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 109 毫秒
1.
中国野生牡丹研究 二:芍药属牡丹组新分类群   总被引:13,自引:0,他引:13  
洪涛  奥.  齐鲁 《植物研究》1994,14(3):237-240
本文发表一个新亚种和一个新等级。新亚种林氏牡丹和紫斑牡丹同属一个种系,花瓣基部均具紫斑,花丝,花盘及柱头均为白色;但林氏牡丹的小叶多为披针形或窄卵形,全缘,而紫斑牡丹的小叶多为卵形或卵圆形,常1-3深裂。  相似文献   

2.
Aim We examine the regional dominance of California as a beachhead for marine biological invasions in western North America and assess the relative contribution of different transfer mechanisms to invasions over time. Location Western North America (California to Alaska, excluding Mexico). Methods We undertook extensive analysis of literature and collections records to characterize the invasion history of non‐native species (invertebrates, microalgae and microorganisms) with established populations in coastal marine (tidal) waters of western North America through 2006. Using these data, we estimated (1) the proportion of first regional records of non‐native species that occurred in California and (2) the relative contribution of transfer mechanisms to California invasions (or vector strength) over time. Results Excluding vascular plants and vertebrates, we identified 290 non‐native marine species with established populations in western North America, and 79% had first regional records from California. Many (40–64%) of the non‐native species in adjacent states and provinces were first reported in California, suggesting northward spread. California also drives the increasing regional rate of detected invasions. Of 257 non‐native species established in California, 59% had first regional records in San Francisco Bay; 57% are known from multiple estuaries, suggesting secondary spread; and a majority were attributed to vessels (ballast water or hull fouling) or oysters, in some combination, but their relative contributions are not clear. For California, more than one vector was possible for 56% of species, and the potential contribution of ballast water, hull fouling and live trade increased over time, unlike other vectors. Main conclusions California, especially San Francisco Bay, plays a pivotal role for marine invasion dynamics for western North America, providing an entry point from which many species spread. This pattern is associated historically with high propagule supply and salinity. Any effective strategies to minimize new invasions throughout this region must (1) focus attention on California and (2) address current uncertainty and future shifts in vector strength.  相似文献   

3.
Chandler DS  Caterino MS 《ZooKeys》2011,(147):425-477
The genus Oropodes is characterized and revised with 18 species being treated. Members of this genus are found in temperate forests to desert brush lands from Oregon to Baja California, but are associated primarily with dry forests and shrub lands of California. Keys to males and females, where known, are provided. Seven species are redescribed: Oropodes arcaps (California), Oropodes dybasi (Oregon), Oropodes ishii (California), Oropodes nuclere (California), Oropodes orbiceps (California), Oropodes rumseyensis (California), Oropodes yollabolly (California). The name Oropodes raffrayi (California) is raised from synonymy and the species is redescribed, NEW STATUS. Ten new species are described: Oropodes aalbui (California), Oropodes bellorum (California), Oropodes casson (California), Oropodes chumash (California), Oropodes esselen (California), Oropodes hardyi (California), Oropodes serrano (California), Oropodes tataviam (California), Oropodes tongva (California), and Oropodes tipai (Baja California, Mexico), NEW SPECIES. These species are placed into three species groups: the arcaps-group, the orbiceps-group, and the raffrayi-group. Data for a new record of Euplecterga fideli are given, and a list of the unassociated Oropodes females with distinctive genitalia is included with their label data.  相似文献   

4.
牡丹峰山地暗针叶林大型真菌多样性调查名录   总被引:1,自引:1,他引:0  
2011—2012年对牡丹峰山地暗针叶林带大型真菌资源进行调查和采集,共得到标本130余份,鉴定出大型真菌69种,隶属于3门7纲12目25科39属,其中包括黑龙江省新记录种2种。此外,根据大型真菌获得营养的方式划分出腐生菌类58种,寄生菌类2种,共生菌类9种。  相似文献   

5.
The following ten new species of the ant genus Temnothorax are described and illustrated: T. anaphalantus (California, Baja California), T. arboreus (California), T. caguatan (Oregon, California, Baja California), T. morongo (California, Baja California), T. myrmiciformis (California, Baja California), T. nuwuvi (Nevada), T. paiute (California, Nevada), T. pseudandrei (Arizona, California), T. quasimodo (California) and T. wardi (California). A key to workers of the twenty-two Temnothorax species known or expected to occur in California is provided.  相似文献   

