Origin,Differentiation, and Geographic Distribution of the Chenopodiaceae

Numbers of species and genera,endemic genera,extant primitive genera,relationship and distribution patterns of presently living Chenopodiaceae(two subfamilies,12 tribes,and 118 genera)are analyzed and compared for eight distributional areas,namely central Asia,Europe,the Mediterranean region,Africa,North America,South America, Australia and East Asia． The Central Asia,where the number of genera and diversity of taxa are greater than in other areas,appears to be the center of distribution of extant Chenopodiaceae．North America and Australia are two secondary centers of distribution． Eurasia has 11 tribes out of the 12,a total of 70 genera of extant chenopodiaceous plants,and it contains the most primitive genera of every tribe． Archiatriplex of Atripliceae,Hablitzia of Hablitzeae,Corispermum of Corispermeae,Camphorosma of Camphorosmaea,Kalidium of Salicornieae,Polecnemum of Polycnemeae,Alexandra of Suaedeae,and Nanophyton of Salsoleae,are all found in Eurasia,The Beteae is an Eurasian endemic tribe,demonstrating the antiquity of the Chenopodiaceae flora of Eurasia．Hence,Eurasia is likely the place of origin of chenopodiaceous plants． The presence of chenopodiaceous plants is correlated with an arid climate．During the Cretaceous Period,most places of the continent of Eurasia were occupied by the ancient precursor to the Mediterranean,the Tethys Sea．At that time the area of the Tethys Sea had a dry and warm climate．Therefore,primitive Chenopodiaceae were likely present on the beaches of this ancient land．This arid climatic condition resulted in differentiation of the tribes Chenopodieae,Atripliceae,Comphorosmeae,Salicornieae,etc．,the main primitive tribes of the subfamily Cyclolobeae. Then following continental drift and the Laurasian and Gondwanan disintegration, the Chenopodiaceae were brought to every continent to propagate and develop, and experience the vicissitudes of climates, forming the main characteristics and distribution patterns of recent continental floras. The tribes Atripliceae, Chenopodieae, Camphorosmeae, and Salicornieae of recent Chenopodiaceae in Eurasia, North America, South America, southern Africa, and Australia all became strongly differentiated. However, Australia and South America, have no genera of Spirolobeae except for a few maritime Suaeda species. The Salsoleae and Suaedeae have not arrived in Australia and South America, which indicates that the subfamily Spirolobeae developed in Eurasia after Australia separated from the ancient South America-Africa continent, and South America had left Africa. The endemic tribe of North America, the tribe Sarcobateae, has a origin different from the tribes Salsoleae and Suaedeae of the subfamily Spirolobeae. Sarcobateae flowers diverged into unisexuality and absence of bractlets. Clearly they originated in North America after North America had left the Eurasian continent. North America and southern Africa have a few species of Salsola, but none of them have become very much differentiated or developed, so they must have arrived through overland migration across ancient continental connections. India has no southern African Chenopodiaceae floristic components except for a few maritime taxa, which shows that when the Indian subcontinent left Africa in the Triassic period, the Chenopodiaceae had not yet developed in Africa. Therefore, the early Cretaceous Period about 120 million years ago, when the ancient Gondwanan and Laurasian continents disintegrated, could have been the time of origin of Chenopodiaceae plants.The Chinese flora of Chenopodiaceae is a part of Chenopodiaceae flora of central Asia. Cornulaca alaschnica was discovered from Gansu, China, showing that the Chinese Chenopodiaceae flora certainly has contact with the Mediterranean Chenopodiaceae flora. The contact of southeastern China with the Australia Chenopodiaceae flora, however, is very weak.     

