Reef fish display station-keeping and ranging behaviour in the Pondoland Marine Protected Area on the east coast of South Africa

This study assessed the role of the Pondoland Marine Protected Area (MPA) in the Eastern Cape province of South Africa by evaluating retention versus ‘spillover’ of exploited fishery species that were tagged in a 400 km² no-take zone of the MPA. From April 2006 to July 2010, 2 124 fish comprising 36 species were tagged in the MPA, with an overall recapture rate of 23%. Findings for four important species (Polysteganus praeorbitalis, Chrysoblephus puniceus, Epinephelus andersoni and Epinephelus marginatus) are presented. Recapture rates ranged from 8% to 60% and time-at-liberty from 0 to 1 390 d. Individuals of all four species displayed highly localised station-keeping behaviour. For all four species, the 95th percentile of intra-study site movements was <750 m (linear distance) and many recaptures were within 250 m of the release site, showing that some fish spend most of their time in the MPA's no-take zone. However, some fish moved beyond the boundary of this zone in a north-easterly direction (range 3–1 059 km), where they would be available to the boat-based fishery in KwaZulu-Natal. The combination of resident individuals with some with ranging behaviour suggests that the MPA can provide a conservation role for these species, while exporting some individuals into nearby fisheries.     

Phylogeography of the bluespotted cornetfish,Fistularia commersonii: a predictor of bioinvasion success?

Biological invasions result in huge ecological and economic impacts; therefore, a great amount of effort is dedicated to predicting the potential success of newly established or candidate bioinvaders. Thus far, over 90 species of fish have entered the Mediterranean Sea via the Suez canal, the so‐called Lessepsian bioinvaders. The bluespotted cornetfish, Fistularia commersonii, is remarkable in its ability to disperse within the Mediterranean and has been dubbed ‘the Lessepsian sprinter’. In just a few years, starting in 2000, it expanded over the entire area, from the Suez Canal to Gibraltar. Theoretical predictions correlate the dispersal capabilities of an invader in its native range (using the population genetic metrics, F_st, as a proxy) with its dispersal capability in its invading area (continuous extent of spread, CES). Here, we estimated the population genetic characteristics of Indo‐Pacific native populations of F. commersonii in order to determine if this Lessepsian ‘sprinter’ fits the predictive model of dispersal. Indeed, we found that even in the case of such a very rapid range expansion, the predicted relationship between F_st and CES is fulfilled in F. commersonii.     

中国种子植物特有科属的分布型

中国种子植物特有属有２６８属，归７８科，其中有８个单种属中国特有科。本文根据特有属的地理分布及与环境的关系，区分为９个分布型和２３个亚型（包括本分布型），对各分布型和亚型进行了统计分析和详细阐述，讨论了分布区的间断和替代现象。提出特有科属分布型的主要特点。     

蒙古扁桃种子雨散布及种子萌发特性研究

以蒙古扁桃（Amygdalus mongolica Maxim）种群和种子为研究材料,通过物理特性、休眠特性、萌发特性的研究,探讨种群致濒因素。结果表明,蒙古扁桃种子比重、体积和千粒重大,散布时间较集中,散布格局是聚集型散布,散布主要依靠自身重力,靠动物散布和水力作用的散布,使种子能传播较远的距离。制约种子萌发的主要因素是种皮障碍和生理休眠（10%）,采用35 ℃条件下处理72 h后机械破除果皮可破除种子休眠,种子低温（2~5 ℃）层积处理能极显著（P <0.01）提高活力,种子变温（5~10 ℃）层积能极显著（P <0.01）提高发芽率和活力,种子萌发对光照不敏感。蒙古扁桃种子休眠较浅,种子萌发所需温度较低,冬前进入土壤库的种子迅速萌发,因不能度过严冬而死亡,是致濒的主要原因。封冻时进入土壤库的种子,在种皮保护下越冬,仍有很高成苗率,开展人工繁育是拯救蒙古扁桃资源的直接措施。     