6.
A New, Commercially Valuable Chanterelle Species, Cantharellus californicus sp. nov., Associated with Live Oak in California, USA. The prominent golden chanterelle of California’s oak woodlands is characterized as a new species, Cantharellus californicus sp. nov., using molecular and morphological data. Our observations indicate that it is the largest Cantharellus species in the world, with individual sporocraps commonly weighing 1/2 kilogram (kg) (or 1 pound) or more when mature. Other Cantharellus species in California are compared and evaluated, including their known ectomycorrhizal hosts. The California oak chanterelle is an economically valuable species, and some observations on its commercial harvest are presented.  相似文献   

7.
The "rule" that individuals of nonindigenous plant species are larger where they are introduced than where they are native is not borne out in detailed comparisons of European species introduced to California or the Carolinas and species from California and the Carolinas introduced to Europe. On average, individuals of California species are taller in California than in Europe, while individuals of species native to Europe do not differ between Europe and California. Similarly, individuals of species from the Carolinas are, on average, taller in the Carolinas than in Europe, while individuals of European species are the same height in Europe and the Carolinas or, depending on the nature of the statistical analysis, taller in Europe. Results for herbaceous species only are substantially the same. Although there is no general tendency for species to be taller in their introduced ranges, many species are, in fact, taller in some regions where they are introduced than in their native ranges. Absence of natural enemies in the introduced range is one hypothesis for such observations, but other hypotheses are possible, and the specific reasons for height differences must be sought case by case. The absence of a general tendency casts doubt on the biological control strategy of introducing sequences of phytophages, none of which delivers a knockout blow to a weed, with the expectation that each successive phytophage will force the plant to devote more resources to defense and fewer to traits such as increased size that make it more competitive.  相似文献   

8.
Species of Leucocytozoon (Haemosporida, Leucocytozoidae) traditionally have been described based on morphological characters of their blood stages and host cells, with limited information on their avian host specificity. Based on the current taxonomy, Leucocytozoon toddi is the sole valid species of leucocytozoids parasitizing falconiform birds. Using a nested polymerase chain reaction protocol, we determined the prevalence of Leucocytozoon infection in 5 species of diurnal raptors from California. Of 591 birds tested, 177 (29.9%) were infected with Leucocytozoon toddi. Subsequent phylogenetic analysis of the cytochrome b gene revealed that distinct haplotypes are present in hawks of these genera. Haplotypes present in Buteo spp. are not found in Accipiter spp., and there is a 10.9% sequence divergence between the 2 lineage clades. In addition, Leucocytozoon sp. from Accipiter spp. from Europe group more closely with parasites found in Accipiter spp. from California than the same California Accipiter species do with their sympatric Buteo spp. Similarly, a Leucocytozoon haplotype from a Common Buzzard (Buteo buteo) from Kazakhstan forms a monophyletic lineage with a parasite from B. jamaicensis from California. These results suggest that Leucocytozoon toddi is most likely a group of cryptic species, with 1 species infecting Buteo spp. and 1 or more species, or subspecies, infecting Accipiter spp.  相似文献   

9.
Herbaceous peony, which belongs to sect. Paeonia, Paeonia L., Paeoniaceae, is not only a famous traditional flower in China; it is also highly regarded as an ornamental in Europe and the USA. On account of the abundance in germplasm resources and wide distribution ranges, herbaceous peony can be divided into three cultivar groups, the Chinese Peony Cultivar Group, the European Peony Cultivar Group and the Hybrid Peony Cultivar Group. However, most studies on genetic relationships in Paeonia are limited to the first group. This study used 15 polymorphic microsatellite markers that were developed by magnetic bead enrichment to explore the genetic diversity of 89 genotypes collected from Beijing, the USA and Canada and introduced to China. From 145 allelic loci that were detected from 15 primers, 140 (96.6%) were polymorphic. The number of allelic loci ranged from 4 to 16 with an average of 9.3, and the polymorphic index content ranged from 0.362 to 0.825 with an average of 0.678. Both cluster analysis and principal component analysis based on the 15 polymorphic primer pairs could distinguish the species from cultivars although the cluster analysis was better able to reflect the genetic relationships between all individuals. Some new insights about Paeonia L. are suggested. Furthermore, the 15 SSR markers have great significance as they will allow for furthering the studies on genetic diversity, genetic relationships and even the molecular marker-assisted breeding of Paeonia L.  相似文献   

