首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
Chestnut blight fungus (Endothia parasitica [Murr.] P.J. And. &; H.W. And.)) is a classic example of an invasive species, which severely damaged populations of its host, Castanea dentata, and had widespread and long-term impacts on eastern North American forests. Concurrently, forests were further disturbed by lumbering, which was common across the region from the mid 1800s to the early 1900s. In 1926, local infestations of chestnut blight were reported in the Coweeta Basin, Southern Appalachian Mountains of North Carolina. We used permanent plot inventories of the Basin (first sampled in 1934 and twice afterward in 1969–72 and 1988–93) to describe the distribution of species along a complex environmental gradient. Specifically, we asked: How does vegetation change over approximately 60 years following logging and the demise of C. dentata? Does the association between vegetation and environment determine the pattern of species distributions through time? Which species replaced C. dentata across this complex environmental gradient? We used nonmetric multidimensional scaling ordination and multiresponse permutation procedure for the analyses of the inventory periods. In 1934, C. dentata was the most important species in the Coweeta Basin. It was present in 98% of the plots and contributed 22% of the total density and 36% of the total basal area. Diversity increased significantly over time and was attributed to an increase in evenness of species distribution. The canopy dominant, C. dentata, was replaced by more than one species across the environmental gradient. Importance values of Quercus prinus, Acer rubrum, Cornus florida, Tsuga canadensis, and Oxydendrum arboreum increased by 2–5% across the basin following the decline of C. dentata. Tsuga canadensis increased in abundance and distribution, especially near streams across elevations. Liriodendron tulipifera replaced C. dentata in moist coves, which have low terrain shape and high organic matter content. In contrast, Q. prinus and A. rubrum were ubiquitous, much like C. dentata before the chestnut blight becoming dominant or co-dominant species across all environmental conditions.  相似文献   

2.
3.
The early life stages of Lestidiops sphyraenopsis (Paralepididae) are described on the basis of 14 specimens [7.8 mm in notochord length (NL)–88.6 mm in standard length (SL)] collected from the western North Pacific, and the holotype of Stemonosudis molesta is reexamined. Larval L. sphyraenopsis occurred in the Kuroshio waters, and juveniles were taken in the Kuroshio–Oyashio transition waters. Diagnostic characters of larval and juvenile L. sphyraenopsis are 96–101 myomeres; 27–31 anal fin rays; 4–9 peritoneal pigment sections in larvae (7.8 mm NL–27.3 mm SL); dorsal and anal pigment patches present; and anus located anterior to a vertical through dorsal fin origin. Stemonosudis molesta, known only from the holotype from the South Pacific, is similar to immature specimens of L. sphyraenopsis, but can be clearly distinguished from the latter by having higher vertebral counts (105 vs. 96–101) and by morphometric and pigment differences. Consequently, S. molesta is a valid species, and the distribution of L. sphyraenopsis is restricted to the North Pacific.  相似文献   

4.
对我国菊科橐吾属(Ligularia Cass.) 3种植物原白中模式标本引证的排印错误进行了改正。君范橐吾(L. lingiana S.W. Liu)原白中错误地将主模式标本引证为赵清盛82946,实际应为赵清盛、牟克平和杨亚斌8294。长毛槖吾(L. changiana S.W. Liu ex Y. L. Chen & Z. Yu Li)(=L. heterophylla C. C. Chang,为L. heterophylla Rupr.的晚出同名)主模式为蔡希陶59771,但L. heterophylla C. C. Chang 的原白中错误地将主模式标本引证为蔡希陶59711;该号标本属于唇形科的灯笼草[Clinopodium polycephalum (Vaniot) C. Y. Wu & Hsuan]。南川橐吾(L. nanchuanica S. W. Liu)原白中引证的副模式标本熊济华和周子林93871实际应为李国凤63871,前者属于桤叶树科的城口桤叶树(Clethra fargesii Franch.)。  相似文献   

5.
6.
7.
The wide distribution of the genus Ammosiphonia in the Upper Jurassic and Carboniferous of Western Siberia is established for the first time. Six haplophragmoidid species of Western Siberia are assigned to this genus. The diagnosis of the genus is emended; the taxonomic positions and scopes of the species Ammosiphonia nonioninoides (Reuss), A. beresoviensis (Bulatova), and A. sibirica (Zaspelova) are revised; two new species, A. suprajurassica sp. nov. and A. valanginica sp. nov., are described.  相似文献   

