Devonian Gastropoda from the Dornap “Massenkalk” complex (Bergisches Land,Germany)

Seven Middle Devonian (latest Givetian or earliest Frasnian) gastropod species are described from the quarry of Oetelshofen near Dornap (Bergisches Land, northwestern Rheinisches Schiefergebirge, Germany). New species areMurchisonia dornapica, Araeonema osterholzensis, Plagiothyra isekei andMacrochilina drozdzewski. Additionally, a new subspecies,Euryzone delphinuloides oetelshofensis and aNaticopsis-like species and their typical facial occurrence are discussed. The existence of predation is proved by a bore-hole inMacrochilina drozdzewski; the predator itself is not yet identified with certainty.      

放牧方式对浑善达克沙地榆树疏林退化的影响

浑善达克沙地榆树疏林是分布于草原地带的隐域植被类型,相较周边的典型草原区,其植被更加茂密,乔灌丛生,水草丰美,千百年来一直是牧民的优质冬季牧场。近半个世纪以来,因人类的过度开垦以及不合理的放牧管理,浑善达克沙地植被遭到空前的破坏,沙丘活化,载畜能力降低,生态价值和经济价值严重受损。近年来,随着国家草畜平衡以及禁牧政策的推广落实,放牧的牲畜总量得到一定程度的遏制,然而大面积草场还在继续退化。在牧民对生产生活的基本需求下,牲畜总量不可能无限制的压制。另外,适度的放牧对草原生态系统健康是有益的。因此,如何改良放牧方式,合理利用草场,在保持生态良好的基础上合理发挥草场的畜牧价值,是我们亟待探索的问题。以浑善达克沙地的典型天然植被榆树疏林为例,对不同放牧方式下的植被进行调查,基于沙地特殊的基质和植被特征,探讨适合沙地的放牧利用方式。研究表明,在相似的放牧强度下,把沙地作为冬营地,其榆树种群更新正常,植被覆盖度以及植物种类等均能保持良好,而把沙地作为夏季营地,榆树疏林植被退化严重,具体表现为:(1)榆树种群自然更新受阻;(2)灌木群落大量死亡或消失;(3)草本覆盖度显著降低,植物种类减少,多年生草本比例减少,一、二年生草本比例增加;(4)裸沙面积增加,沙丘趋于活化。本研究认为目前沙地植被的退化主要由不合理的放牧引起,并非气候因素所致。沙地适合于冬季放牧而不适合其他季节放牧。借鉴牧民的传统放牧方式,建议配合周边的典型草原区实行季节性倒场放牧,仅将沙地作为冬季营地使用,既能有效保护沙地植被又能充分发挥其畜牧价值。     

Late Ordovician brachiopods from eastern North Greenland: equatorial offshore migration of the Red River fauna

Abstract: Late Ordovician rhynchonelliformean brachiopods, typical of the North American Red River fauna, are found sporadically in the Børglum River Formation of the Centrum Sø area, Kronprins Christian Land, eastern North Greenland. The geographical distribution of this characteristic brachiopod fauna is thus extended to the easternmost extremity of the Laurentian craton. The assemblage compares specifically with the Hiscobeccus brachiopod fauna, based on key taxa such as notably Hiscobeccus gigas (Wang, 1949), and indicates a late Katian age for this part of the succession. For the first time, this typically inland, shallow‐water fauna is found associated with genera like Bimuria, suggesting a transitional marginal facies with outer shelf benthos. The current study describes a Hiscobeccus fauna that lived at the seaward edge of its preferred habitat. Furthermore, an unpublished Hiscobeccus fauna, from the Børglum River Formation of Peary Land, central North Greenland, as well as several occurrences from the Kap Jackson and Cape Calhoun formations in various parts of Washington Land, western North Greenland, are described here. These show a distinct shift from older strata containing H. capax (Conrad, 1842) to younger strata exclusively yielding specimens of H. gigas. As H. gigas occurs in the upper part of the Cape Calhoun Formation in Washington Land, it indicates that the upper boundary of the Cape Calhoun Formation is considerably younger than previous estimates, reaching into the uppermost Katian (middle Cautleyan–Rawtheyan). The Cape Calhoun Formation correlates with the upper member of the Børglum River Formation and further demonstrates that the Hiscobeccus fauna was widespread in Laurentian marginal settings of North Greenland. Even though the Hiscobeccus fauna was pan‐continental during the late Katian (Richmondian), it possesses a strong provincial signal during the later Ordovician. The new occurrences indicate that this fauna extended to the north‐eastern margin of the Laurentian Craton. It lived in close association with cosmopolitan faunal elements that may have been the earliest sign of the succeeding invasion of migrants from Baltica that arrived later during the Hirnantian. The offshore migration of this atypical Hiscobeccus fauna likely demonstrates the path of warm‐water currents as the Centrum Sø locality was located at the equator during the Late Ordovician.     