藜科植物的起源、分化和地理分布

全球藜科植物共约130属1500余种,广泛分布于欧亚大陆、南北美洲、非洲和大洋洲的半干旱及盐碱地区。它基本上是一个温带科,对亚热带和寒温带也有一定的适应性。本文分析了该科包含的1l族的系统位置和分布式样,以及各个属的分布区,提出中亚区是现存藜科植物的分布中心,原始的藜科植物在古地中海的东岸即华夏陆台(或中国的西南部)发生,然后向干旱的古地中海沿岸迁移、分化,产生了环胚亚科主要族的原始类群;起源的时间可能在白垩纪初,冈瓦纳古陆和劳亚古陆进一步解体的时期。文章对其迁移途径及现代分布式样形成的原因进行了讨论。     

中国柳属多雄蕊类群的分支系统学研究

应用杨属(Populus)和钻天柳属(Chosenia)分别作为不同的外类群,对中国柳属多雄蕊类群构建了两个分支图。结果表明,钻天柳属、大叶柳和四子柳组(Sect.Tetraspermae)都是较原始的类群。支持建立Toisusu Kimura属。根据分支图和染色体数目资料,多雄蕊类群可划分五个类组。支持方振富教授关于"南方型"和"北方型"的划分以及在东亚有从南方向北方演化的趋势,特别对于中国特有组紫柳组(Sect.Wilsonianae).Sect.Salix和Sect.Subalbae两组的分化应予以承认。     

The Origin,Dispersal and Formation of the Distribution Pattern of Swertia L. (Gentianaceae)

The genus Swertia is one of the large genera in Gentianaceae, including 154 species, 16 series and 11 sections. It is disjunctly distributed in Europe, Asia, Africa and N. America, but entirely absent from Oceania and S. America. According to Takhtajan’s (1978) regionalization of the world flora, Swertia is found in 14 regions. Eastern Asiatic region with 86 species, of which 58 are local endemics, 13 series and 9 sections, ranks the first among all the regions. The highest concentration of the taxa and endemics in Eastern Asiatic region occurs in SW China-Himalayan area (Sikang-Yunnan P. , W. Sichuan, W. Yunnan-Guichou Plateau of China and NE. Burma, N. Burmense P. , E. Himalayan P. and Khasi-Manipur P. ). In this area there are 74 species (48 endemics), 12 series, and 9 sections; thus about half species of the world total, three quarters of series and 82% of sections occur in this small area. Besides, the taxa at different evolutionary stages in Swertia also survive here. It is an indication that SW. China-Himalayan area is a major distribution centre of the genus Swertia. In addition, Sudan-Zambezian Region in Africa, with 22 species, 4 series and 2 sections, is a second distribution centre. The primitive type of the genus Swertia is Sect. Rugosa which consists of 2 series and 23 species. It is highly centred in the mountains of SW. China (Yunnan, Sichuan, Guizhou and SE. Xizang) where 2 series and 16 species occur. Among them 15 species of Ser. Rugosae were considered as the most primitive groups in this genus. From our study, the outgroup of Swertia is the genus Latouchea Frahch. , which is distributed in Yunnan, Sichuan, Guizhou, Hunan, Guangdong, Guangxi and Fujian. The two groups overlap in distribution in SW. China. According to the principle of common origin, the ancestor of two genera ap peared most probably in this overlapping area. It was inferred that SW. China Was the birth-place of the genus Swertia. Four sections of Swertia have different disjunct distribution patterns: Sect. Ophelia is of Tropic Asia, Africa and Madagascar disjunct distribution; sect. Swertia is of north temperate distribution; sect. Spinosisemina is in Tropical Asia (Trop. India to S. China and Philipines); sect. Platynema also is in Tropical Asia (Java, Sumatra, Himalayas to SW. China). These disjunct patterns indicate that the Swertia floras between the continents or between continent and islands have a connection with each other. From paleogeographical analysis, Swertia plants dispersed to Madagascar before the Late Cretaceous, to SE. Asian Islands in the Pleistocene, to North America in the Miocene. The distribution of Swertia in Madagascar might be later than that in Asia. Therefore the origin time of the genus Swertia was at least not later than the Late Cretaceous, and might be back to the Mid-Cretaceous. The genus Swertia first fully developed and differentiated, forming some taxa at different evolutionary stages (Rugosa, Swertia, Poephila, Ophelia and Platynema etc. ) in the original area, and these taxa quickly dispersed in certain directions during the Late Cretaceous-Middle Tertiary when the global climate was warm and no much change. There seem to be three main dispersal routes from the origin area to different continents; (1) The westward route i. e. from SW. China, along the Himalayas area to Kashmir, Pakistan, Afghanistan and Iran, and then southwestwards into Africa throuth Arabia. Four sections (Poephila, Macranthos, Kingdon-Wardia and Ophelia) took this dispersal route. Most species of sect. Ophelia dispersed along this route, but a few along southern route and north ern route. Sect. Ophelia greatly differentiated in Africa and the African endemic sectionSect. Montana was derived from it. The two sections form there a second distribution center of Swertia. (2) The southward route, i. e. towards S. India through the Himalayas, and towards SE. Asian islands through C. and S. China, Indo-China. Along this dispersal route sect. Platynema, Sect. Spinosisemina and a few species of Sect. Ophelia dispersed; (3) The northward rout, i. e. northwards across N. China, C. Asia to a high latitude of Euasia, and also through E. Asia into N. America. The following groups took this route: sect. Rugosa, sect. Swertia, sect. Frasera, sect. Heteranthos and sect. Ophelia ser. Dichotomae. Therefore, it seems that the genus Swertia originated in SW. China and then dispersed from there to N. and S. Asia, Africa, Europe and North America and formed the moderndistribution pattern of this genus.     