液态二氧化碳(LC)播撒装置应用研究

针对液态二氧化碳(LC)的播撒问题, 给出了其播撒装置的基本特征、播撒率及主要影响因子;用FSSP-100 、2D-C粒子测量仪、三用滴谱仪及能见度仪等设备测定了LC播出物的相态、粒子形状和尺度谱。测定表明:LC播出物为液、固、气态二氧化碳三相共存混合物。液态、固态粒子存在时间约100～101s, 粒子尺度10-1～102μm, 播出物流束中单位体积质量可达3.6 g·m-3。这些测定结果为使用LC作为冷云催化剂提供了可靠依据, 为国内在较暖云顶层状云中开展人工增雨作业提供了合适的催化技术。     

Provenance of Permian Delaware Mountain Group,central and southern Delaware Basin,and implications of sediment dispersal pathway near the southwestern terminus of Pangea

ABSTRACT

The Delaware Basin is located near the southwestern end of the Alleghanian–Ouachita–Marathon orogenic belt. The basin is mostly filled by Permian clastic rocks of the Delaware Mountain Group with ramp- to shelf-carbonate rimming basin edges. The Delaware Mountain Group has been well-documented as a deep-water clastic reservoir unit in the prolific Permian Basin, but its sources and related sediment dispersal pathways remain inconclusive. In this study, a total of 55 samples of the Delaware Mountain Group were collected from whole core and sidewall core from the central and southern Delaware Basin, and sandstone modal analyses and U-Pb detrital zircon geochronology were applied to constrain their potential sources. Sandstone modal analyses show that the majority of samples fall within the transitional continental source field. Age spectra of detrital zircon from five selected samples include a prominent middle Palaeozoic age cluster (~490–275 Ma), a major Neoproterozoic to early Palaeozoic age cluster (~790–510 Ma), and a series of minor age clusters of the middle to late Mesoproterozoic (~1300–920 Ma), early Mesoproterozoic (~1600–1300 Ma), late Palaeoproterozoic (~1825–1600 Ma), and Archaean and Palaeoproterozoic (> ~1825 Ma). Integrating detrital zircon data from all potential sources and coeval sandstones from the northern Delaware Basin suggests that the majority of sediment was derived from the Appalachian foreland, the Ouachita orogenic system, and the peri-Gondwanan terranes. Variation in the abundance of the different age groups reveals a provenance shift between deposition of the Brushy Canyon Formation and the Cherry and Bell Canyon Formations. To accommodate the composition, and the stratigraphic and spatial age spectral variations, we proposed that the sediment dispersal pathway includes a transcontinental fluvial system from the Appalachian orogenic belt to the east, a regional scale fluvial system from the Ouachita orogenic belt to the north and northeast, and a local, proximal fluvial system from the peri-Gondwanan terranes to the south and southeast.     

黄河口不同粒度泥沙沉积与扩散分析

本文采集和收集大量黄河三角洲沉积物剖面和钻孔泥沙粒度资料以及黄河口来沙粒度组成数据,定量研究了黄河口泥沙的沉积与扩散特征.结果 显示黄河口来沙以粉砂为主,黏土次之,砂最少,年均中值粒径无长期变化趋势.黄河三角洲平原相泥沙与来沙的黏土、粉砂和砂含量无显著差异;前缘相泥沙比来沙的黏土含量较低,砂含量较高;前三角洲相泥沙比来...     

Natal site fidelity by breeding female southern elephant seals in relation to their history of participation in the winter haulout

Of the four types of terrestrial haulout periods undertaken by southern elephant seals Mirounga leonina, only the purpose of the winter haulout is unknown. Returning to a haulout site from distant pelagic foraging grounds bears significant costs in terms of increased energy expenditure, reduced foraging time and increased exposure to predation; therefore, each haulout must serve a purpose. We examined the hypothesis that the winter haulout serves to maintain familiarity with the natal site, thereby increasing site fidelity. To this end, we analysed a long-term mark-recapture dataset for female southern elephant seals at Marion Island, Southern Ocean. Results indicate that, whereas greater natal site fidelity as primiparous females was associated with recorded presence ashore at the study site during the winter haulout as immatures, this was not the case for multiparous females. Furthermore, recorded presence ashore during both the moult haulouts as immatures, and all haulouts as immatures, irrespective of haulout type, was also associated with increased site fidelity. This suggests that any haulout at the natal island as an immature seal, whether for the moult or winter haulout, assists in maintaining site fidelity. Therefore, while the winter haulout facilitates greater natal site fidelity, whether this is the sole reason for this terrestrial period remains uncertain.     

