池杉在三峡水库消落带生态修复中的适应性

冬季淹没和夏季干旱的交替作用会导致三峡水库消落带生态系统质量下降. 为了探索有效的生态系统修复方式,选用池杉树种开展了消落带林泽工程试验,并采用统计分析和RDA(冗余分析)排序对水淹胁迫下池杉的生长响应进行了研究. 结果表明:种植在海拔169 m以上的池杉经历两轮冬季淹水后成活率约为84.52%;树高、冠幅和枝叶密度平均变化量较小,分别为0.10 m、0.04 m和-0.11%,而胸径和枝下高变化明显,平均改变量分别为0.78 cm和-0.64 m;树高、胸径、冠幅和枝叶密度等指标变化率在没顶和部分淹水情况下存在显著差异. 部分淹水时,池杉对水淹胁迫的适应能力较强,随着淹水深度的增加,各生长指标变化量均呈下降趋势,部分植株有枯梢,没顶和部分淹水情况下枯梢率分别为43.56%和11.76%. RDA结果表明,水力条件和初始生长特征共同对淹水后池杉生长变化产生影响,二者对池杉生长指标变化的总体解释率为31.20%,独立解释率分别为11.90%、14.40%,共同解释率为4.90%. 池杉作为适应三峡水库消落带水位变动的本土耐淹树种,其经历水淹后的生长变化不仅与水位变动有关,同时也与其淹水前的生长状态有关. 研究结果有助于三峡水库消落带类似生态修复工程的进一步深入开展.      

基于面向对象的海岸带土地利用信息提取研究

针对海岸带复杂多样的土地利用信息,选取山东省乳山市海岸带为研究区域,运用 Landsat TM遥感影像数据,基于面向对象分类方法,利用不同地物的光谱、形状、纹理和空间关系等特征,通过多尺度分割、隶属度函数法和标准最邻近分类法提取研究区土地利用信息,并对分类结果进行精度评估。结果表明：①隶属度函数法和标准最邻近分类法结合,提取出乳山市海岸带12 种土地利用类型信息,很好地区分了盐田和养殖水面、林地和园地,可提取出主要的道路和河流等细长线状地物;②将提取结果与最大似然法对比,面向对象分类方法提取精度达到82.50%,Kappa系数为0.809 1,分别比最大似然法提高了11.44%和0.105 5,很好地避免“同物异谱”和“异物同谱”对分类精度造成的影响,有效地避免了“椒盐”现象。面向对象分类方法提取中分辨率遥感影像精度较高,为海岸带土地利用信息的快速、准确提取提供了有效的技术手段。     

江苏海岸带滩涂围垦区土地利用类型变化研究——以江苏省如东县为例

滩涂围垦与开发是海岸带地区特有的土地利用模式,揭示新中国成立以来滩涂已开发围垦区土地利用类型结构能够为该地区未来土地利用与规划提供一个标尺。论文以江苏省如东县为例,从土地利用类型结构与土地利用类型综合指数两部分探讨新中国成立以来不同围垦年限滩涂围垦区土地利用类型结构变化特征,揭示土地利用变化过程,对该地区土地可持续利用具有重要意义。结果表明：新中国成立以来,如东县不同年限围垦区土地利用类型变化存在阶段性特征。从围垦时间序列来看,农用地占比在30 a 围垦区最高,其变化呈现“S”型特征;建设用地呈现间歇性增长,周期为20 a,其中村庄用地在围垦10 a 逐步出现;未利用地一直下降,在40 a 围垦区保持稳定,主要类型为河流用地。滩涂围垦区土地利用强度在30 a 围垦区达到最高,呈现“S”型变化特征。土地利用多样性指数在30 a 围垦区达到最高值,呈现倒“U”型特征。滩涂围垦区土地利用类型演变存在三个阶段。江苏省沿海滩涂淤长为滩涂围垦奠定了自然基础条件,围垦初期,受到盐分的限制,只有耐盐植物和改良作物能够在滩涂土壤上生存,随着土壤不断脱盐,滩涂围垦区土地利用类型逐步多样化,在未来滩涂资源开发利用过程中,需要重点开展滨海盐土的开发复垦工作,严格审批新增建设用地,积极保护自然生态环境,实现沿海滩涂地区可持续发展。     

2000~2011年深圳湾及邻近水域颗粒有机物的来源和时空分布

依据2000~2011年每月一次的调查资料,简要描述和讨论了深圳湾及邻近水域中颗粒有机物(POM)质量浓度的时空分布,并结合盐度和叶绿素a (Chl a)实测数据探讨POM的来源和滞留时间.结果表明深圳湾的POM质量浓度和陆源质量分数分别约为4.2mg/L,79%,而伶仃洋东部沿岸的分别约为1.9mg/L,42%.深圳湾和伶仃洋东部沿岸中现存浮游植物颗粒有机物(PPOM):Chl a比率分别约为92,54g/g,由此估算的PPOM质量浓度分别为0.8,0.2mg/L左右.依据浮游植物生产力和累计海源POM估算的POM滞留时间在深圳湾中为1~5d,而在伶仃洋东部沿岸中约为10d.研究期间伶仃洋东部沿岸POM质量浓度的年际变化略呈上升趋势,从1.7mg/L上升至2.0mg/L;深圳湾POM质量浓度在2000~2005年呈上升趋势,从3.0mg/L上升至5.5mg/L,在2006~2011年则呈下降趋势,从5.4mg/L下降至3.0mg/L.     

