西藏蕨类植物新记录

报道了中国西藏自治区蕨类植物新记录2属,即粉叶蕨属(Pityrogramma)和肋毛蕨属(Ctenitis),以及新记录15种1变种——疏叶卷柏(Selaginella remotifolia)、粉叶蕨(Pityrogramma calomelanos)、云南网藤蕨(Lomagramma yunnanensis)、灰绿耳蕨(Polystichum scariosum)、高大复叶耳蕨(Arachniodes gigantea)、兆洪鳞毛蕨(Dryopteris wuzhaohongii)、亮鳞肋毛蕨(Ctenitis subglandulosa)、高山蹄盖蕨(Athyrium silvicola)、卵果双盖蕨(Diplazium ovatum)、肉刺双盖蕨(D.simile)、瘤羽假毛蕨(Pseudocyclosorus tuberculifer)、耳羽钩毛蕨(Cyclogramma auriculata)、尖嘴蕨(Lepisorus mucronatus)、黑鳞瓦韦(L.sordidus)、喙叶假瘤蕨(Selliguea rhynchophylla)和灰茎节肢蕨(Arthromeris himalayensis var.niphoboloides)。该文还对墨脱鳞盖蕨(Microlepia medogensis)的分类学处理提出了新的建议。凭证标本保存在上海辰山植物标本馆(CSH)。     

Brood parasitism by mites (Uropodidae) in an invasive population of the pest-ant Pheidole megacephala

We report that in Okinawa Island (southern Japan) the pupae of the invasive ant Pheidole megacephala were parasitized by an undescribed Uropodidae mite species. Our observations suggest that by sucking the hemolymph of the ant pupae during its own development, mites induce some conspicuous morphological changes and the death of parasitized P. megacephala pupae. Of the 75 collected nests, 69 (92%) were infested by the mite species. The prevalence of parasitism varied strongly among the worker and sexual castes, with the soldier and male pupae being the most attacked, followed by the minor and queen pupae. Our data represent the first case of such high parasitism in an invasive ant population. Received 2 August 2005; revised 29 September 2005; accepted 7 November 2005.     

越南荨麻科楼梯草属和赤车属植物新记录

报道了7个楼梯草属和赤车属植物(荨麻科)新纪录,它们分别为锐齿楼梯草(E. cyrtandrifolium),变黄楼梯草(E. xanthophyllum),对叶楼梯草(E. sinense),宽叶楼梯草(E. platyphyllum),托叶楼梯草(E. nasutum),短叶赤车(P. brevifolia)和华南赤车(P. grijsii)。列出了各个物种的标本引证和地理分布情况。     

Performance of seedlings of the invasive alien tree Schinus molle L. under indigenous and alien host trees in semi-arid savanna

We assessed the importance of host trees in influencing invasion patterns of the alien tree Schinus molle L. ( Anacardiaceae ) in semi-arid savanna in South Africa. Recruitment of S. molle is dependent on trees in its invaded habitat, particularly Acacia tortilis Hayne. Another leguminous tree, the invasive alien mesquite ( Prosopis sp.), has become common in the area recently, but S. molle rarely recruits under canopies of this species. Understanding of the association between these species is needed to predict invasion dynamics in the region. We conducted experiments to test whether: (i) seedling survival of S. molle is better beneath A. tortilis than beneath mesquite canopies; (ii) growth rates of S. molle seedlings are higher beneath A. tortilis than beneath mesquite. Results showed that growth and survival of S. molle did not differ significantly beneath the native A. tortilis and the alien Prosopis species. This suggests that microsites provided by canopies of mesquite are as good for S. molle establishment as those provided by the native acacia. Other factors, such as the failure of propagules to arrive beneath mesquite trees, must be sought to explain the lack of recruitment beneath mesquite.     

