The genus Sarcostemma R.Br. (Asclepiadaceae) in Madagascar

The Madagascar! representatives of the genus Sarcostemma are investigated. All Malagasy material studied can be assigned to four taxa. S. viminale ssp. viminale occurs in Madagascar as well as on other islands along the African coast and on the African mainland: the other three species are endemic to Madagascar. All four species occur in the southern, arid part of the island, to which S. decorsei is endemic. S. membranaceum and S. elachistemmoides are new. All species are described and illustrated and a key and distribution maps are presented.     

Systematics, speciation and biogeography of the dwarf chameleons (Brookesia; Reptilia, Squamata, Chamaeleontidae) of northern Madagascar

Brookesia dwarf chameleons, endemic to Madagascar, were surveyed at the following localities in northern Madagascar (north of 16°S): Montagne d'Ambre, Ankarana, Manongarivo, Tsaratanana, Marojejy and Masoala. A total of 15 species occur in this region. Six new species are described and five new synonyms are identified. The genus Brookesia , the most speciose chamaeleontid genus in Madagascar, contains 23 species.
Almost all the northern Brookesia species are restricted to rainforest and occupy a relatively narrow elevational range. Although the northern rainforests represent just one-third of the total rainforest and about 5% of the total island area, 65% of the Brookesia species occur in this region, and 52% are endemic to the northern rainforest. Five new biogeographic regions of the northern rainforest are identified based on centres of Brookesia endemicity: Montagne d'Ambre, Northwest, Tsaratanana, Northeast and East. Speciation is thought to have been facilitated in the north through geographic isolation, with the Tsaratanana mountain range and the dry forests south of Montagne d'Ambre forming barriers to dispersal, and the Tsaratanana mountains acting as a centre of isolation. The fragmented distribution of several Brookesia species of low altitude rainforest suggests a period in Madagascar's history when the climate was wetter and low altitude rainforest much more widespread.     

A partial systematic revision of the day geckos, Phelsuma Gray, of Madagascar (Reptilia: Squamata: Gekkonidae)

Recent survey work in Madagascar has led to significant changes in the systematics of Madagascan Phelsuma. A new species from the Masoala Peninsula in northeastern Madagascar is described, which has a nostril position typical of Phelsuma from Mauritius, Reunion and Rodriguez islands. Phelsuma breviceps was rediscovered in extreme southern Madagascar and is resurrected from the synonymy of P. mutabilis. Phelsuma breviceps has fragile skin, a probable predator escape mechanism, similar to the condition found in geckos of the genera Ailuronyx and Geckokpis. Three new synonyms are recognized. Phelsuma befotahensis and P. checki are junior synonyms of P. abbotti , and P. minuthi is a junior synonym of P. lineata. Twenty species of Phelsuma occur in Madagascar, of which 16 are endemic. A checklist and identification key are provided. Conservation problems of Phelsuma in the coastal regions of Madagascar are briefly discussed.     

Systematic revision of the genus Aglyptodactylus Boulenger, 1919 (Amphibia: Ranidae), and analysis of its phylogenetic relationships to other Madagascan ranid genera (Tomopterna, Boophis, Mantidactylus, and Mantella)

Recent field studies revealed two new species of the genus Aglyptodactylus (Amphibia: Anura: Ranidae), which was hitherto considered as monotypic and confined to humid eastern Madagascar. Both new species, Aglyptodactylus laticeps sp. n. and Aglyptodactylus securifer sp. n. , occur syntopically in the deciduous dry forest of Kirindy in western Madagascar. In comparison to Aglyptodactylus madagascariensis from eastern rainforests, the new species A. laticeps shows a remarkable morphological divergence, which may be partly due to adaptations to burrowing habits in dry environments. Despite of the morphological differentiation, advertisement calls and osteology indicate that all three species of Aglyptodactylus are closely related. A phylogenetic analysis of the Madagascan ranid genera Aglyptodactylus, Mantella, Mantidactylus, Boophis , and Tomopterna (the latter including species from Madagascar, Africa, and Asia) strongly supports a sister group relationship of Aglyptodactylus with the ranine genus Tomopterna . We therefore transfer Aglyptodactylus from the Rhacophorinae to the Raninae and discuss implications of this rearrangement for ranoid systematics. The existence of the endemic genus Aglyptodactylus in Madagascar as well as its close phylogenetic relationships to Tomopterna confirm that the Raninae were already present on the Madagascan plate before its separation from Africa. The Madagascan Tomopterna labrosa shows several important differences both to Asian and to African species of the genus, and is therefore transferred from the subgenus Sphaerotheca (now restricted to Asia) to a new subgenus Laliostoma subgen. n .     