10.
The anomuran crabs are important from the biogeographic perspective because of their benthonic behavior in their adult state. For this reason, the present work summarizes the different studies developed to date on these crustaceans within the Gulf of California and reinforces the separation of the zone from others in the Province of Cortéz, or Cortesiana. The Gulf of California is inhibited by seventy-eight species of anomurans, belonging to seven families and twenty-eight genera. The best represented family regarding the number of genera (eleven), species (forty-five) and endemic species (eleven) is the Porcellanidae, followed by the Diogenidae with eight genera, fifteen species and four endemic species. The Gulf of California species are distributed in three large zoogeographical groups in the Eastern Pacific, the main one being the Panamic with an intrusion to the Gulf of 69.23% of the species reported. A second important group is that of the endemic species of the Gulf, with 24.35% of the existing species. The boreal species group with intrusion to the Gulf is present with 6.41%. Within the Californian Gulf, ten different zoogeographical groups are found, which demonstrate the great complexity of anomuran distribution, a product of the evolutionary history of this interior sea.  相似文献   

11.
The central California coast is visited by millions of people every year, many of whom collect intertidal gastropods for food, bait or recreation in near-shore marine environments. The harvesting of these animals has caused a decline in body size because humans preferentially take the largest individuals. Marine protected areas (MPAs) may serve to protect gastropods from this impact. The average body size and frequency of four gastropod species from eight study locations along the central California coast were determined. Five study locations were in MPAs and three study locations were in non-MPA zones. Gastropods in four California museums were measured and compared to specimens collected in the field. Three of the four species studied were larger and/or more frequent in MPAs than outside MPAs, including both harvested species and one unharvested species. For three of the four species, the average size of individuals from MPA sites was significantly smaller than museum specimens, but this may be due, in part, to our sampling procedure. These findings indicate that MPAs can be effective at reducing human impacts for some species, but that further study is needed to make MPAs as effective as possible for more species.  相似文献   

12.
Abstract Aims Ants (Hymenoptera: Formicidae) of the Baja California peninsula are poorly known, with information based largely on scattered museum and literature records. We provide the first comprehensive account of ant species occurring on the peninsula, we examine distribution patterns, and we assess the ‘peninsular effect’ which predicts that species richness declines from the base to the tip of a peninsula. Location Peninsula of Baja California, Mexico. Methods Data collection involved examining, identifying and recording label data from c. 2350 series of ants. These records provide a provisional, if incomplete, species list. We applied the incidence‐based estimator, Chao‐2, to our data base of specimen records to estimate the total number of ant species on the peninsula. We assessed endemism by comparing our peninsular species list to those from adjacent states. The peninsular effect was tested by comparing genus and species level richness between the two states of Baja California, and across five latitudinal blocks. Results We document 170 native ant species in thirty‐three genera, plus six non‐native species, in Baja California. It seems likely that additional species remain to be discovered: the Chao‐2 estimator of species richness, at 206.0 species, is about 20% higher than our observed species richness. About 30% of the species and 20% of the genera are restricted within Baja California to the relatively mesic California Floristic Province of north‐western Baja California. Nearly all of these species also occur in California. Forty‐seven species (27.6%) are peninsula endemics. Using our entire data set, the peninsular effect appears to be strong, with about twice as many species in the northern state of Baja California than are recorded from the southern state of Baja California Sur; the ratio of genera is 33 to 24. However, this effect becomes weak at the species level and absent at the genus level when minimizing habitat effects by omitting species restricted to the California Floristic Province. At a finer scale, across latitudinal blocks of about 1.9°, the number of species declines towards central portions of the peninsula and then increases in the Cape Region. Nine ant species display strongly disjunct distributions, and these occur in two general patterns: peninsula disjuncts and peninsula–mainland disjuncts. Main conclusions The Baja California peninsula supports a diverse and distinctive ant fauna, with the proportion of endemic species similar to that displayed by plants. Patterns of species and genus richness across the five latitudinal blocks provide poor support for the peninsular effect. Moreover, habitat diversity, especially that related to topographic relief, appears to be the most important factor affecting the gradient of ant species richness in Baja California. Additional collections are needed to develop a more complete species list and to determine the boundaries and status of many species. Nevertheless, the present data base provides a useful starting point for understanding the evolution of ant assemblages in Baja California and for comparison with peninsular patterns in other taxa.  相似文献   