Survey for natural enemies of the invasive alien chrysomelid, Diabrotica virgifera virgifera, in Central Europe

The western corn rootworm, Diabrotica virgifera virgifera LeConte(Coleoptera: Chrysomelidae), is the mostdestructive pest of maize (Zea mays L.)in North America, and began to successfullyinvade Central Europe in the early 1990's. Thispaper reports a three-year field surveyconducted in Hungary, Yugoslavia, and Croatia,which are currently the focal points ofinvasion, with the aim to determine theoccurrence of indigenous natural enemies ofD. v. virgifera in Europe. A total of9,900 eggs, 550 larvae, 70 pupae and 33,000adults were examined for the occurrence ofparasitoids, nematodes, and fungal pathogens. It can be concluded from the survey resultsthat effective indigenous natural enemies arenot attacking any of the life stages of D.v. virgifera in Europe. The exception is theoccurrence of the fungi Beauveriabassiana (Bals.) Vuill. (Mitosporic fungi;formerly Deuteromyces) and Metarhiziumanisopliae (Metsch.) Sorok (Mitosporic fungi)attacking adults of D. v. virgifera at anextremely low level (< 1%). However no otherentomopathogenic fungal pathogens,entomopathogenic nematodes, or parasitoids werefound on eggs, larvae, pupae or adults. Whileseveral natural enemies in North and CentralAmerica are known to attack D. v.virgifera, it is apparent that indigenousnatural enemies in Europe have not adapted tothe high population density of the alieninvasive species D. v. virgifera. Classical biological control may provide anopportunity to reconstruct the natural enemycomplex of an invading alien pest, and itsapplication to manage D. v. virgiferapopulations in Europe should be considered.     

New geographical distribution and host records of rust fungi from northern Thailand

Ten species of rust fungi (Crossopsora 2, Maravalia 1, Pileolaria 1, Puccinia 1, Ravenelia 1, Sphaerophragmium 1, Uredo 2, and Uromyces 1) are newly recorded together with six new host plants in Thailand.Contribution no. 194, Laboratory of Plant Parasitic Mycology, Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan     

New records of the carabidicolous laboulbeniales (Ascomycetes) of Japan

Six carabidicolous species of Laboulbeniales are reported as new for the Japanese mycoflora. They areDixomyces stomonaxi, Laboulbenia picardii, L. tenera, L. slackensis, L. aristata andL. kwangjuensis. Two forms ofD. stomonaxi are distinguished, one form of which resemblesD. nigromarginatus. A remarkable ornamentation consisting of a coillike pattern occurs on the receptacle ofL. picardii. InL. tenera andL. slackensis, the outer appendage has somewhat constricted, blackened septa near the base.Laboulbenia aristata andL. kwangjuensis have spirally arranged outer wall cells. Antheridia were observed inL. tenera, L. slackensis, L. aristata andL. kwangjuensis.     

Invasion of alien macroalgae in different Mediterranean habitats

The study evaluated different macroalgal invasions in the main Mediterranean coastal habitats on hard bottom. Biodiversity, species composition and structure of macroalgal assemblages were compared among non-invaded areas and areas invaded by the Chlorophyta Caulerpa racemosa var. cylindracea and by the turf-forming Rhodophyta Womersleyella setacea in three different habitats: shallow rocky bottom, deep rocky bottom and dead matte of the seagrass Posidonia oceanica. Results showed that alien macroalgae constituted a relevant component of benthic assemblages in invaded areas of the Mediterranean Sea. Assemblages invaded by Womersleyella setacea and Caulerpa racemosa showed lower values of diversity and large differences in the structure and species composition related to non-nvaded assemblages. The species that mostly suffered from invasion were erect species reproducing sexually; moreover, the dominance of W. setacea led to low abundance of native filamentous algae, while C. racemosa colonization seemed particularly threatening for encrusting algae. All the studied habitats appeared highly invasible by alien macroalgae, even if W. setacea appeared more invasive in deeper habitats, while colonization of C. racemosa seemed more serious in shallower habitats; the dead matte of P. oceanica represented a suitable substrate for the spread of both species. Differences among assemblages in different habitats were reduced in invaded areas.     