非饱和带柴油入渗实验研究及HSSM模拟

通过土柱模拟实验研究了柴油在不同含水率、不同粒径砂土中的入渗及残留特征,并采用HSSM(Hydrocarbon Spill Screening Model)模拟了柴油在含水率为6%中砂介质中的入渗过程.结果表明:随着介质含水率增加,柴油在介质中湿润锋推进速度先增大后减小,最快速度对应含水率处于相应介质最大残余含水率40%~50%范围内,残余柴油量随介质含水率增大而减小.在细砂、中砂和粗砂3种介质,柴油入渗平均湿润锋推进速度分别为0.42,0.52,0.73cm/min;平均残余柴油量分别为98.10,68.70,48.79mL. 湿润锋推进速度及残余柴油量均与介质粒径呈负相关.HSSM拟合柴油在含水率为6%中砂介质中的湿润锋推进速度为0.5832cm/min,与实验值0.5689cm/min相比,相对误差为2.51%.HSSM能较好的模拟柴油在非饱和带入渗过程,对于土壤及地下水污染预报具有重要意义.     

氯气泄漏后毒害区的估算及泄漏的处置

运用毒害区计算方法对本部贮存的氯气泄漏后扩散的半径进行估算,同时以扩散的半径作参考,提出氯气泄漏的处置方法.     

Extreme events and environmental changes: Tracing sedimentary processes in Central Vietnam coastal lagoons

Sediment cores, obtained in 2004–2005 and in 2008 from seven coastal lagoons of Central Vietnam (Lang Co, Nuoc Man, Nuoc Ngot, Thi Nai, O Loan, Thuy Trieu and Dam Nai), were analysed to assess changes in ²¹⁰Pb, porosity, grain size, and depth distributions of selected major and trace elements (Al, As, Ni, and Zn). The aim was to trace sedimentary processes in areas periodically subject to extreme events. The occurrence of lateral sedimentary inhomogeneities has been hypothesised to explain the differences observed at depth for some tracer profiles, whereas topmost levels present evidence that accounts for the loss of a sediment layer (from 2.0 to 7.5 cm thick) between the two samplings. These losses might be attributed to major typhoons that impacted the coasts of Central Vietnam during the study period.     

Relationships Between Copper Species and Forms,Hydrographic and Biomass Parameters in the Taiwan Erhjin Chi Coastal Area

The first incident of green oysters (Crassostrea gigas) was reported in Taiwan in the Charting coastal area in January, 1986 and mortality was reported three months later. the cause of the greened oysters was identified as copper pollution. the copper content of the green oysters was extremely high - 2100 ppm, 2225 ppm, and 4400 ppm dry weight, in January, 1986, February 1987, and January 1989, respectively. in this paper we summarize the seasonal and regional distributions of copper species (complexed by inorganic and organic ligands, labile and non-labile, polar and non-polar) and forms (dissolved and particulate) and the hydrographic and biomass parameters (mainly particulate organic carbon, chloropyll -α, adenosine triphosphate and primary production) in sea water in the Erhjin Chi coastal area. in general, high concentrations of particulate material (0.24 to 724 ppb) and non-labile organic copper (0.03 to 21.5 ppb) were observed. Low values of polar organic copper (<0.02 to 16.5 ppb) indicated that non-polar organic complexes (0.3 to 20.4 ppb) from man-made organic pollutants were the major complexes in the area studied. On the basis of this data, the cause of greening and mortality in oysters is evaluated in relation to the bioavailable copper (sum of particulate and labile copper) and copper assimilative capacity (detoxicant). Finally, the correlations between the species and forms of copper, hydrographic and biomass parameters are also discussed.     

Use of biomarkers in zooplankton for assessment of the ‘health status’ of marine and brackish environments: a short overview

The biomarker approach has been used for 25 years to study the environmental quality of marine, brackish and freshwater ecosystems. Biomarkers may indicate health status and can be applied to organisms of all zoological phyla by destructive or non destructive methods. For 5 years we have been using this approach in zooplankton to detect ecotoxicological alterations at low levels of the food chain due to contaminants. Here we review our approach to validate and apply biomarker techniques in zooplankton. We discuss advantages, limitations, some results and future research. We indicate that biomarkers in zooplankton can be used as new indices of trophic status and ecological integrity of Italian marine coastal and lagoon environments, to be included among the tools specified by Italian law D.Lgs. 152/2006.     

Organic and Inorganic Characterization of Marine Colloids

Abstract

Isolates of the organic matter in the particulate, colloidal and dissolved states were obtained by tangential flow ultrafiltration through 0.40 μm polycarbonate and ～ 1 nm (1000 NMWL?) regenerated cellulose membranes and by solid-liquid reverse phase extraction techniques. the material was analyzed qualitatively by mass spectroscopy, proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, high performance liquid chromatography with fluorescence detection of labelled primary amines and amino acids, and inductively coupled plasma/mass spectroscopy. All three states are characterized by similar organic chemistries. the marine colloidal state in coastal waters off the Californian coast contains primarily carbohydrates, fatty acids, minor amounts of proteinaceous compounds and electropositive elements including aluminium and iron. Aromatic molecules and olefinic functional groups are in low concentration. the colloidal state differs qualitatively from the particulate and dissolved states. Yet all three could be derived, with degradation, from algal or macroalgal surface components.