果表明,粪样中雌马酚含量的高低与菌群结构无明显相关性.结论 人粪样中雌马酚含量的高低与年龄大小有很强的相关性.     

海南岛热带山地雨林林分生物量估测方法比较分析

本文通过对海南岛热带山地雨林林分生物量估测方法的比较分析,表明材积转换法不适宜估算海南岛热带山地雨林林分生物量,其结果与皆伐法相比较一般偏高20％—40％;而用实测资料建立的生物量回归模型,对原始林林分有较好的估测结果,除树枝和树叶生物量外,树干、树皮及地上部分生物量的回归模型值,与皆伐法的结果比较,相对误差一般在±10％以内,为允许误差范围,而对热带山地雨林的更新林生物量的估测则效果较差,应建立相应的估测模型。平均木法有工作量小的优点,且误差也在16％以下,但要注意取样的树种多样性和取样强度,在实际中应当慎用。另外本文对测定热带山地雨林生物量(原始林)的所需面积大小问题作了研究,提出了生物量-面积曲线的概念,确定其最小调查面积为2500m~2以上。     

富平石川河的生态修复

自国家提出构建山水林田湖草生命共同体以来,已启动第三批山水林田湖草生态保护修复工程试点申报,但一些工程设计缺乏整体性,造成“真破坏”和“伪生态”的现象时有发生.本研究以石川河综合整治项目为例,针对石川河乱采乱挖河道砂石,工业污染,附近村民焚烧垃圾造成气、水和土污染极其严重,生态、人居环境持续恶化,鱼虾绝迹,污水横流,垃圾成堆等问题,采用重建生态河道、恢复生态、景观重塑、土地平整、PE复合土工膜、土壤修复等技术构建山水林田湖草生命共同体,并分析了生态、经济和社会效益,通过项目实施,为石川河流域提供了洁净的土壤环境、稳定的土体结构,有效改善了生态环境,提高了生活质量,实现生产发展、生态良好,不断满足社会发展建设美丽乡村的需要,同时为构建流域山水林田湖草生命共同体提供理论依据和实践支撑.     

基于大型底栖动物群落的上海市河道水质生物学评价

2011年夏秋季,在上海市全境83个河道断面开展了河道底栖动物采样,共获取底栖动物20个分类单位（种）。9个极严重污染断面未采集到活体生物,生境基本丧失。其余74个有活体生物断面,采用三种常用生物指数：Shannon-Wiener多样性指数、Hilsenhoff耐污指数、Goodnight修正指数分别进行计算及评价。Shannon-Wiener多样性指数判别为25个严重污染和49个重污染断面;Hilsenhoff耐污指数划分38个重污染、5个中污染和31个轻污染断面;Goodnight修正指数划分33个重污染、2个中污染和39个轻污染断面。与典型河道断面的水质理化指标监测值进行对照,Shannon-Weiner多样性指数对河道水质评价的准确度较低,Hilsenhoff生物指数和Goodnight修正指数的水质评价效率及准确度均较高,断面污染等级与水质理化指标基本对应。     

雄安新区河流健康评价

雄安新区地理环境敏感,生态环境较为脆弱,研究新区河流健康对维护区域水生态平衡,实施京津冀协同发展战略及疏解北京非首都功能具有重要意义。以雄安新区4条河流为研究对象,基于高分二号遥感影像、地理信息数据和实测数据,构建由水文水资源、河流水质、河流底泥、河流生物、河流生境和社会服务构成的河流健康评价指标体系,并用主客观赋值法得到各指标的综合权重,进而计算河流的综合健康指数,以此对河流健康情况进行评价。结果表明不同河流的准则层指标的健康指数和河流综合健康指数存在差异性,其中白沟引河综合健康指数为0.640,处于健康状态;府河的综合健康指数为0.484,处于亚健康状态;瀑河和孝义河均处于病态,综合健康指数为0.269和0.228。总体表现同一河流不同河段以及不同河流存在明显的空间异质性,府河和白沟引河的健康状态明显好于孝义河和瀑河,同时除孝义河不同采样点的健康情况没有差别,府河、瀑河和白沟引河三条河流不同采样点之间的健康状况存在一定的差别,河流入淀处健康状况普遍比中游健康状况好。这为后期生态需水及其整个新区的生态功能提升提供了参考依据。     