中国石斛属(兰科)植物新资料

在西藏开展兰科植物资源调查过程中,发现了2种石斛属(金石斛组)物种,通过文献和标本的查阅之后,分别确定为麦氏金石斛(Dendrobium macraei Lindl.)和西藏金石斛(D. ritaeanum King & Pantl.),两者均为中国首次记录。其中,麦氏金石斛与流苏金石斛(D. plicatile Lindley)近似,不同之处在于前者唇瓣中裂片边缘全缘,中裂片具2条纵脊,并仅延伸至唇瓣中部,先端凹; 西藏金石斛虽然植株与狭叶金石斛[D. angustifolium (Blume)Lindl.]近似,但该种花很小,萼片和花瓣不具紫色条纹且唇瓣长达1.4 cm,侧裂片三角形,花期时容易区分。同时,该文还提供了该2种石斛属植物详细的形态特征描述以及解剖图版等资料,凭证标本保存于西藏农牧学院标本馆。该发现丰富了中国兰科植物本底资料以及潜在药用植物资源储备,对中国兰科植物的生物多样性研究和药用兰科资源的调查具有重要意义。     

Impact of the invasive alien grass Melinis minutiflora at the savanna-forest ecotone in the Brazilian Cerrado

Exotic grasses are a serious threat to biodiversity in the cerrado savannas of central Brazil. Of particular concern is the possible role they may have in impeding tree regeneration at gallery (riverine) forest edges and increasing fire intensity, thereby driving gallery forest retreat. Here we quantify the effect of roads and distance from gallery forests on the abundance of the African grass Melinis minutiflora Beauv. and test for an effect of this species on woody plant regeneration and leaf area index. Melinis was present at approximately 70% of the sites near gallery forest edges, with its frequency declining sharply at greater distances from the edge. Melinis frequency was 2.8 times greater where roads were present nearby. Leaf area index (LAI) of the ground layer was 38% higher where Melinis was present than where it was absent. LAI was strongly correlated to fine fuel mass (r² = 0.80), indicating higher fuel loads where Melinis was present. The abundance of tree and shrub species in the ground layer was negatively related to LAI and to the presence of Melinis. The greater fuel accumulation and reduced tree regeneration caused by Melinis may cause a net reduction in forest area by increasing fire intensity at the gallery forest edge and slowing the rate of forest expansion.     

New species and records of saprophytic ascomycetes (Myxotrichaceae) from decaying logs in the boreal forest

Decayed wood from fallen white spruce (Picea glauca) and trembling aspen (Populus tremuloides) collected in northeastern Alberta, Canada, was the source of new isolates of species in the ascomycete generaGymnostellatospora andPseudogymnoascus. In addition to new reports ofG. japonica, G. frigida andP. roseus, two new species are described.Gymnostellatospora canadensis sp. nov. resemblesG. japonica but differs in producing brown ascomata and in the formation of an arthroconidial anamorph.Gymnostellatospora subnuda sp. nov. is distinct in lacking differentiated peridial hyphae.Gymnostellatospora alpina was not found in decayed wood but is reviewed based on extralimital material. A dichtomous key to the five species ofGymnostellatospora is provided.     

New records of minute litter-decomposing basidiomycetes from Japan.Actiniceps thwaitesii (Pterulaceae) new to Japan andAnastrophella podocarpicola sp. nov. (Tricholomataceae)

Actiniceps thwaitesii (Pterulaceae) new to Japan andAnastrophella podocarpicola sp. nov. (Tricholomataceae) are described and illustrated. The former is characterized by forming stipitate-capitate basidiomata under 1 mm tall with encrusted cystidia and acanthophyses. The latter, occurring on a decaying leaf ofPodocarpus macrophyllus, differs from other taxa ofAnastrophella in having undifferentiated hymenial cystidia and smaller basidiospores and basidia. Their cultural features are also presented.     

Shifts in aquatic macroinvertebrate biodiversity associated with the presence and size of an alien crayfish

To investigate the effects of Procambarus clarkii on macroinvertebrate diversity, we conducted a mesocosm experiment simulating small pools in rice field pads after the rice season. We hypothesized that crayfish predation would negatively impact macroinvertebrate diversity, and the magnitude of this impact should vary with the size of P. clarkii. We conducted a short-term mesocosm experiment to determine macroinvertebrate diversity in the presence of three size classes and in the absence of crayfish, as well as the diet composition of crayfish from the three size classes. At the end of the experiments, the diet of crayfish was composed of the most available taxa (Culicidae, Chironomus, Tanytarsini and Orthocladinae). These results also show evidence that, in confined areas, crayfish are important predators of major rice pests such as rice Chironominae larvae. Macroinvertebrate diversity was negatively affected by crayfish presence, but the effect was inversely proportional to crayfish size. The highest diversity index was obtained in the absence of P. clarkii, and juvenile crayfish significantly reduced macroinvertebrate diversity. Thus, the impact of P. clarkii on aquatic macroinvertebrates is size dependent and may be relevant in small pools formed in rice field pads from early autumn to late winter. Overall, our findings suggest that the negative effects of P. clarkii on macroinvertebrate diversity may be particularly strong in local natural assemblages confined to puddles of water or small ponds in wetland areas.     

