海水养殖鱼类细菌性疾病研究概况

本文概述性地介绍了发生在海水养殖中的常见细菌性疾病包括弧菌现、链球菌症、卡诺氏菌症、细菌性肾病、巴斯德氏杀菌症、爱德华氏症、滑走细菌症和杀鲑气单胞菌症等的主要症状、流行情况及病原菌特征，通过遗传育种筛选有抗病力的养殖品种是人们正在努力的方向，目前的研究重点主要在鱼类抗病能力方差分析研究及抗病育种的方法研究，免疫接种是提高养殖鱼类对某一特定性病原菌的最有效的方法，目前已有三十多种菌苗上市，通过使用免疫刺激剂提高鱼类的非特异性免疫力已显示一定的应用前景，虽然抗菌素由于存在抗药菌株和鱼体残留，但它仍是目前对细菌性疾病疾病的常规疗法，而海洋藻类提取物对细菌的抑制作用已被人们所认识，它将会成为一种有潜力的抗菌药物。     

Palaeolimnological studies of the eutrophication of volcanic Lake Albano (Central Italy)

We use palaeolimnological techniques to reconstruct the eutrophication history of a volcanic lake (Lake Albano, central Italy) over the past three centuries. The presence of annual varves down to the bottom of the core (c. 1700 A.D.) indicated the lack of bioturbation and likely long-term meromixis. Sedimentation rates were estimated by varve counts (calcite/diatom couplets), indicating a mean rate of 0.15 cm yr^–1. The reconstruction of eutrophication was traced using past populations of algal and photosynthetic bacteria (through their fossil pigment), and geochemistry, as well as fossil remains of chironomids. Phaeophorbidea and the red carotenoid astaxanthin were used to detect past zooplankton development.The first sign of trophic change related to human activities is datedc. 1870 A.D. From that period onward a sharp increase of authigenic CaCO₃, nitrogen, N:P ratio, and dinoxanthin, a characteristic carotenoid of Chrysophyceae and Dinophyceae, is observed.Chironomid analyses showed the near absence of a deep water fauna throughout the core length. The populations of chironomid larvae are restricted to oxygenated littoral zones. In fact, the few fossil remains found are primarily of littoral origin, representing shallow water midges that were transported to profundal waters. The reduction of total chironomid in the uppermost layers of the core is to be related to human land uses.     

北京地区湿地高等植物区系分析

根据工作需要,在北京4个水系的主要河流的平原地段和山区的上、中游地段,选取不同生境的典型样地,以及城区的人工湖泊共设立了35个采集点,采用样方法和样带法相结合,共调查样方355个,采集样本4 152个。在该调查资料的基础上,运用区系学原理对北京地区湿地高等植物区系的种类组成、地理成分(科、属、种3个层次)等进行了系统的分析。结果表明,北京地区湿地高等植物共有108科311属552种(含山区湿地),占北京植物总数的近1/3。其中苔藓植物(B ryohyto)有9科15属18种;蕨类植物(Pteridophgta)5科5属8种;裸子植物(Gymnosperm ae)3科5属6种;被子植物(Angiosperm ae)91科286属520种。种子植物中含20种以上的有5科,共210种;含5种以上的属有14个属,共114种。北京地区湿地植物的分布(即地理成分)较复杂。北京湿地种子植物属的分布区类型有15个类型,9个变型,温带地区类型占主导,温带成分较丰富(属数、种类、比例均占首位)。本区植物区系的主要特征为:①草本植物发达;②温带成分占优势地位;③区系起源古老;④特有属、种匮乏;⑤分布区类型具多样性。     

Habitat, occurrence and conservation of Saharo-Arabian-Turanian element Forsskaolea tenacissima L. in the Iberian Peninsula

The aim of this study is to assess the Iberian populations of Forsskaolea tenacissima L. according to its biogeographical interest, habitat, geographical range and conservation status. Results point out that they are restricted to gravel wadis of Tabernas Desert (SE Spain), are scarcely included in protected areas and represent historically isolated populations with relict behaviour. We also describe a new association, Senecioni-Forsskaoleetum tenacissimae. Conservation status of species is cause for concern and two conservation actions must be carried out. Firstly, protected areas should house Forsskaolea populations and secondly, phytosociological characterization of a community allows inventorying its habitat and directing conservation efforts to community level.     

总磷作为饮用水生物稳定性控制指标的研究

根据国内提出的控制饮用水生物稳定性的可同化有机碳(AOC)标准,通过配制水样研究了AOC及细菌再生长潜力(BRP)同水中磷含量的关系;同时针对净水工艺试验出水水样,考察了水中的磷同其生物稳定性的关系。结果表明,对于配水水样,在一定的磷浓度范围内,磷是水中细菌生长的限制因子;在净水试验工艺出水水样中添加50μg/L的PO₄3--P后,AOC增加了55%,BRP增加了123%,表明水中磷是其生物稳定性的限制因子。由于常规的净水工艺对水中的磷可以有效去除,把水中总磷(TP)控制在5μg/L内来提高饮用水生物稳定性具有一定的可能性和现实性。     

山西太岳山种子植物区系特征

调查的基础L，统计了太岳山种子植物有97科、316属、575种（含变种），分析了该区系的主要特征，即植物区系地理成分复杂，温带成分占优势；植物资源种类丰富，区系起源古老；植物区系具明显的过渡性；植被类型复杂，具明显的垂直分布．对该区野生经济植物进行了分类统计，为植物资源合理利用与生物多样性保护提供了基础资料穹科学依据．     