8.
9.
A rare Australian bothid flounder.Asterorhombus bleekeri (Macleay), is redescribed from the holotype and ten additional specimens from the east coast of Qeensland, Gulf of Carpentaria and Rowly Shoal (Western Australia). The species is transferred fromArnoglossus Bleeker toAsterorhombus Tanaka because of the lack of obvious sexual dimorphism in the interorbital width and pectoral fin length, the lack of rostral and orbital spines, the yellow-white blind side body coloration, and the deeply cleft parhypural and hypural plates. The definition ofAsterorhombus was emended as follows: the first dorsal fin ray continuous with or separated from remaining fin rays and gill rakers slender or stubby, with or without serrations.Asterorhombus osculus sp. nov., formerly briefly described in the literature as unidentified species ofEngyprosopon, was described from eight specimens from the northwestern coast of Australia. The new species is most similar toA. bleekeri in lacking sexual dimorphism, and having the caudal skeleton with deep clefts, two or three rows of teeth on the upper jaw and a pair of conspicuous black spots on the caudal fin, in addition to a similar general appearance, but is distinguished from the latter by shorter gill rakers, a very small mouth and feebly ctenoid scales on the ocular side. Both species clearly differed fromA. intermedius andA. fijiensis in having two (or three) rows of teeth on the upper jaws, slender gill rakers without serrations, first dorsal fin ray continuous with the other fin rays, and a pair of conspicuous black spots on the caudal fin.  相似文献   

10.
Symphurus hondoensis Hubbs, 1915, originally described only from the holotype taken in 390–542 m in Suruga Bay Japan, has long been considered a junior synonym ofS. strictus Gilbert, 1905, known from waters off Hawaii, Japan, the Philippine Islands, and South Africa. Based on new information from the holotype and a specimen recently captured from deep waters (789–815 m) off Amami-Oshima Island, southern Japan,S. hondoensis is now established as a valid species.Symphurus hondoensis is unique among congeners in having the combination of a 1–2–3 pattern of interdigitation of proximal dorsal pterygiophores and neural spines, 10 abdominal vertebrae, 14 caudalfin rays, 111–113 dorsal-fin rays, 95 anal-fin rays, 59 total vertebrae, 105–106 scales in longitudinal series, blind side nearly as darkly pigmented as the ocular surface, and a black peritoneum. Recognition ofS. hondoensis increases the number of described species ofSymphurus in waters off Japan to three (S. orientalis Bleeker,S. strictus, andS. hondoensis), with at least one more underscribed species occurring in deepwater hydrothermal vent areas off southern Japan.  相似文献   

11.
12.
The dinocyst genus Montanarocysta Corradini is emended, based on re-examination of the holotype, the paratype and well-preserved specimens of the type species, Montanarocysta aemiliana Corradini. This re-examination shows that M. aemiliana has a sexiform gonyaulacacean tabulation incompletely delineated by processes and septa, a large untabulated ventral area, an apical archeopyle type (tA)a with well-developed precingular accessory sutures, and a simple adnate operculum attached to the sulcal as and precingular plates 1? and 6?. Maghrebinia chleuh Below and Maghrebinia mirabilis (Below) Masure are here transferred to Montanarocysta, since they have closely similar morphology to M. aemiliana. Previously Atopodinium Drugg has been considered as taxonomic senior synonym of Maghrebinia Below and Bejuia Stover Williams, and the species in these two genera have been transferred to Atopodinium. From the present analyses, Atopodinium is separated from Montanarocysta on the ornamentation: Atopodinium has a more subdued ornamentation, consisting of ridges, folds, grana and gemmae; whereas Montanarocysta is characterised by processes and septa. Maghrebinia is herein retained as separate genus, which has a ceratocoryacean tabulation and contains the single species Maghrebinia perforata Below.  相似文献   

13.
The tribe Scotonycterini is currently composed of three fruit bat species of the family Pteropodidae (Mammalia, Chiroptera) characterized by white fur patches on the head, specifically around the nose and behind the eyes: Scotonycteris zenkeri, S. ophiodon and Casinycteris argynnis. Herein a new species is described, Casinycteris campomaanensis sp. nov., based on female specimen collected in 2007 near the village Nkoélon-Mvini close to the Campo-Ma’an National Park, southwestern Cameroon. It is readily distinguished from the three other species of Scotonycterini by its body size and craniodental characteristics. Molecular analyses based on the complete mitochondrial cytochrome b gene indicate that the new species is the sister-group to C. argynnis and that the holotype of S. ophiodon is more closely related to Casinycteris than to S. zenkeri, rendering the genus Scotonycteris paraphyletic. Based on these results, morphological characters within the tribe Scotonycterini were reassessed and a new classification is proposed, in which the new species and S. ophiodon are placed in the genus Casinycteris.  相似文献   