Arnhemtrachia ramingining: a new genus and species of land snail from Arnhem Land,Australia (Stylommatophora: Camaenidae)

The new, monotypic camaenid genus Arnhemtrachia is described for the new species Arnhemtrachia ramingining from Ramingining, Arnhem Land, Northern Territory, Australia with additional records from the Gove Peninsula in eastern Arnhem Land. This camaenid is characterised by a combination of distinct morphological features, such as a small, discoidal, keeled shell with regular axial ribs, open umbilicus and simple, rounded aperture as well as a reproductive system with a long epiphallus possessing a long flagellum and absence of a penial sheath, with a flap on the penial wall which transverses longitudinal pilasters, and a long, simple bursa copulatrix. Based on comparative morphology, Arnhemtrachia reveals affinities with Trozena morata Iredale, 1838 from NE Queensland.     

Distribution and diving behaviour of crabeater seals (Lobodon carcinophagus) off Queen Maud Land

Eight crabeater seals (Lobodon carcinophagus) (three females, five males), ranging in body mass between 125 and 220 kg, were captured off Queen Maud Land (70–72°S, 7–16°W) during the last week of February, just after moulting, and tagged with Argos satellite-linked dive recorders to provide data on location and diving depth and duration. During the first few weeks of March the seals were moving in the pack ice along the continental shelf edge, close to the coast of Queen Maud Land. In April and May, when the pack ice extended northwards, most of the seals moved north, one reaching 63°S in late May. In the first half of June the two remaining seals turned south and moved back deep into the pack ice. The seals made about 150 dives per day each throughout the study period. Ninety percent of these were made to depths of less than 52 m. Individual maximum diving depths varied between 288 and 528 m. In March the seals were most active at night, when the dive depth was shallower than during the day. In April and May the seals were more active during day-time, with an absence of any diurnal change in divng depth. These results support the notion that crabeater seals predominantly feed on krill in Antarctic pack ice, even when winter returns to the waters off Queen Maud Land.Publication no. 134 of the Norwegian Antarctic Research Expedtion 1992/1993     

Land management affects grass biomass in the Eucalyptus tetrodonta savannas of monsoonal Australia

Abstract We surveyed herbaceous biomass across the range of Eucalyptus tetrodonta savannas in north‐western Australia. Sample sites (n = 211) were stratified within four broad geographical regions characterized by different mixes of land management regimes. Grasses dominated (87% mean) the herbaceous biomass. After controlling for climatic and edaphic gradients, herbaceous biomass was highest in the Greater Darwin region (2.2 t ha⁻¹) which is managed predominantly by Europeans, and least under semi‐traditional Aboriginal management in Arnhem Land region (1.1 t ha⁻¹). In the drier Gulf of Carpentaria and Kimberley regions, where a mix of Aboriginal, conservation and pastoral land uses occurs, fuel loads were higher than in Arnhem Land region but still considerably lower than around Darwin. Sarga was recorded in all regions except the Gulf of Carpentaria and had the highest biomass in Darwin (0.88 t ha⁻¹) and lowest biomass in the Kimberley (0.54 t ha⁻¹). The proportion of herbaceous biomass made up of perennial grasses was least in Darwin (17%) and greatest in the Gulf (77%) regions. We suggest that climate, soils and land management account for differences between the drier pastoral regions of the Gulf of Carpentaria and the Kimberley and the wet Greater Darwin region relative to the Arnhem Land region. The high frequency, and larger spatial scale, of fires in the Greater Darwin region relative to the Arnhem Land region underpins the contrasting trends in total herbaceous biomass and abundance of flammable annual grasses.     