山东淄博地区晚古生代成煤环境演替

淄博地区本溪期—石千峰期沉积环境经历了障壁岛—泻湖—台地环境，三角洲环境，曲流河环境体系的演替。相应的泥炭形成环境有不稳定的局限泻湖泥炭坪，较开阔泻湖泥炭坪，中等稳定的开阔泻湖泥炭坪，三角洲平原分流河道两侧的泥炭沼泽，洪泛平原上的泥炭沼泽。成煤植物上，本溪期以Ｃｏｒｄａｉｔｅｓ，Ｌｅｐｉｄｏｄｅｎｄｒａｌｅｓ，Ｎｅｕｒｏｐｔｅｒｉｓ为主，太原期华夏植物群发展，Ｌｅｐｉｄｏｄｅｎｄｒｏｎ，Ｃｏｒｄａｉｔｅｓ继续发育，真蕨纲和种子蕨纲占越来越重要的地位。山西期以Ｏｄｏｎｔｏｐｔｅｒｉｓｓｐ．，Ａｎｎｕｌａｒｉａｏｒｉｅｎｔａｌｉｓ，Ｐｅｃｏｐｔｅｒｉｓｏｒｉｅｎｔａｌｉｓ，Ｐ．ｎｏｒｉｎｉ为主。自煤系形成至今，本区经历了海西印支期的普遍沉降埋藏、燕山期的普遍抬升局部断陷、喜山期的剥蚀、新构造运动期的差异沉降等阶段。古构造、古气候对本区成煤环境有重要的控制作用。     

Effet de la teneur en eau d'un sol sur la réduction bactérienne d'oxydes de fer

Iron-reducing activity of autochthonous bacteria from two temporary hydromorphic soils is evaluated by the study of iron reductive dissolution, as a function of water content. The release of ferrous iron in solution is coupled to the mineralization of soil organic carbon. Water soil saturation is not necessary for iron reductive dissolution, since the highest dissolution is obtained for a wet, but not water-saturated soil (100% of water holding capacity WHC), and dissolution is also very high in a soil at 75% WHC. To cite this article: S.J. Stemmler et al., C. R. Geoscience 336 (2004).     

上海地区湿地水生维管束植物及其区系特征

在参照相关资料基础上，结合实地调查，得出上海地区湿地水生维管束植物共49科107属179种。从植物生态型和生活型等方面来划分，上海地区水生维管束植物可主要分为内陆河湖水生植物、河口海岸滩涂植物和湿生植物3种类型。从区系组成来看，包含5种以上的12个较大科构成了上海地区水生维管束植物的主体，其中禾本科和莎草科种类最多；区内各属种数都在10种以下，包含3种以上的属有19属，共79种，分别占总属数的17．8％和总种数的44．2％。从区系分布区类型来看，水生蕨类植物种主要有4种分布区类型，世界分布为主要类型；而水生种子植物属有13种分布区类型，其中6个热带分布类型共有39属，占总属数的61．9％，6个温带分布类型共有24属，占总属数的38．1％，表明上海地区水生种子植物区系具有偏热带性质。同时，讨论了水生维管束植物在湿地生态系统以及湿地生态恢复中的重要作用。     

Taxonomic composition and seasonality of diatoms in three Dinaric karstic lakes in Croatia

The composition and temporal distribution of planktonic diatoms were studied in three small shallow karstic lakes – Modro Oko, Desne, and Kuti – throughout the seasons in 1994, 1995, 1997, and 1998. Physico-chemical parameters did not differ among the three lakes, except for NO₃ concentrations. Altogether, 137 diatom taxa within 41 genera were found in all three lakes combined. The highest number of taxa belonged to the genera Surirella (13), Navicula (12), andCymbella (9). Most taxa were tychoplanktonic, with true panktonic taxa contributing only 14% of the total. Despite their physical-chemical similarity, the lakes showed differences in the structure and dynamics of their diatom communities. Blooms occurred at different times in each of the lakes, and community similarity (Jaccard index) among all three was low (17.6–29.1%). The highest mean values of surface diatom abundance in Modro Oko (2199 cells L⁻¹), Desne (7900 cells L⁻¹), and Kuti (20690 cells L⁻¹) were not significantly different. Margalef's species richness index did not differ either among the lakes or seasonally. Only five diatom taxa in quantitative samples, and 22 taxa in net-samples, were common to all lakes. The most frequent diatoms were Cyclotella striata (56–93%), Fragilaria ulna (50–67%), and Asterionella formosa (27–83%). The most abundant taxa in Modro Oko, Desne, and Kuti were, respectively, Cymbella sp. 1 (402 cells L⁻¹), Cyclotella striata (3000 cells L⁻¹) and Asterionella formosa (20690 cells L⁻¹). Eighteen taxa were recorded for the first time in Croatia: Amphora commutata, Caloneis amphisbaena var. subsalina, C. silicula var. peisonis, Campylodiscus echeneis, Coscinodiscus lacustris, Denticula elegans, Gyrosigma acuminatum var. lacustre, G. distortum var. parkeri, G. fasciola, Navicula menisculus var. menisculus, N. pusilla, N. helensis, Stauroneis parvula var. prominula, Staurosira construens f. subsalina, Stephanodiscus sp. 1, Surirella gracilis, S. ovalis, and S. striatula. The genus Stephanodiscus was recorded for the first time in Croatia.