Recruitment,habitat selection and larval photoresponse of Paraleucilla magna (Porifera,Calcarea) in Rio de Janeiro,Brazil

Little is known about the recruitment and behaviour of sponge larvae, especially of the class Calcarea. The calcareous sponge Paraleucilla magna is very common in Southeast Brazil, where it is considered a cryptogenic species. This study quantified recruitment rates in shaded and illuminated habitats for 2 years in Rio de Janeiro, Brazil, and analyzed larval photoresponses of this species. Four structures, each containing a shaded and an illuminated surface, were exchanged every 3 months for 2 years. The number of recruits was quantified on each plate. In the laboratory, larvae of P. magna were placed in half‐shaded Petri dishes and the number of settlers in each side was counted after 24 h. Paraleucilla magna recruited continuously throughout the experiment. Recruits occurred in greater abundance on shaded surfaces than on illuminated surfaces, and the larvae were negatively phototactic in vitro. Despite the possible influence of other factors in the recruitment of sponges (such as sedimentation, competition and predation), the prevalence of P. magna in shaded habitats may also be related to larval choice.     

我国近海镉的水质基准及生态风险研究

以镉为研究对象,在分析我国海水水生生物区系特征的基础上,筛选了栖息我国境内的海水水生生物物种的毒性数据,采用基于物种敏感度分布(SSD)模型不同拟合曲线(log-logistic、log-normal、 Gumbel、Weibull和Burr Ⅲ)的方法分别推导了保护水生生物的海水水质急性基准值和慢性基准值,并分析了引入淡水数据推导海水水质基准的可行性;同时,结合我国海水中镉的分布特征,对海水中镉的生态风险了初步评价。结果表明:Burr Ⅲ对各组数据拟合的效果最佳;引入淡水数据可能会对海水生物造成"过保护"风险;基于Burr Ⅲ对海水数据所推导的急性和慢性基准推荐值分别为63.0 μg/L和8.0 μg/L;将我国近岸水体中镉的浓度与基准值比较显示,我国近岸水体中镉对水生生物的潜在风险较低。研究结果有望为我国水质基准研究及标准制定提供参考。     

Repeat photography as a tool for detecting and monitoring historical changes in South African coastal habitats

Repeat photography was used to illustrate long-term changes occurring in coastal habitats in the Western Cape, South Africa. Historic images were sourced from books and theses, the public and subject specialists, and repeat photographs were then taken from the same perspectives. Visible changes could be categorised into four types: (1) changes in species’ ranges; (2) biological invasions; (3) sea level changes; and (4) direct engineering impacts. In terms of range changes, the images depict a progressive easterly spread of the cold-water kelp Ecklonia maxima and parallel easterly contraction of the warmer-water mussel Perna perna, both evidence for declining water temperatures along the South-West Coast. Since c. 1980 most shores have also become conspicuously invaded by the alien Mediterranean mussel Mytilus galloprovincialis, while those on the West Coast have also been visibly invaded by the more-recently introduced Pacific barnacle Balanus glandula. No changes in vertical zonation due to changing sea levels could be detected, despite suitable images being available. Construction along the shore has radically altered the appearance of the shoreline in urban areas. Repeat photography thus proved a useful tool for both detecting and dramatically illustrating historic changes over the past century. These changes have altered substantially both the appearance and ecological attributes of many rocky shores in this region.     

Significant population genetic structuring of the holoplanktic scyphozoan Pelagia noctiluca in the Atlantic Ocean

Pelagia noctiluca is thought to have a global distribution, yet our understanding of genetic connectivity across the range of this problem animal is poor. Here, we investigate the genetic structure of populations off southern Africa using mitochondrial COI and nuclear ITS1 and ITS2 genes, and compare the results to recent work conducted in the North-East Atlantic. Analyses showed significant differentiation between the southern and northern Atlantic population groups (COI Φ _st = 0.72, ITS2 Φ _st = 0.23, p < 0.001), which suggests historical rather than contemporary gene flow. Southern African samples showed high haplotypic (h = 1) and low nucleotide (π = 0.008) diversity, similar to those from Europe. Phylogenetic analyses suggest South African samples to have diverged earlier than those from the northern Atlantic.     

藏北高原高寒草地围栏禁牧和生长季降水对物种丰富度和多样性的影响(英文)

2009和2010年夏天沿藏北高原高寒草地样带调查了高寒草地生态系统(高寒草甸、高寒草原和荒漠草原)在围栏禁牧和自由放牧管理下的物种丰富度和多样性(Shannon-Wiener指数,Simpson优势度指数和Pielou均匀度指数)。研究结果显示:自2006年起藏北高原围栏禁牧在植被类型和区域尺度上没有显著改变物种丰富度和多样性。物种丰富度和多样性主要受生长季降水驱动,超过87%的变异可由生长季降水来解释。物种丰富度和多样性在自由放牧和围栏禁牧2类样地对生长季降水的响应方式一致。物种丰富度随降水呈指数型增长关系,多样性指数则呈现正线性关系。研究结果预示藏北高原地区生长季降水的变化对于物种丰富度和多样性管理至关重要,在未来高寒草地保护研究中应予以重视。     