On the geographical distribution of the Juglandaceae

The present paper aims to discuss the geog raphical distribution of the Juglandaceae on the basis of unity of the phylogeny and the process of dispersal in the plants. The paper is divided into the following three parts: 1. The systematic positions and the distribution patterns of nine living genera in the family Juglandaceae (namely, Engelhardia, Oreomunnea, Alfaroa, Pterocarya, Cyclocarya, Juglans, Carya, Annamocarya and Platycarya) are briefly discussed. The evolutional relationships between the different genera of the Juglandaceae are elucidated. The fossil distribution and the geological date of the plant groups are reviewed. Through the analysis for the geographical distribution of the Juglandaceous genera, the distribution patterns may be divided as follows: A. The tropical distribution pattern a. The genera of tropical Asia distribution: Engelhardia, Annamocarya. b. The genera of tropical Central America distribution: Oreomunnea, Alfaroa. B. The temperate distribution pattern c. The genus of disjunct distribution between Western Asia and Eastern Asia: Pterocarya. d. The genus of disjunct distribution between Eurasia and America: Juglans. e. The genus of disjunct distribution between Eastern Asia and North America: Carya. f. The genera whose distribution is confined to Eastern Asia: Cyclocarya, Platycarya. 2. The distribution of species According to Takhtajan’s view point of phytochoria, the number of species in every region are counted. It has shown clearily that the Eastern Asian Region and the Cotinental South-east Asian Region are most abundant in number of genera and species. Of the 71 living species, 53 are regional endemic elements, namely 74.6% of the total species. The author is of the opinion that most endemic species in Eurasia are of old endemic nature and in America of new endimic nature. There are now 7 genera and 28 species in China, whose south-western and central parts are most abundant in species, with Province Yunnan being richest in genera and species. 3. Discussions of the distribution patterns of the Juglandaceae A. The centre of floristic region B. The centre of floristic regions is determined by the following two principles: a. A large number of species concentrate in a district, namely the centre of the majority; b. Species of a district can reflect the main stages of the systematic evolution of the Juglandaceae, namely the centre of diversity. It has shown clearly that the southern part of Eastern Asian region and the northern part of Continental South-east Asian Region (i.c. Southern China and Northern Indo-China) are the main distribution centre of the Juglandaceae, while the southern part of Sonora Region and Caribbean Region (i.c. South-western U.S.A., Mexico and Central America) are the secondary distribution centre. As far as fossil records goes, it has shown that in Tertiary period the Juglandaceae were widely distributed in northern Eurasia and North America, growing not only in Europe and the Caucasus but also as far as in Greenland and Alaska. It may be considered that the Juglandaceae might be originated from Laurasia. According to the analysis of distribution pattern for living primitive genus, for example, Engelhardia, South-western China and Northern Indo-China may be the birthplace of the most primitive Juglandaceous plants. It also can be seen that the primitive genera and the primitive sections of every genus in the Juglandaceae have mostly distributed in the tropics or subtropics. At the same time, according to the analysis of morphological characters, such as naked buds in the primitive taxa of this family, it is considered that this character has relationship with the living conditions of their ancestors. All the evidence seems to show that the Juglandaceae are of forest origin in the tropical mountains having seasonal drying period. B. The time of the origin The geological times of fossil records are analyzed. It is concluded that the origin of the Juglandaceae dates back at least as early as the Cretaceous period. C. The routes of despersal After the emergence of the Juglandaceous plant on earth, it had first developed and dispersed in Southern China and Indo-China. Under conditions of the stable temperature and humidity in North Hemisphere during the period of its origin and development, the Juglandaceous plants had rapidly developed and distributed in Eurasia and dispersed to North America by two routes: Europe-Greenland-North America route and Asia-Bering Land-bridge-North America route. From Central America it later reached South America. D. The formaation of the modern distribution pattern and reasons for this formation. According to the fossil records, the formation of two disjunct areas was not due to the origin of synchronous development, nor to the parallel evolution in the two continents of Eurasia and America, nor can it be interpreted as due to result of transmissive function. The modern distribution pattern has developed as a result of the tectonic movement and of the climatic change after the Tertiary period. Because of the continental drift, the Eurasian Continent was separated from the North American Continent, it had formed a disjunction between Eurasia and North America. Especially, under the glaciation during the Late Tertiary and Quaternary Periods, the continents in Eurasia and North America were covered by ice sheet with the exception of “plant refuges”, most plants in the area were destroyed, but the southern part of Eastern Asia remained practically intact and most of the plants including the Juglandaceae were preserved from destruction by ice and thence became a main centre of survival in the North Hemisphere, likewise, there is another centre of survival in the same latitude in North America and Central America. E. Finally, the probable evolutionary relationships of the genera of the Juglanda-ceae is presented by the dendrogram in the text.     