Independent gene phylogenies and morphology demonstrate a malagasy origin for a wide-ranging group of swallowtail butterflies

Madagascar is home to numerous endemic species and lineages, but the processes that have contributed to its endangered diversity are still poorly understood. Evidence is accumulating to demonstrate the importance of Tertiary dispersal across varying distances of oceanic barriers, supplementing vicariance relationships dating back to the Cretaceous, but these hypotheses remain tentative in the absence of well-supported phylogenies. In the Papilio demoleus group of swallowtail butterflies, three of the five recognized species are restricted to Madagascar, whereas the remaining two species range across the Afrotropical zone and southern Asia plus Australia. We reconstructed phylogenetic relationships for all species in the P. demoleus group, as well as 11 outgroup Papilio species, using 60 morphological characters and about 4 kb of nucleotide sequences from two mitochondrial (cytochrome oxidase I and II) and two nuclear (wg and EF-1alpha) genes. Of the three endemic Malagasy species, the two that are formally listed as endangered or at risk represented the most basal divergences in the group, while the more common third endemic was clearly related to African P. demodocus. The fifth species, P. demoleus, showed little differentiation across southern Asia, but showed divergence from its subspecies sthenelus in Australia. Dispersal-vicariance analysis using cladograms derived from morphology and three independent genes indicated a Malagasy diversification of lime swallowtails in the middle Miocene. Thus, diversification processes on the island of Madagascar may have contributed to the origin of common butterflies that now occur throughout much of the Old World tropical and subtemperate regions. An alternative hypothesis, that Madagascar is a refuge for ancient lineages resulting from successive colonizations from Africa, is less parsimonious and does not explain the relatively low continental diversity of the group.     

An endemic radiation of Malagasy songbirds is revealed by mitochondrial DNA sequence data

The bird fauna of Madagascar includes a high proportion of endemic species, particularly among passerine birds (Aves: Passeriformes). The endemic genera of Malagasy songbirds are not allied obviously with any African or Asiatic taxa, and their affinities have been debated since the birds first were described. We used mitochondrial sequence data to estimate the relationships of 13 species of endemic Malagasy songbirds, 17 additional songbird species, and one species of suboscine passerine. In our optimal trees, nine of the 13 Malagasy species form a clade. although these birds currently are classified in three different families. In all optimal trees, the sister to this endemic clade is a group of Old World warblers including both African and Malagasy birds. The endemic Malagasy songbird clade rivals other island radiations, including the vangas of Madagascar and the finches of the Galapagos, in ecological diversity.     

The antiquity of Madagascar’s grasslands and the rise of C4 grassy biomes

Aim Grasslands and savannas, which make up > 75% of Madagascar’s land area, have long been viewed as anthropogenically derived after people settled on the island c. 2 ka. We investigated this hypothesis and an alternative – that the grasslands are an insular example of the post‐Miocene spread of C₄ grassy biomes world‐wide. Location Madagascar, southern Africa, East Africa. Methods We compared the number of C₄ grass genera in Madagascar with that in southern and south‐central African floras. If the grasslands are recent we would expect to find fewer species and genera in Madagascar relative to Africa and for these species and genera to have very wide distribution ranges in Madagascar. Secondly, we searched Madagascan floras for the presence of endemic plant species or genera restricted to grasslands. We also searched for evidence of a grassland specialist fauna with species endemic to Madagascar. Plant and animal species endemic to C₄ grassy biomes would not be expected if these are of recent origin. Results Madagascar has c. 88 C₄ grass genera, including six endemic genera. Excluding African genera with only one or two species, Madagascar has 86.6% of southern Africa’s and 89.4% of south‐central Africa’s grass genera. C₄ grass species make up c. 4% of the flora of both Madagascar and southern Africa and species : genus ratios are similar (4.3 and 5.1, respectively). Turnover of grasses along geographical gradients follows similar patterns to those in South Africa, with Andropogoneae dominating in mesic biomes and Chlorideae in semi‐arid grassy biomes. At least 16 monocot genera have grassland members, many of which are endemic to Madagascar. Woody species in frequently burnt savannas include both Madagascan endemics and African species. A different woody flora, mostly endemic, occurs in less frequently burnt grasslands in the central highlands, filling a similar successional niche to montane C₄ grasslands in Africa. Diverse vertebrate and invertebrate lineages have grassland specialists, including many endemic to Madagascar (e.g. termites, ants, lizards, snakes, birds and mammals). Grassland use of the extinct fauna is poorly known but carbon isotope analysis indicates that a hippo, two giant tortoises and one extinct lemur ate C₄ or CAM (crassulacean acid metabolism) plants. Main conclusions The diversity of C₄ grass lineages in Madagascar relative to that in Africa, and the presence of plant and animal species endemic to Madagascan grassy biomes, does not fit the view that these grasslands are anthropogenically derived. We suggest that grasslands invaded Madagascar after the late Miocene, part of the world‐wide expansion of C₄ grassy biomes. Madagascar provides an interesting test case for biogeographical analysis of how these novel biomes assembled, and the sources of the flora and fauna that now occupy them. A necessary part of such an analysis would be to establish the pre‐settlement extent of the C₄ grassy biomes. Carbon isotope analysis of soil organic matter would be a feasible method for doing this.     