13.
The California Floristic Province exhibits one of the richest floras on the planet, with more than 5500 native plant species, approximately 40% of which are endemic. Despite its impressive diversity and the attention it has garnered from ecologists and evolutionary biologists, historical causes of species richness and endemism in California remain poorly understood. Using a phylogenetic analysis of 16 angiosperm clades, each containing California natives in addition to species found only outside California, we show that CA's current biodiversity primarily results from low extinction rates, as opposed to elevated speciation or immigration rates. Speciation rates in California were lowest among Arcto‐Tertiary lineages (i.e., those colonizing California from the north, during the Tertiary), but extinction rates were universally low across California native plants of all historical, geographic origins. In contrast to long‐accepted ideas, we find that California diversification rates were generally unaffected by the onset of the Mediterranean climate. However, the Mediterranean climate coincided with immigration of many desert species, validating one previous hypothesis regarding origins of CA's plant diversity. This study implicates topographic complexity and climatic buffering as key, long‐standing features of CA's landscape favoring plant species persistence and diversification, and highlights California as an important refuge under changing climates.  相似文献   

14.
Aim The salamander Ensatina eschscholtzii Gray is a classic example of a ring species, or a species that has expanded around a central barrier to form a secondary contact characterized by species‐level divergence. In the original formulation of the ring species scenario, an explicit biogeographical model was proposed to account for the occurrence of intraspecific sympatry between two subspecies in southern California (the ‘southern closure’ model). Here we develop an alternative ring species model that is informed by the geomorphological development of the California Coast Ranges, and which situates the point of ring closure in the Monterey Bay region of central coastal California (the ‘Monterey closure’ model). Our study has two aims. The first is to use phylogenetic methods to evaluate the two competing biogeographical models. The second is to describe patterns of phylogeographical diversity throughout the range of the Ensatina complex, and to compare these patterns with previously published molecular systematic data. Location Western North America, with a focus on the state of California, USA. Methods We obtained mitochondrial DNA sequence data from 385 individuals from 224 populations. A phylogeny was inferred using Bayesian techniques, and the geographical distributions of haplotypes and clades were mapped. The two biogeographical ring species models were tested against our Bayesian topology, including the associated Bayesian 95% credible set of trees. Results High levels of phylogeographical diversity were revealed, especially in central coastal and northern California. Our Bayesian topology contradicts the Monterey closure model; however, 0.08% of the trees in our Bayesian 95% credible set are consistent with this model. In contrast, the classic ring species biogeographical model (the southern closure model) is consistent with our Bayesian topology, as were 99.92% of the trees in our 95% credible set. Main conclusions Our Bayesian phylogenetic analysis most strongly supports the classic ring species model, modified to accommodate an improved understanding of the complex geomorphological evolution of the California Coast Ranges. In addition, high levels of phylogeographical diversity in central and northern California were identified, which is consistent with the striking levels of allozymic differentiation reported previously from those regions.  相似文献   

15.
The aim of this study was to explore the origin of the invasive Spartina densiflora by analysing samples from the native region (South America) and from a recently colonized area (California). A combination of various molecular data (chloroplast and nuclear sequences, molecular fingerprint) and ploidy level estimations was used to answer the question whether the reticulate phylogenetic pattern previously detected in S. densiflora was restricted to California, or alternatively, whether a more ancient hybrid origin preceded formation of this species in its native area. We found that this species is heptaploid in both its native and introduced range. Identification of nuclear homeologous sequences indicate that this species has a reticulate origin in its native range, involving a lineage related to the hexaploid clade formed by S. alterniflora, S.foliosa, and S. maritima, and another lineage related to the sub-Antarctic endemic S. arundinacea that provided the chloroplast genome. The samples from California displayed similar multilocus patterns to the samples from Chile, supporting the hypothesis that this species originated on the southeast American coast (Argentina), from where it eventually spread to the west coast of South America (Chile) first and to the Northern Hemisphere (California) later.  相似文献   

16.
Collective detection (e.g., enhanced predator detection through the vigilance of conspecifics) is expected to have evolved particularly in social species. However, we assessed the degree to which an avian territorial species (California towhee Pipilo crissalis) would use social cues about predation in a semi-natural assay. We also exposed a social species (house finch Carpodacus mexicanus) to similar conditions. California towhees increased scanning rates when foraging with conspecifics, whereas house finches increased scanning rates when foraging solitarily, suggesting that vigilance in these species is regulated mostly through interference competition and through predation risk, respectively. California towhees did not show early detection, and actually the last detector in the group delayed detection in relation to solitary individuals. House finches benefited from early detection, but the second and last detectors maintained detection at the level of solitary individuals. California towhees increased the chances of fleeing when in groups in relation to solitary conditions, but this effect was less pronounced in the last detector. House finches always fled across conditions. Overall, an asocial avian species may use collective detection, but limited to certain types of cues: responses were more pronounced to overt (conspecifics walking or fleeing) rather than subtle (conspecifics becoming alert or crouching) social cues.  相似文献   