鸢尾属1新变型——白花宽柱鸢尾

描述了鸢尾科鸢尾属宽柱鸢尾(Iris latistyla Y.T.Zhao)的1个新变型——白花宽柱鸢尾(I.latistyla Y.T.Zhao f.albifloraJ.Luo)。原变型的花被为蓝紫色,而新变型花被为白色。并对其潜在的药用研究价值进行了讨论。     

基于功能性状的毛乌素沙地不同演替阶段适生植物筛选

沙地生态系统修复是恢复生态学研究的热点问题,适生植物筛选是修复的关键。植物功能性状反映了植物在不同环境中的生存策略,探究沙地植物功能性状及其与环境之间的关系,有助于筛选用于植被恢复的物种,为保护沙地生态系统提供理论依据。以毛乌素沙地为研究区,分析了1983-2015年间沙地典型飞播样地群落演替特征及其对环境因子的响应,建立基于10个植物功能性状的毛乌素沙地潜在种库,进一步筛选飞播恢复下沙地不同演替阶段的适生植物。研究表明:(1)飞播恢复下的毛乌素沙地植物群落分为三个演替阶段:固沙先锋物种群落、沙生植物为主的杂类草群落、中生植物为主的杂类草群落。(2)土壤因子是群落演替的主要驱动力,其中土壤全氮、土壤总有机碳、土壤硝态氮是影响群落演替的关键因素。(3)基于功能性状筛选出29种适生物种用于植被恢复,演替第一阶段可用雾冰藜、猪毛菜等,演替第二阶段可用拂子茅、无芒隐子草等,演替第三阶段可用草地风毛菊、猪毛蒿等。通过物种功能性状特征可以快速选择适合沙地退化生态系统修复的候选物种,为植被恢复提供了一定的理论支持。     

沙埋与水分对科尔沁沙地主要固沙植物出苗的影响

蒿属半灌木乌丹蒿(Artemisia wudanica)、白沙蒿(A. sphaerocephala)、差不嘎蒿(A. halodendron)是科尔沁沙地的主要固沙植物。其中乌丹蒿和差不嘎蒿是科尔沁沙地的本土植物,白沙蒿为来自于库布齐沙漠、毛乌素沙地的飞播植物。设置了 5个沙埋深度(0.5、1.0、1.5、2.0和3.0 cm)和 4个水分梯度(86、171、257和 342 mL,分别模拟每月25、50、75和100 mm的降雨量),以探讨3种植物幼苗出土对沙埋和水分的响应。结果表明,沙埋与水分均显著影响着3种蒿属植物的幼苗出土(P < 0.001)。3种植物最适沙埋深度在0.5-1.5 cm范围内,萌发出土时适宜水量要高于当地种子萌发期的平均降水量(50 mm/月)。两种固沙先锋植物乌丹蒿和白沙蒿的种子出苗率均显著高于差不嘎蒿,乌丹蒿较白沙蒿也明显为高,尤其在水分缺乏时,表现出两种先锋植物种子出苗对干旱有更好的适应性。协方差分析表明,乌丹蒿幼苗死亡率显著高于白沙蒿和差不嘎蒿(P < 0.05),在达到75 mm/月降水量时,3种植物的出苗较好,但不能满足乌丹蒿幼苗生长对水分的需求,而实际种子萌发期的降水量平均只有50 mm/月。因而降水的缺乏导致乌丹蒿种群更新出现问题,加之飞播植物的竞争,使得近几年科尔沁沙地较多乌丹蒿种群出现衰退。     

An apparent population decrease,or change in distribution,of Weddell seals along the Victoria Land coast

Ground counts during 1959–1968 compared with counts using high resolution (0.6 m²) satellite imagery during 2008–2012 indicated many fewer Weddell seals (Leptonychotes weddellii) at two major molting areas in the western Ross Sea: Edisto Inlet‐Moubray Bay, northern Victoria Land, and McMurdo Sound, southern Victoria Land. Breeding seals have largely disappeared from Edisto‐Moubray, though the breeding population in McMurdo Sound appears to have recovered from harvest in the 1960s. The timing of decline, or perhaps spreading (lower numbers of seals in more places), is unknown but appears unrelated to changes in sea ice conditions. We analyzed both historic and satellite‐derived ice data confirming a large expansion of pack ice mostly offshore of the Ross Sea, and not over the continental shelf (main Weddell seal habitat), and a thinning of fast ice along Victoria Land (conceivably beneficial to seals). Timing of fast ice presence and extent in coves and bays along Victoria Land, remains the same. The reduction in numbers is consistent with an altered food web, the reasons for which are complex. In the context of a recent industrial fishery targeting a seal prey species, a large‐scale seal monitoring program is required to increase understanding of seal population changes.     