Ecological and morphological differentiation of pumpkinseed sunfish in lakes without bluegill sunfish

Summary Over the last three decades, sunfish of the familyCentrarchidae have become recognized as a model system in which the ecological consequences of species interactions can be observed and tested. The evolutionary consequences of species interactions in sunfish have received less attention. Bluegill (Lepomis machrochirus) and pumpkinseed (Lepomis gibbosus) sunfish are two common and well-studied species that occupy separate ecological niches. Adult bluegill are generalists that feed in the open water on zooplankton during much of the year, while adult pumpkinseeds specialize on crushing hard-bodied prey such as snails. These species coexist over much of their geographical ranges, but bluegill are historically absent from several large drainage basins in the northeastern US. Here we show that pumpkinseeds from an Adirondack lake without bluegills have differentiated into two morphological forms, one of which is planktivorous. Differentiation is independent of sex and occurs over a broad range of sizes. Thus, the ecological diversity that exists between the bluegill and pumpkinseeds in sympatry has been replaced by a comparable degree of diversity within pumpkinseeds in allopatry.     

New records of deep-sea fishes from the waters around the Falkland Islands

The manefish Caristius groenlandicus , the spiny eel Notacanthus sexspinis , the cutthroat eel Diastobranchus capensis and the Giant Grenadier Albatrossia pectoralis are new records for the waters of the Falkland Islands, and the latter is a new record in the Atlantic Ocean.     

Influence of settlement time, human population, park shape and age, visitation and roads on the number of alien plant species in protected areas in the USA

Abstract. I examined a data set of 77 protected areas in the USA (including national and state parks) to determine which of the following variables most strongly influence alien plant species richness: park area, climate (temperature and precipitation), native species richness, visitation rate, local human population size, total road length, park shape and duration of European settlement. Many of these predictor variables are intercorrelated, so I used multiple regression to help separate their effects. In support of previous studies, native species richness was the best single predictor of alien species richness, probably because it was a good estimator of both park area and habitat diversity available for establishment of alien species. Other significant predictors of alien species richness were years of occupation of the area by European settlers and the human population size of adjacent counties. Climate, visitation rate, road length and park shape did not influence alien species richness. The proportion of alien species (alien richness/native richness) is inversely related to park area, in agreement with a previous study. By identifying which variables are most important in determining alien species richness, such findings suggest ways to reduce alien species establishment.     

Developing a list of invasive alien species likely to threaten biodiversity and ecosystems in the European Union

The European Union (EU) has recently published its first list of invasive alien species (IAS) of EU concern to which current legislation must apply. The list comprises species known to pose great threats to biodiversity and needs to be maintained and updated. Horizon scanning is seen as critical to identify the most threatening potential IAS that do not yet occur in Europe to be subsequently risk assessed for future listing. Accordingly, we present a systematic consensus horizon scanning procedure to derive a ranked list of potential IAS likely to arrive, establish, spread and have an impact on biodiversity in the region over the next decade. The approach is unique in the continental scale examined, the breadth of taxonomic groups and environments considered, and the methods and data sources used. International experts were brought together to address five broad thematic groups of potential IAS. For each thematic group the experts first independently assembled lists of potential IAS not yet established in the EU but potentially threatening biodiversity if introduced. Experts were asked to score the species within their thematic group for their separate likelihoods of i) arrival, ii) establishment, iii) spread, and iv) magnitude of the potential negative impact on biodiversity within the EU. Experts then convened for a 2‐day workshop applying consensus methods to compile a ranked list of potential IAS. From an initial working list of 329 species, a list of 66 species not yet established in the EU that were considered to be very high (8 species), high (40 species) or medium (18 species) risk species was derived. Here, we present these species highlighting the potential negative impacts and the most likely biogeographic regions to be affected by these potential IAS.