A NEW MICROCHOERINE OMOMYID (PRIMATES, MAMMALIA) FROM THE ENGLISH EARLY EOCENE AND ITS PALAEOBIOGEOGRAPHICAL IMPLICATIONS

Abstract:  A new genus and species of omomyid primate, Melaneremia bryanti , is described from the Early Eocene Blackheath Beds of Abbey Wood, London, UK. It shares unique derived characters with the European subfamily Microchoerinae and is its most primitive member. It is nevertheless more derived than the primitive omomyid Teilhardina belgica from the beginning of the European Eocene. Cladistic analysis shows that the Microchoerinae are sister group to a clade comprising subfamilies Omomyinae and Anaptomorphinae, but excluding Teilhardina belgica and T. asiatica , which are stem omomyids. The Mammalian Dispersal Event (MDE), which marks the beginning of the Eocene (55·8 Ma), saw the dispersal of primates, perissodactyls and artiodactyls into the Northern Hemisphere. At this time similar species of Teilhardina lived in Europe, Asia and North America. The Abbey Wood microchoerine lived about 1 million years later. It co-occurs with non-primate species identical or very similar to those that lived in North America. The latter were ground-dwellers, whereas the microchoerine and others that show distinct differences from North American relatives were tree-dwellers. Land-bridges connected North America and Europe via Greenland at the beginning of the Eocene, but 2 million years later these had been severed by submarine rifting. North American species at Abbey Wood indicate that a land connection still remained at c . 55 Ma. However, the forest belt that must have been continuous during the MDE to allow tree-dwellers to disperse between the continents is likely by this time to have been disrupted, perhaps by volcanic eruption.     

杨亚科植物的分类与分布

杨亚科（Populoideae）植物自然分布于热带非洲和大约从北纬19°～70°度的北半球,由胡杨属（Balsamiflua）和杨属（Populus）2个属所组成。胡杨属间断分布于赤道非洲、古地中海地区和墨西哥,包含2个组（胡杨组、墨杨组）和约3个天然种。杨属分布于欧洲、亚洲、非洲（北缘）和北美洲的广大地区,包含大叶杨亚属（Subgen．Leucoides）（大叶杨组）、杨亚属（Subgen．Populus）（青杨组、黑杨组、杨组）2个亚属和约52个天然种。拟定了杨亚科属的检索表、胡杨属组和种的检索表、杨属亚属和组的检索表以及杨属中各组种的检索表。提供了一个杨树种类目录,包括它们的正名、异名、文献引注和地理分布等。     

Molecular phylogeny and historical biogeography of the Holarctic wetland leaf beetle of the genus Plateumaris