17.
Five species of the genus Phyllodoce from Southern California are reviewed. A new subgenus (Aponaitides) is proposed and a new species, Phyllodoce cuspidata , is described. A key to the Southern California species is included.  相似文献   

18.
Schierenbeck KA  Phipps F 《Genetica》2010,138(11-12):1161-1169
Howellia aquatilis A.Gray (water howellia) is a federally-listed threatened aquatic plant species with limited distribution in four states: California, Idaho, Montana, and Washington. Previous studies have shown a lack of genetic variation within the species; these studies, however, have excluded samples from one or more states. There have been no published studies on the population biology or genetics of the six known California populations or their evolutionary relationship to the other Pacific Northwest populations. We used Amplified Fragment Length Polymorphisms to identify genetic variation within and among the California populations, and to compare the California populations to the Idaho, Montana, and Washington populations. Analysis of molecular variance of 92 individuals from the six California populations show that 83.8% of genetic variation is found within populations and 16.2% among populations (P < 0.001). All sampled populations from all states provide 83.7% variation within and 16.3% variation among populations (P < 0.001). A UPGMA analysis confirms there is no clear clustering of Howellia aquatilis populations within California, that the Montana populations cluster within the California populations, and, although with limited population sample sizes, the Idaho and Washington populations are distantly related to all other populations. Waterfowl migration patterns support a hypothesis for avian dispersal as a primary factor in gene flow in Howellia aquatilis.  相似文献   

19.
Bolton  John J. 《Hydrobiologia》1996,326(1):173-178
Brown algal species diversity is compared in 100 km sections of the coastlines of four warm temperate regions: southern Australia, California, southwestern Africa, north-central Chile. The highest diversity (over 140 species per section) is found in southern Australia. California has a reasonable diversity (around 70 species per section), and both southern Australia and California have high regional endemism. Sections of north-central Chile and southwestern Africa have similar patterns, with low diversity (< 30 species per 100 km section), low endemism, few or no fucoids, and up to 25% of the brown algal flora are environmentally tolerant species of Scytosiphonales. Species turnover between contiguous sections of coast is generally related to relative change in temperature regime. Thus the high diversity of southern Australia is due to high species diversity within the 100 km sections, with little turnover, except for a rapid reduction in eastern Victoria likely to be related to lack of rocky substatum. It is hypothesized that low diversity and endemism in Chile and southwestern Africa can be explained by the occurrence of major environmental perturbations (upwelling and El Nino effects) in these regions, producing variable inter-annual temperature conditions that select out tolerant species from the local floras.  相似文献   

20.
BACKGROUND AND AIMS: Seagrasses are important facilitator species in shallow, soft-bottom marine environments worldwide and, in many places, are threatened by coastal development and eutrophication. One narrow-leaved species (Zostera marina) and one wide-leaved species, variously designated as Z. marina, Z. pacifica or Z. asiatica, are found off the California Channel Islands and adjacent California-Mexico coast. The aim of the present study was to confirm species identification genetically and to link patterns of genetic diversity, connectivity and hybridization among and within the populations with historical sea levels (Ice Age) or the contemporary environment. METHODS: Samples (n = 11-100) were collected from 28 sites off five California Channel Islands and six sites off the adjacent coast of southern California and Baja California, Mexico. DNA polymorphisms of the rDNA-ITS (internal transcribed spacer) cistron (nuclear), the matK intron (chloroplast) and nine microsatellite loci (nuclear) were examined in a population genetic and phylogeographic context. KEY RESULTS: All wide-leaved individuals were Z. pacifica, whereas narrow-leaved forms were Z. marina. Microsatellite genotypes were consistent with hybridization between the two species in three populations. The present distribution of Z. pacifica follows a glacial age land mass rather than present oceanographic regimes, but no link was observed between the present distribution of Z. marina and past or present environments. Island populations of Z. marina often were clonal and characterized by low genotypic diversity compared with populations along the Baja California coast. The high level of clonal connectivity around Santa Catalina Island indicated the importance of dispersal and subsequent re-establishment of vegetative fragments. CONCLUSIONS: The pristine environmental conditions of offshore islands do not guarantee maximum genetic diversity. Future restoration and transplantation efforts of seagrasses must recognize cryptic species and consider the degree of both genetic and genotypic variation in candidate donor populations.  相似文献   

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