基于生境-生物一体化视角的鄱阳湖草洲景观连通度研究

分析景观连通度动态变化特征是研究景观生态过程的重要途径,也是维持区域生物多样性的重要手段。本文以鄱阳湖草洲为研究对象,立足于影响景观连通度的生境（水位变化）与生物（物种扩散）一体化视角,在识别不同水位梯度下草洲生境范围和斑块组成的基础上,利用景观格局指数分析不同水位梯度下草洲景观结构连通度的变化特征,通过基于图论的景观连通度方法对草洲景观功能连通度分别进行不同水位梯度和不同扩散距离下的情景模拟,并剖析景观结构连通度与功能连通度的相关关系。结果表明：（1）鄱阳湖草洲呈现“水落滩出、水进草退”的景观特征,草洲生境同时面临水体的淹没效应和分割效应。随着水位的增加,草洲分布范围不断缩小,大斑块破碎与小斑块消失并存。（2）从水位变化过程来看,随着水位的增加,草洲斑块的面积不断萎缩、形状趋于简单、密度减小、破碎化程度加剧,草洲景观结构连通度下降。此外,随着水位的增加,草洲斑块在生态功能上的链接数减少、难以连接的独立组分增加、连接的可能性降低,草洲景观功能连通度降低。（3）从物种扩散过程来看,物种扩散距离对草洲景观功能连通度具有绝对正向作用,随着扩散距离的增加,草洲景观功能连通度显著增大。（4）相关...     

Widespread strombolian eruptions of mid-ocean ridge basalt

Glassy lava fragments were collected in pushcores or using a small suction-sampler from over 450 sites along the Juan de Fuca Ridge, Blanco Transform Fault, Gorda Ridge, northern East Pacific Rise, southern East Pacific Rise, Fiji back-arc basin, and near-ridge seamounts in the Vance, President Jackson, Taney, and a seamount off southern California. The samples consist of angular glass fragments, limu o Pele, Pele's hair, and other fluidal fragments formed during pyroclastic eruptions. Since many of the sites are deeper than the critical point of seawater, fragmentation cannot be hydrovolcanic and caused by expansion of seawater to steam. The glass fragments have a wide range of MORB compositions, ranging from fractionated to primitive and from depleted to enriched. Enriched magmas, which have higher volatile contents, may form more abundant pyroclasts than depleted magmas. Eruptions with high effusion rates produce sheet flows and abundant pyroclasts whereas those with low effusion rates produce pillow ridges and few pyroclasts. This relation suggests that high effusion and conduit rise rates are coupled to high magmatic gas contents. The eruptions are mainly effusive with a minor strombolian bubble burst component. We propose that the gas phase is an added component of variable amounts of magmatic foam from the top of the magma reservoir. As the mixture of resident magma and foam rises in the conduit, the larger bubbles in the foam rise more quickly and sweep up the smaller bubbles nucleating and growing from the resident magma. On eruption, the process of bubble coalescence is more complete for the slower rising, gas-poor lavas that erupt as pillow lavas whereas the limu o Pele associated with sheet flow eruptions commonly contain several percent vesicles that avoided coalescence during ascent. The spatter erupted at the vent is quench granulated in seawater above the vent, reducing the pyroclast grainsize. The granulated spatter and limu o Pele fragments are then entrained in a rising plume of seawater heated by the eruption, which disperses them to distances as great as 5 km from the vent.