Leaf beetles of the genus Plateumaris inhabit wetlands across the temperate zone of the Holarctic region. To explore the phylogeographic relationships among North American, East Asian, and European members of this genus and the origin of the species endemic to Japan, we studied the molecular phylogeny of 20 of the 27 species in this genus using partial sequences of mitochondrial cytochrome oxidase subunit I (COI) and the 16S and nuclear 28S rRNA genes. The molecular phylogeny revealed that three species endemic to Europe are monophyletic and sister to the remaining 11 North American and six Asian species. Within the latter clade, North American and Asian species did not show reciprocal monophyly. Dispersal-vicariance analysis and divergence time estimation revealed that the European and North America-Asian lineages diverged during the Eocene. Moreover, subsequent differentiation occurred repeatedly between North American and Asian species, which was facilitated by three dispersal events from North America to Asia and one in the opposite direction during the late Eocene through the late Miocene. Two Japanese endemics originated from different divergence events; one differentiated from the mainland lineage after differentiation from the North American lineage, whereas the other showed a deep coalescence from the North American lineage with no present-day sister species on the East Asian mainland. This study of extant insects provides molecular phylogenetic evidence for ancient vicariance between Europe and East Asia-North America, and for more recent (but pre-Pleistocene) faunal exchanges between East Asia and North America.     

A Review of the Fossil Record of the Genus Itea (Iteaceae, Saxifragales) with Comments on its Historical Biogeography

Itea is a genus of about 20 species of trees and shrubs that are today native to southeastern North America, eastern Asia, and eastern Africa. In this paper, I review the fossil record of Itea, which is based on four types of fossils: diporate, psilate pollen attributed to Itea or the dispersed pollen genus Iteapollis; carpofossils representing fruits and seeds attributed to Itea europaea; flowers preserved in amber and assigned to Adenanthemum iteoides; and leaf impressions attributed to Itea. The distributions of these fossils indicate that Itea was present in western North America from the early Eocene to Miocene, in eastern North America beginning no later than the early Miocene, and in western Eurasia from the late Eocene to Pliocene. Only one datapoint is known from eastern Asia; it is early Miocene in age. Based on the fossil record, it can be inferred that Itea crossed between continents over both the Bering Land Bridge and North American Land Bridge, and that it reached Africa from Europe via Anatolia. Thus, it is predicted that the sole extant North American species, I. virginica, may be most closely related to the sole extant African species, I. rhamnoides. The potential application of Itea fossils to calibrating phylogenetic trees generated from molecular sequence data is also discussed.     

木兰科的化石记录

通过整理和分析木兰科植物的化石记录发现：不论是植物大化石还是花粉,迄今为止在白垩纪以前地层中尚无可靠的记录,自白垩纪以来,木兰科的许多种广泛发生于北半球,如亚洲,欧洲及北美等地,但非洲和大洋洲至今尚未发现木兰科的化石记录。该科最早的化石记录为中国东北延吉地区早白垩世大拉子组的喙柱始木兰Archimagnolia rostrato-stylose Tao et Zhang. 根据现有化石记录,并结合木兰科现代植物的地理分布,推测：1）木兰科的起源时间不迟于早白垩世Aptian-Albian期;2）木兰科起源地点可能是东亚,后来经过欧洲进入北美,再从北美迁移到达南美洲;3）在地质历史时期,木兰属的出现比鹅掌楸属早,从而支持根据形态学与分子系统学研究得出的木兰属较鹅掌楸属原始的结论。     

Epizootic ulcerative syndrome (EUS) in fish: history and current status of understanding

Epizootic ulcerative syndrome (EUS) is one of the most important diseases affecting more than 100 species of wild and cultured finfish. EUS was first reported in farmed ayu (Plecoglossus altivelis) from Japan in 1971 and has since then spread across different countries of four continents including Asia, Australia, North America and Africa. The spread of the disease, especially in Asia–Pacific region and Africa has led to substantial damage to the fish resources and livelihood of the fish farmers. No reports are available confirming the outbreak of the disease from Europe and South America. The latest outbreak of EUS has been reported from Canada in a new susceptible species brown bullhead, Ameiurus nebulosus. It seems that the disease has potential to spread further, owing to the epizootic nature of the disease and broad susceptible host range. Considering the global importance of this disease, this review provides the current status of understanding about the etiology, process of diseases development, species affected, diagnostic methods as well as control and preventive measures, in light of the historical developments in those areas.     