New records of Bryum gemmiferum and Atrichum crispum for Turkey

In this study, the bryophyte flora of ??neada Floodplain Forest National Park (K?rklareli-Demirköy) and Acarlar Floodplain Forest (Sakarya-Karasu) in Turkey were investigated in 2016–2017. Here, we report Bryum gemmiferum R. Wilczek & Demaret from ??neada Floodplain Forest National Park in Turkey. In addition, we report Atrichum crispum (James) Sull from both ??neada and Acarlar Floodplain Forest in Turkey. Atrichum crispum is also a new record for Asia continent. Illustrations, location in Turkey and comparisons with morphologically similar taxa were given.     

a new elasmosaurid plesiosaur from the Lower Jurassic of southern France

Plesiosaurus tournemirensis Sciau, Crochet and Mattei, based on a nearly complete skeleton with skull from the Upper Toarcian (Lower Jurassic) of Tournemire (Aveyron Department, southern France), is here redescribed and reinterpreted. Comparisons with other plesiosaurs indicate that it belongs to a new genus, Occitanosaurus . O. tournemirensis is characterized mainly by its spatulate premaxillae with short facial process, very high postorbital broadly contacting posterior ramus of the maxilla, trapezoidal jugal excluded from orbital margin, orbit diagonally oriented, temporal fenestra with a sigmoidal anterior margin, 43 cervical vertebrae, powerful interclavicle-clavicle complex and coracoids with a pointed protuberance on lateral border and expanded posterolateral cornua. Cranial and cervical vertebra features show that this new genus is undoubtedly a representative of the Elasmosauridae. A preliminary cladistic analysis of long-necked plesiosaurs reveals that, within Elasmosauridae, Occitanosaurus is a close relative of Microcleidus and Muraenosaurus .     

Reassessment of the Lower Cretaceous (Barremian) pliosauroid Leptocleidus superstes Andrews, 1922 and other plesiosaur remains from the nonmarine Wealden succession of southern England

The Lower Cretaceous (upper Berriasian to lowermost Aptian) nonmarine Wealden succession of southern England has been a prolific source of vertebrate fossils for over 180 years. The sequence is most famous for terrestrial reptiles, particularly dinosaurs; however, significant aquatic tetrapod discoveries including rare nonmarine plesiosaurs have also been reported. The record of Wealden plesiosaurs currently incorporates a single valid taxon, Leptocleidus superstes Andrews, 1922a, based on a partial skeleton and skull from the Barremian Upper Weald Clay Formation of Berwick, Sussex. Traditional classifications place this plesiomorphic pliosauroid with basal Jurassic rhomaleosaurids; however, the genus Leptocleidus has since become a ‘waste basket’ for various Cretaceous rhomaleosaurid‐like plesiosaurs from around the globe. In an attempt to clarify this situation, the type specimen of L. superstes was reexamined and redescribed. Previously unrecorded anatomical features were identified including an elongate, gracile paraoccipital process on the exoccipital‐opisthotic, and tooth ornament comprising widely spaced, coarse striations that are restricted to the lingual surface of the crown (mesiodistal ‘carinae’ are absent). Other indeterminate pliosauroid remains (recovered along with coeval elasmosaurids) from the upper Berriasian–Valanginian Hastings Beds Group also exhibit potentially diagnostic traits: an atlas centrum with no anterolateral exposure and with ventral margin formed by the intercentrum; a single‐headed rib articulation on the atlas centrum extending onto the axis centrum; and epipodials that are longer than broad. The placement of L. superstes is controversial in recent phylogenies. To test the competing hypotheses, L. superstes together with all closely related species were rescored into the most comprehensive published phylogenetic data sets of Plesiosauria and Pliosauroidea. Separate maximum parsimony and Bayesian analyses of each matrix unanimously supported a relationship between L. superstes and pliosauroids but could not confirm placement within either Rhomaleosauridae sensu stricto, or a discrete ‘leptocleidoid’ clade. Examination of character states advocating affinities amongst Leptocleidus spp. suggests homoplasy rather than clear homology between what are potentially palaeobiogeographically disparate genus‐level taxa. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 663–691.     