贵州省喀斯特山区植被恢复的物种选择现状分析

喀斯特山区生态系统的恢复和重建,已经成为决定西南地区环境、经济和社会能否持续发展的关键问题,其中植被的生态恢复无疑是极为基础和重要的环节之一,物种选择又是重中之重．通过互联网搜索、文献阅读和野外实地考察,针对喀斯特分布极广且石漠化最为严重的贵州省,本研究调查和分析了喀斯特山区植被生态恢复过程中所选择的物种分布现状,对其恢复效果进行了初步评价,希望能对西南喀斯特山区的生态恢复,尤其是对即将全面铺开的石漠化综合治理提供参考和建议．结果表明：在贵州省78个岩溶县（市、区）的328个地点,共调查收集到用于植被恢复的物种87种,其中生态林物种26种（主要是松、杉、柏、香椿、杨树和车桑子等）,经济林物种47种,包括26种药用植物（太子参、天麻等）和其他21种经济林物种（茶、油茶、梨、桃、李、板栗等）,另外有牧草14种（白花三叶草、黑麦草、紫花苜蓿等）．这些物种聚集或零散种植在不同的喀斯特石漠化综合治理大区：A区（黔西高原山地）、B区（黔中丘原山地）、C区（黔东低山丘陵）和D区（无石漠化）．就恢复效果而言,油茶、茶、中药材、花卉栽培及草地畜牧业均显示出了规模化、产业化发展的良好势头,板栗、核桃、花椒、桃、梨等经济林物种也在其生长适宜地取得了良好的生态和经济效益．然而,植被生态恢复中所营造的人工林,均存在树种单一、物种配置简单、经营粗放等问题,林分的整体功能和生态、经济效益较低,亟待进行改造;不同喀斯特石漠化综合治理区域也需要采取不同的物种配置措施．     

Isotopic composition of salt efflorescence from the sandstone castellated rocks of the Bohemian Cretaceous Basin (Czech Republic)

The origin of sulphates in sulphate-rich efflorescences on quartz sandstones with a clay matrix, exposed in rural areas of the Czech Republic is interpreted, based upon an isotopic study of S and O. Sulphates such as gypsum and/or alums exhibit δ³⁴S ranging from +1.3 to +6.1‰ and δ¹⁸O from +5.3 to +8.8‰. The low variability of S and O isotopes indicates a common source of the sulphur and a similar mode of sulphate formation. Atmospheric sulphates with a similar isotopic signature occur in the area, due to the combustion of sulphurous coal in power plants, located a few tens of kilometres from the sampling points. The sulphates crystallize from supersaturated pore waters that represent atmospheric precipitation, rich in sulphates, having percolated through the porous sandstone system. The previously proposed model of efflorescence growth (that it is due to the oxidation of pyrite) can be excluded, due to both the rare occurrence of pyrite and also to its different isotopic signature (δ³⁴S about −22‰). Although gypsum prevails in the central and eastern part of the studied area, the north and north-west of the Bohemian Cretaceous Basin (the most polluted region) exhibits a significant presence of alums (NH₄ ⁺ or K⁺−NH₄ ⁺-rich). Formation of alums can be explained by the partial dissolution of clay minerals or feldspars present in the sandstone matrix. Release of alumina from these phases is facilitated by the low pH of the precipitation (pH 4–4.5) and also locally by organic acids, traces of which were found in the studied efflorescences by the use of infrared spectroscopy.     

东天山喀尔里克山北坡-淖毛湖植物群落物种多样性研究

以东天山喀尔里克山北坡-淖毛湖为研究区,探讨了该区山地-荒漠生态系统的植物种类组成、植被类型及群落物种多样性特征.结果表明:该区共有高等植物33科93属133种,植物生活型组成以草本植物居多.群落物种多样性测度指数的主成分分析结果显示,物种丰富度指数(R)、Pielou均匀度指数(Jsi)、Shannon-Wiener多样性指数(H)和Simpson优势度指数(C)能很好地描述群落结构和组成特征.其中,多样性指数、均匀度指数和丰富度指数的变化趋势基本一致,优势度指数则和前三者呈负消长的关系.随着海拔升高,群落物种多样性指数、丰富度指数和均匀度指数变化均呈现单峰分布格局,即植物群落的物种多样性在山前荒漠生态系统和高海拔山地生态系统中较低,而在中海拔地区达到最大.     

2011年全球发现的新矿物种

在系统梳理2011年度全球发现并经国际矿物学协会(IMA)新矿物与矿物分类命名专业委员会(CNMNC)批准的122个新矿物种资料的基础上,从矿物名称、晶体化学式、晶系和空间群、晶胞参数、主要粉晶数据、物理性质、光学性质、产地与产状、与其他矿物种的关系、矿物名称来源、化学反应和光谱学特征等方面归纳总结了这些新矿物的重要矿物学特征。并按照中国新矿物及矿物命名专业委员会颁布的《矿物种汉名审订条例》,对122个新矿物种的中文名称进行了审订。通过适时公布国际新矿物工作的新进展和新成果,并逐步完善和规范矿物种中文译名体系,为我国新矿物的发现和研究提供有科学价值的参考和借鉴,不断推动矿物种中文译名规范化与标准化的进程。