Extended phylogeny of Aquilegia: the biogeographical and ecological patterns of two simultaneous but contrasting radiations

Studies of the North American columbines (Aquilegia, Ranunculaceae) have supported the view that adaptive radiations in animal-pollinated plants proceed through pollinator specialisation and floral differentiation. However, although the diversity of pollinators and floral morphology is much lower in Europe and Asia than in North America, the number of columbine species is similar in the three continents. This supports the hypothesis that habitat and pollinator specialisation have contributed differently to the radiation of columbines in different continents. To establish the basic background to test this hypothesis, we expanded the molecular phylogeny of the genus to include a representative set of species from each continent. Our results suggest that the diversity of the genus is the result of two independent events of radiation, one involving Asiatic and North American species and the other involving Asiatic and European species. The ancestors of both lineages probably occupied the mountains of south-central Siberia. North American and European columbines are monophyletic within their respective lineages. The genus originated between 6.18 and 6.57 million years (Myr) ago, with the main pulses of diversification starting around 3 Myr ago both in Europe (1.25–3.96 Myr ago) and North America (1.42–5.01 Myr ago). The type of habitat occupied shifted more often in the Euroasiatic lineage, while pollination vectors shifted more often in the Asiatic-North American lineage. Moreover, while allopatric speciation predominated in the European lineage, sympatric speciation acted in the North American one. In conclusion, the radiation of columbines in Europe and North America involved similar rates of diversification and took place simultaneously and independently. However, the ecological drivers of radiation were different: geographic isolation and shifts in habitat use were more important in Europe while reproductive isolation linked to shifts in pollinator specialisation additionally acted in North America.     

杨亚科植物的分类与分布

杨亚科(Populoideae)植物自然分布于热带非洲和大约从北纬19°~70°度的北半球,由胡杨属(Balsamiflua)和杨属(Populus)2个属所组成。胡杨属间断分布于赤道非洲、古地中海地区和墨西哥,包含2个组(胡杨组、墨杨组)和约3个天然种。杨属分布于欧洲、亚洲、非洲(北缘)和北美洲的广大地区,包含大叶杨亚属(Subgen.Leucoides)(大叶杨组)、杨亚属(Subgen.Populus)(青杨组、黑杨组、杨组)2个亚属和约52个天然种。拟定了杨亚科属的检索表、胡杨属组和种的检索表、杨属亚属和组的检索表以及杨属中各组种的检索表。提供了一个杨树种类目录,包括它们的正名、异名、文献引注和地理分布等。     

Ecological prerequisites for spread of bloodsucking mosquitoes

The spread of mosquitoes beyond the initial ranges and the ecological prerequisites for colonization of new territories are considered for several mosquito species which are active bloodsuckers and vectors of many disease agents. The invasion of homodynamic Aedes aegypti from Africa into the tropical zone of several continents has probably occurred during the last 400 years by means of transportation of the eggs and larvae mainly by sea ships. In the new areas mosquitoes occupied breeding places similar to those in their native ranges. On the contrary, the urban mosquito Culex pipiens f. molestus, introduced from the subtropical areas of Africa into Europe and other continents in the XX century, found a new type of habitat: underground constructions with polluted water where the mosquito develops the year round. This was preconditioned by such specific biological features as autogeny, stenogamy, and homodynamy (seasonal development without diapause). Aedes albopictus originated from Southeast Asia and invaded four continents (Europe, North and South America, and Africa) in 1980–2000 owing to its high capacity of adaptation to various climatic conditions (high viability of eggs, variation in the ability for diapause and mechanisms of diapause control between the strains, etc.). The eggs and larvae of this mosquito were transported by sea in used car tires. The models predicting the distribution of invasive species and the ways of their spread (by sea, air, motor transport) are discussed.     