Aboriginal Resource Utilization and Fire Management Practice in Western Arnhem Land, Monsoonal Northern Australia: Notes for Prehistory, Lessons for the Future

This paper considers traditional resources and fire management practices of Aboriginal people living in a near-coastal region of western Arnhem Land, monsoonal northern Australia. The data illustrate that before the arrival of Europeans freshwater floodplains and riverine habitats provided the major proportion of food resources over much of the seasonal cycle. By contrast, the extensive lowland woodlands and open forests, the sparser vegetation of the Arnhem Land escarpment and plateau, and the generally small patches of rain forest (jungle), provided relatively few resources, although jungle yams were of critical importance through the relatively lean wet season. The paper then considers burning as a management tool through the seasonal cycle. In broad terms, burning commenced in the early dry season and was applied systematically and purposefully over the landscape. Burning in the late dry season was undertaken with care, and resumed in earnest with the onset of the first storms of the new wet season, particularly on floodplains. These general patterns of resource use and fire management are shown to have applied widely over much of near-coastal northern Australia. The implications of these data for prehistory and for contemporary land management practices in the region, are considered. It is suggested that pre-European patterns of fire management in the region are likely to have been practiced only over the past few thousand years, given the development of abundant food resources in the late Holocene. It is shown that traditional burning practice offers a generally useful, conservative model for living in and managing a highly fire-prone savanna environment.     

Terrestrial vegetation at Canada Glacier,Southern Victoria Land,Antarctica

Summary Bryophyte flushes in the vicinity of Canada Glacier in S.S.S.I. No. 12, Taylor Valley, Southern Victoria Land, were investigated in order to describe the vegetation present and to investigate factors affecting vegetation distribution. Biomass values from 950 to 1,250 g m^–2 (dry weight) and vegetated areas up to 14,450 m² indicate this is a significant area of bryophyte growth in Southern Victoria Land. The pattern of plant species in relation to water flow was investigated through detailed mapping. This is the first confirmed identification of Bryum argenteum, and Pottia heimii, and the first report of Bryum pseudotriquetrum from this area. Tissue nitrogen values for plants at this site are lower than other reported data, but it seems unlikely this would be a limiting factor for growth. It is concluded that, in this area, summer water flow in conjunction with microtopography has the greatest influence in determining where mosses, cyanobacteria and algae grow.     

Growth temperature preferences of fungal strains from Victoria Land,Antarctica

Thirty-five strains of microfungi, isolated from various sites in Victoria Land, Antarctica, were grown at eight temperatures ranging from 0 to 45°C. Only 1 strain (Chaetomium sp. from hot soil) was a thermotolerant mesophile; other strains were psychrophilic (2 strains) or psychrotrophic (32 strains). The fitness of different species to thermal instability is discussed, based on the width of the growth rate curves.     

毛乌素沙地杨柴灌木林恢复演替过程中土壤活性有机碳组分变化特征

土壤活性有机碳是土壤有机碳(SOC)的活性部分,是衡量土壤质量和健康状况的重要指标,能够反映植被恢复演替过程中土壤环境的早期变化。但在SOC贫瘠的沙地,长期恢复演替如何影响土壤活性有机碳组分尚不清楚。本研究以毛乌素沙地杨柴人工灌木林为研究对象,分别选取未造林(CK)与造林年限9 a、18 a和30 a的杨柴人工灌木林,探究毛乌素沙地杨柴人工灌木林恢复演替过程中土壤可溶性有机碳(DOC)、微生物量碳(MBC)、易氧化有机碳(ROC)和SOC变化规律。结果表明：(1)毛乌素沙地杨柴灌木林随恢复演替年限增加土壤固碳能力增强,但在恢复演替18 a时出现转折点,恢复演替18—30 a时土壤固碳速率相对减缓;(2)表层0—10 cm土壤DOC、MBC和ROC对恢复演替响应较为敏感,恢复演替过程中表层土壤活性有机碳各组分含量逐渐升高;(3)恢复演替年限并未对土壤活性有机碳占SOC比例产生显著影响,同时也未显著改变碳库活度。综上所述,毛乌素沙地杨柴灌木林恢复演替有助于土壤活性有机碳和SOC积累,但长期恢复演替是否持续对土壤活性有机碳固持产生积极作用仍需进一步研究。     

砂生槐的一新变型——白花砂生槐

描述了豆科苦参属砂生槐的一个新变型:白花砂生槐[Sophora moorcroftiana(Benth.)Baker f.albiflora S.H.Yang].原变型的花冠为蓝紫色,而新变型的花冠为白色.