Taxonomic study of Astragalus sect Erioceras (Fabaceae) in Iran Additional notes and key to the species

A key to and new findings on the Astragalus sect. Erioceras, are given for the 10 species of this section, which occur within the area covered by the flora of Iran. One species, Astragalus neo-sytinii , is described as a new species. A. sympileicarpus is reported as a new record for the flora of Iran. A. viridis is transferred from A. sect. Erioceras to sect. Xiphidium Sect. Acantherioceras is reduced to the level of subsection. The differences between that section and closely related sections are discussed.     

The Leguminosae of Madagascar

A revision of the Leguminosae of Madagascar is soon to be completed, covering some 670 species (c. 565 native to Madagascar of which 449 endemic) including 6 new genera and 121 new species. It has provided the basis for a pilot project applying computer mapping (GIS) to the investigation of ecological parameters which determine the extent of species distributions. Vegetation maps, based on these parameters, are being used for planning and managing the conservation of biodiversity in Madagascar.     

Multiple overseas dispersal in amphibians

Amphibians are thought to be unable to disperse over ocean barriers because they do not tolerate the osmotic stress of salt water. Their distribution patterns have therefore generally been explained by vicariance biogeography. Here, we present compelling evidence for overseas dispersal of frogs in the Indian Ocean region based on the discovery of two endemic species on Mayotte. This island belongs to the Comoro archipelago, which is entirely volcanic and surrounded by sea depths of more than 3500 m. This constitutes the first observation of endemic amphibians on oceanic islands that did not have any past physical contact to other land masses. The two species of frogs had previously been thought to be nonendemic and introduced from Madagascar, but clearly represent new species based on their morphological and genetic differentiation. They belong to the genera Mantidactylus and Boophis in the family Mantellidae that is otherwise restricted to Madagascar, and are distinguished by morphology and mitochondrial and nuclear DNA sequences from mantellid species occurring in Madagascar. This discovery permits us to update and test molecular clocks for frogs distributed in this region. The new calibrations are in agreement with previous rate estimates and indicate two further Cenozoic transmarine dispersal events that had previously been interpreted as vicariance: hyperoliid frogs from Africa to Madagascar (Heterixalus) and from Madagascar to the Seychelles islands (Tachycnemis). Our results provide the strongest evidence so far that overseas dispersal of amphibians exists and is no rare exception, although vicariance certainly retains much of its importance in explaining amphibian biogeography.     

Resource shifts in Malagasy dung beetles: contrasting processes revealed by dissimilar spatial genetic patterns

The endemic dung beetle subtribe Helictopleurina has 65 species mostly in wet forests in eastern Madagascar. There are no extant native ungulates in Madagascar, but three Helictopleurus species have shifted to the introduced cattle dung in open habitats in the past 1500 years. Helictopleurus neoamplicollis and Helictopleurus marsyas exhibit very limited cytochrome oxidase subunit 1 haplotype diversity and a single haplotype is present across Madagascar, suggesting that these species shifted to cattle dung in a small region followed by rapid range expansion. In contrast, patterns of molecular diversity in Helictopleurus quadripunctatus indicate a gradual diet shift across most of southern Madagascar, consistent with somewhat broader diet in this species. The three cattle dung-using Helictopleurus species have significantly greater geographical ranges than the forest-dwelling species, apparently because the shift to the currently very abundant new resource relaxed interspecific competition that hinders range expansion in the forest species.     