On the origin and distribution of the genus Salix in Qinghai-Xizang plateau

1. Uplifting of Qinghai-Xizang plateau has brought great influence on the origination and distribution of species inside the genus Salix. There are 91 sp. (incl. 2 cult. sp.), 16 var. and 3 f. belonging to 15 Sect. in this region, among these species the endemics attain to 58 sp., 14 var. and 3 f. So it has become one of the most important centres of distribution of Salix in the world. Species common with other regions attain only to 32. Thus it is also clear that correlation between salicaceous flora in this region and that of other regions is not so much developed, and that the salicaceous flora of Qinghai-Xizang plateau was mainly originated autochthonously during the upheaval of plateau. 2. Along a demarcation line delineated from Gyirong through Lhasa and Qamdo to Lanzhou, to the north-western region the total number of species of this genus is summed up to 7 sp. and 1 var. (incl. 2 cult. sp.), and they distribute only in the West Himalaya and Pamir-Kunlun regions. Besides 2 cult. sp., there is only 1 endemic, and others all should be migrants from Europe or West Asia. In the south-eastern part, because the climate is moister, the species of Salix may be summed up to 84 sp., 15 var. and 3 f., among them 73 sp., 20 var. and 3 f. are endemics, accounting for 68 percent of the total. 3. In East Himalaya and South Henduan Shan (southward of lat. 30°N.) there are 78 sp., 12 var. and 4 f., among them 50 sp., 10 var. and 2 f. are endemics. They represent the different stages of phylogenetic development of this genus. So here may be the centre of origination and distribution of Salix species in the all Sino-Himalaya flora. The common species between East Himalaya and South Henduan Shan regions attain to 41. Because the latter forms a part of Sichuan and Yunnan plateau and the former did not become a land until Quaternary Period, the plants of the former mainly are the migrants from the latter. 4. The most characteristic group of Salix in this region is Sect. Lindleyanae Schneid. with a total of 18 sp. and 1 var. This group adapting to the somewhat environment changes is quite different from Sect. Retusae A. Kern. in the Arctic and high mountains of higher latitudes in many characters, so it should be originated autochtonously, and it is certainly not a migrant from Arctic. This Sect. seems to be developed from Sect. Floccosae Hao and in turn from Sect. Sclerophyllae Schneid. and Sect. Denticulatae Schneid. This developmental direction has assumed an important branch in the phylogenetic development of the whole genus. 5. In addition, there are two interesting and important regions on the north-eastern and eastern to Qinghai-Xizang Plateau, i. e. on the north-east Anymaqen Shan (Amnemachin mountain) and on the east Qiong Lai Shan. There are many endemic species pertaining to these two parts, among these species some may be ancient relicts since Tertiary. It is to be expected that more additional scientific results will be obtainedafter some more extensive works done in these two regions.     

Critical assessment of the Lactarius gerardii species complex (Russulales)

This paper investigates species delimitation within the Lactarius gerardii species complex and explores its taxonomic and geographical extent. A combined molecular phylogeny based on ITS, LSU and rpb2 gene sequences is constructed and morphological characters are evaluated. While L. gerardii was originally described from North America, it has later been reported from all over Asia. Therefore a worldwide sampling range was aimed at, including species exhibiting morphological affinities with L. gerardii. The phylogenetic analyses indicate that intercontinental conspecificity in L. gerardii is absent. Thirty strongly supported clades are retrieved of which 18 are morphologically identifiable species. The group is elevated to Lactarius subg. Gerardii stat. nov. It includes, apart from L. gerardii s.l., L. atrovelutinus, L. bicolor, L. ochrogalactus, L. petersenii, L. reticulatovenosus, L. sepiaceus, L. subgerardii and L. wirrabara, as well as the pleurotoid L. uyedae. The paraphyletic nature of the genus Lactarius is confirmed. Lactarius subg. Gerardii appears not affiliated with L.?subg. Plinthogalus and this can be substantiated morphologically. No representatives are known from Europe, Africa or South America. The high frequency of intercontinental sister relationships observed between America, Asia and the Australian region, suggests multiple migration and speciation events have occurred across continents.     