14.
L. A. Santas 《BioControl》1987,32(3):291-297
Four insect species producing honeydew, exploited by bees, were found on wild pear trees,Pyrus amygdaliformis Vill.. Three of them were Psyllids,Cacopsylla (Hepatopsylla) notata (Flor),Cacopsylla (Thamnopsylla) pyrisuga (Förster), Cacopsylla (Hepatopsylla) pyri (L.), and one was Aphid,Dysaphis pyri D.d.F. The 1 rst one was the most abundant. Although these species are producing honeydew from spring to autumn, the bees are foraging on it only during September and October, and not every year. A total of 18 predatory species were counted. Five of them,Anthocoris nemoralis F.,Atractotomus mali Mey.,Chrysoperla carnea (Stephens),Anisochrysa flavifrons (Brauer) andAnisochrysa prasina (Burmeister) were bred in laboratory on the Psyllids. It seems that the predators of theseHomoptera may be able to cause a decrease of their population level. Three predators,Anthocoris nemoralis F.,Chrysoperla carnea (Stephens) andCoccinella septempuctata L., were very common, and the last 2 were present almost all the year round.  相似文献   

15.
New chloranthaceous floral structures from the Late Cretaceous (Late Santonian/Early Campanian) of Scania, southern Sweden, have provided important new information on theChloranthistemon plants. The material includes well preserved fragments of inflorescence axes with flowers in situ documenting thatChloranthistemon flowers were bisexual and closely resembled those of extantChloranthus (Chloranthaceae). An emended diagnosis is given for the type species of the genus,Chloranthistemon endressii, and a new species,C. alatus, is described. The flowers ofChloranthistemon are small, perianthless and strongly zygomorphic, consisting of a tripartite and broadened androecium borne in an abaxial to lateral position on the monocarpellate ovary, and arranged in the axils of decussate bracts. Stamens are either completely free (C. alatus), or free at the base and coherent at the apex (C. endressii). The apical connective is extensive in both species; elaborated into conspicuous wing-like structures inC. alatus, or into a massive and shield-like structure inC. endressii. Pollen grains ofC. endressii are spheroidal, and reticulate and spiraperturate, while those ofC. alatus are ellipsoidal, tectate and foveolate with a unique combination of a distal colpus and a proximal furrow (colpus?) perpendicular to each other. Ovaries observed in well preserved flowers of both species are small and undifferentiated. Larger, dispersed fruits of chloranthaceous affinity are abundant and distinct, and probably represent at least two or three species, but cannot be linked with certainty to any of theChloranthistemon species described here.  相似文献   

16.
A new, insect-associated species of the emended genus Sterigmatomyces, St. wingfieldii, is described. A key to the emended genus is given.  相似文献   

17.
Oleg Pekarsky 《ZooKeys》2013,(351):49-81
The taxa of the Lygephila lusoria (Linnaeus, 1758) species-group are revised. The genital features of all known taxa are described and illustrated with special reference to the structure of vesica. The male genitalia of L. pallida pallida (Bang-Haas, 1907) are described and illustrated for the first time. L. pallida subpicata (Wiltshire, 1971) is treated here as a species, L. pallida subpicata (Wiltshire, 1971), stat. n., distinct from L. pallida. A new species, L. minima, sp. n.,from South Russia is described. Illustrations of the holotype and its genitalia are provided; a diagnostic comparison with L. pallida is given. L. alaica Remm, 1983 is included in the L. lusoria species-group for the first time.  相似文献   

18.
A new aporocotylid blood fluke is described, based on specimens from the ventricle of the Pacific bluefin tuna, Thunnus orientalis (Temminck et Schlegel), cultured in Wakayama and Nagasaki Prefectures, Japan. The new species is morphologically similar to the members of the genus Cardicola Short, 1953, but shows distinct differences in the body form, location of the testis and the orientation of the ootype. The body of the new species is long and slender, whereas other Cardicola species are small and generally lanceolate. The testis is mostly located posterior to the caeca and anterior to the ovary, occupying 31–45% of body length, in contrast to the known Cardicola species, whose testis is typically intercaecal. The ootype is oriented anteriorly, while in most congeners, it is directed posteriorly or horizontally. Phylogenetic analyses of this aporocotylid, together with Cardicola orientalis Ogawa, Tanaka, Sugihara et Takami, 2010 from the same host, were conducted based on DNA sequences of the ITS2 rDNA and the 28S region of ribosomal RNA. The analyses revealed that the new blood fluke belongs to the genus Cardicola despite the marked morphological differences. Thus, this aporocotylid is named Cardicola opisthorchis n. sp. and the generic diagnosis is emended in this paper. In addition, 100% identity among the ITS2 sequences from the present species, Cardicola sp. from T. orientalis in Mexico and Cardicola sp. from the northern bluefin tuna, Thunnus thynnus (Linnaeus) in Spain suggests that C. opisthorchis n. sp. has a broad geographical distribution and that it infects both the Pacific and northern bluefin tuna.  相似文献   

19.
The holotype of Chitinotylenchus paragracilis (Micoletzky, 1922) is redescribed and illustrated. Chitinotylenchus is proposed as a synonym of Ditylenchus Filipjev, 1936 and C. paragracilis as Ditylenchus paragracilis (Micoletzky, 1922) new comb. The four other species in the genus Chitinotylenchus are considered species inquirendae.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号