海州湾近岸海域的微生物群落结构和抗生素抗性基因时空变化

【背景】近岸海域抗生素抗性基因(antibiotic resistance genes, ARGs)的污染和累积将直接影响海产品质量和安全,海州湾作为江苏省的四大渔场之一,是江苏渔业发展的主要载体,有多条大小河流注入,沿岸为重要农业区,对公众健康产生重大影响。【目的】对海州湾夏秋季的水样及沉积物展开微生物及ARGs检测。【方法】基于宏基因组测序技术开展海州湾夏秋两季近岸6个站点中水体和沉积物中ARGs种类和相对丰度以及微生物群落的组成研究。【结果】变形菌门(Proteobacteria)和放线菌门(Actinobacteria)是夏秋季度两种介质中最优势的门类,水样中优势的科级细菌为红细菌科(Rhodobacteraceae),沉积物样品中为脱硫杆菌科(Desulfobacteraceae);夏季水样中的ARGs相对丰度要明显高于秋季,但沉积物中不同季节的ARGs相对丰度未表现出明显的变化趋势;在水样中主要门级微生物群落的抗性机制主要是抗生素靶位替换和抗生素靶位保护,沉积物样品则以抗生素灭活机制为主,而主要科级微生物群落的抗性机制更加多样;冗余分析(redundancyanalysis...     

陕西泾河流域2019年旧石器考古调查简报

泾河流域旧石器考古工作开展很早,1920年法国神父桑志华(E.Licent)在甘肃庆阳地区赵家岔、辛家沟黄土堆积中发现石英质石制品,标志着中国旧石器考古的开端。在之后的近100年时间里,学者们陆续在属于泾河流域的甘肃庆阳、平凉等地发现牛角沟、寺沟口、楼房子和陕西长武窑头沟、乾县大北沟等旧石器地点,这些发现丰富了泾河流域旧石器文化内涵。然而,上述发现多集中在泾河中上游,且开展时间较早,下游地区特别是关中平原几乎是一片空白。本次调查在泾河流域中下游新发现旧石器地点16处,集中分布在关中平原泾河及支流的黄土堆积上。在黄土堆积中获取石制品63件,类型包括石核、石片和刮削器等,属于北方地区石片石器工业。根据石制品埋藏层位及泾河流域地貌发育和地层对比,初步推测这些地点时代为晚更新世。     

New preparation techniques for molecular and in‐situ analysis of ancient organic micro‐ and nanostructures

Organic microfossils preserved in three dimensions in transparent mineral matrices such as cherts/quartzites, phosphates, or carbonates are best studied in petrographic thin sections. Moreover, microscale mass spectrometry techniques commonly require flat, polished surfaces to minimize analytical bias. However, contamination by epoxy resin in traditional petrographic sections is problematic for the geochemical study of the kerogen in these microfossils and more generally for the in situ analysis of fossil organic matter. Here, we show that epoxy contamination has a molecular signature that is difficult to distinguish from kerogen with time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). This contamination appears pervasive in organic microstructures embedded in micro‐ to nano‐crystalline carbonate. To solve this problem, a new semi‐thin section preparation protocol without resin medium was developed for micro‐ to nanoscale in situ investigation of insoluble organic matter. We show that these sections are suited for microscopic observation of Proterozoic microfossils in cherts. ToF‐SIMS reveals that these sections are free of pollution after final removal of a <10 nm layer of contamination using low‐dose ion sputtering. ToF‐SIMS maps of fragments from aliphatic and aromatic molecules and organic sulfur are correlated with the spatial distribution of organic microlaminae in a Jurassic stromatolite. Hydrocarbon‐derived ions also appeared correlated with kerogenous microstructures in Archean cherts. These developments in analytical procedures should help future investigations of organic matter and in particular, microfossils, by allowing the spatial correlation of microscopy, spectroscopy, precise isotopic microanalyses, and novel molecular microanalyses such as ToF‐SIMS.