Phylogeny, biogeography, and molecular dating of cornelian cherries (Cornus, Cornaceae): tracking Tertiary plant migration

Data from four DNA regions (rbcL, matK, 26S rDNA, and ITS) as well as extant and fossil morphology were used to reconstruct the phylogeny and biogeographic history of an intercontinentally disjunct plant group, the cornelian cherries of Cornus (dogwoods). The study tests previous hypotheses on the relative roles of two Tertiary land bridges, the North Atlantic land bridge (NALB) and the Bering land bridge (BLB), in plant migration across continents. Three approaches, the Bayesian, nonparametric rate smoothing (NPRS), and penalized likelihood (PL) methods, were employed to estimate the times of geographic isolations of species. Dispersal and vicariance analysis (DIVA) was performed to infer the sequence and directionality of biogeographic pathways. Results of phylogenetic analyses suggest that among the six living species, C. sessilis from western North America represents the oldest lineage, followed by C. volkensii from Africa. The four Eurasian species form a clade consisting of two sister pairs, C. mas-C. officinalis and C. chinensis-C. eydeana. Results of DIVA and data from fossils and molecular dating indicate that the cornelian cherry subgroup arose in Europe as early as the Paleocene. Fossils confirm that the group was present in North America by the late Paleocene, consistent with the DIVA predictions that, by the end of the Eocene, it had diversified into several species and expanded its distribution to North America via the NALB and to Africa via the last direct connection between Eurasia and Africa prior to the Miocene, or via long-distance dispersal. The cornelian cherries in eastern Asia appear to be derived from two independent dispersal events from Europe. These events are inferred to have occurred during the Oligocene and Miocene. This study supports the hypothesis that the NALB served as an important land bridge connecting the North American and European floras, as well as connecting American and African floras via Europe during the early Tertiary.     

Diversity and depletions in continental carnivore guilds: implications for prioritizing global carnivore conservation

Large carnivores are important ecosystem components but are extinction prone due to small populations, slow growth rates and large area requirements. Consequently, there has been a surge of carnivore conservation efforts. Such efforts typically target local populations, with limited attention to the effects on the ecosystem function of predator guilds. Also, there is no framework for prioritizing these efforts globally. We compared taxonomic and functional diversity of continental carnivore guilds, compared them with the corresponding guilds during the Late Pleistocene and synthesized our results into suggestions for global prioritizations for carnivore conservation. Recent extinctions have caused taxonomically and functionally depleted carnivore guilds in Europe and North and South America, contrasting with guilds in Africa and Asia, which have retained a larger proportion of their carnivores. However, Asia is at higher risk of suffering further extinctions than other continents. We suggest three priorities of contrasting urgency for global carnivore conservation: (i) to promote recovery of the threatened Asian species, (ii) to prevent species in the depleted guilds in Europe and North and South America from becoming threatened, and (iii) to reconstruct functionally intact sympatric guilds of large carnivores at ecologically effective population sizes.     

Niche shifts during the global invasion of the Asian tiger mosquito, Aedes albopictus Skuse (Culicidae), revealed by reciprocal distribution models

Aim Niche‐based distribution models are often used to predict the spread of invasive species. These models assume niche conservation during invasion, but invasive species can have different requirements from populations in their native range for many reasons, including niche evolution. I used distribution modelling to investigate niche conservatism for the Asian tiger mosquito (Aedes albopictus Skuse) during its invasion of three continents. I also used this approach to predict areas at risk of invasion from propagules originating from invasive populations. Location Models were created for Southeast Asia, North and South America, and Europe. Methods I used maximum entropy (Maxent ) to create distribution models using occurrence data and 18 environmental datasets. One native model was created for Southeast Asia; this model was projected onto North America, South America and Europe. Three models were created independently for the non‐native ranges and projected onto the native range. Niche overlap between native and non‐native predictions was evaluated by comparing probability surfaces between models using real data and random models generated using a permutation approach. Results The native model failed to predict an entire region of occurrences in South America, approximately 20% of occurrences in North America and nearly all Italian occurrences of A. albopictus. Non‐native models poorly predict the native range, but predict additional areas at risk for invasion globally. Niche overlap metrics indicate that non‐native distributions are more similar to the native niche than a random prediction, but they are not equivalent. Multivariate analyses support modelled differences in niche characteristics among continents, and reveal important variables explaining these differences. Main conclusions The niche of A. albopictus has shifted on invaded continents relative to its native range (Southeast Asia). Statistical comparisons reveal that the niche for introduced distributions is not equivalent to the native niche. Furthermore, reciprocal models highlight the importance of controlling bi‐directional dispersal between native and non‐native distributions.