Integrative taxonomy and phylogeny of leafless Vanilla orchids from the South-West Indian Ocean region reveal two new Malagasy species

The leafless Vanilla species complex from the South-West Indian Ocean (SWIO) region has long been a taxonomic challenge, due to limited patterns of morphological differentiation and an absence of variation within chloroplast sequences. This complex includes seven known morphospecies: V. madagascariensis, V. bosseri, V. decaryana, and V. perrieri endemic to Madagascar, V. humblotii presumed as endemic to the Comoros Archipelago, but also present in Madagascar, V. roscheri from the East African coast, and V. phalaenopsis endemic to Seychelles. A previous population genetic study using microsatellite markers allowed us to distinguish, in addition to the five recognized Malagasy taxa, two other genetic clusters present in the East of the island. An integrative taxonomy approach was therefore conducted by combining microsatellite and morphological data used in the previous study with new data sets, and by adding ITS sequencing data, to validate the taxonomic level of these Malagasy genetic clusters and unravel phylogenetic relationships between SWIO species. As a result, based on phylogenetic, genotypic and morphological evidence, nine species were discriminated in the SWIO region, including seven in Madagascar, with two new eastern species. The leafless Vanilla group originated and diversified in Madagascar, from an ancestor of African descent, with three subsequent independent colonization events from Madagascar to the other territories of SWIO within the two main lineages (white versus yellow flower species). The new Malagasy species, V. allorgeae Andriamihaja & Pailler sp. nov., and V. atsinananensis Andriamihaja & Pailler sp. nov., are described and a new identification key is proposed.     

Molecular and cytogenetic evidence for cryptic speciation within a rare endemic Malagasy lemur, the Northern Sportive Lemur (Lepilemur septentrionalis)

Evolutionary relationships of different populations of the threatened malagasy lemur Lepilemur septentrionalis were assessed by sequence analysis of mitochondrial DNA (D-loop region and partial Cyt b gene). One hundred and fifty nine samples were collected from five main different localities in the northern part of Madagascar. We applied the phylogenetic species concept based on fixed diagnostic differences to determine the status of different geographical populations. No nucleotide site diagnoses Ankarana from Andrafiamena or Analamera. However, numerous fixed differences separate Sahafary from all other populations. These results were corroborated by phylogenetic trees. As previous cytogenetic studies, our molecular data suggest that two cryptic species of Lepilemur occur in the extreme north of Madagascar. This speciation is probably caused by chromosomal rearrangements in at least one of the evolutionary lineages. Our study comprises another striking example of how molecular genetic assay can detect phylogenetic discontinuities that are not reflected in traditional morphologically based taxonomies. Our study indicates that the Sahafary population is a hitherto undescribed endangered endemic species which urgently needs conservation efforts.     

Extinction Risks and the Conservation of Madagascar's Reptiles

Background

An understanding of the conservation status of Madagascar''s endemic reptile species is needed to underpin conservation planning and priority setting in this global biodiversity hotspot, and to complement existing information on the island''s mammals, birds and amphibians. We report here on the first systematic assessment of the extinction risk of endemic and native non-marine Malagasy snakes, lizards, turtles and tortoises.

Methodology/Principal Findings

Species range maps from The IUCN Red List of Threatened Species were analysed to determine patterns in the distribution of threatened reptile species. These data, in addition to information on threats, were used to identify priority areas and actions for conservation. Thirty-nine percent of the data-sufficient Malagasy reptiles in our analyses are threatened with extinction. Areas in the north, west and south-east were identified as having more threatened species than expected and are therefore conservation priorities. Habitat degradation caused by wood harvesting and non-timber crops was the most pervasive threat. The direct removal of reptiles for international trade and human consumption threatened relatively few species, but were the primary threats for tortoises. Nine threatened reptile species are endemic to recently created protected areas.

Conclusions/Significance

With a few alarming exceptions, the threatened endemic reptiles of Madagascar occur within the national network of protected areas, including some taxa that are only found in new protected areas. Threats to these species, however, operate inside and outside protected area boundaries. This analysis has identified priority sites for reptile conservation and completes the conservation assessment of terrestrial vertebrates in Madagascar which will facilitate conservation planning, monitoring and wise-decision making. In sharp contrast with the amphibians, there is significant reptile diversity and regional endemism in the southern and western regions of Madagascar and this study highlights the importance of these arid regions to conserving the island''s biodiversity.     

金盏苣苔属(苦苣苔科)的第二次校订

金盏苣苔属(Isometrum Craib)属于苦苣苔亚科(Cyrtandroideae)长蒴苣苔族(Didymocarpcae),是由W.G.Craib 1919根据I.farreri Craib建立的,同年他又把Didissandra glandulosa Batalin置于该属,1960年B.L.Burtt又把Didi-sandra Clarke中的4个种(即:D.prumuliflora Batalim,D.giraldii Diels,D.fargesii Franch.和D.leucantha Diels)移入该属。作者在编写中国植物志苦苣苔     

嵩草属地理分布的研究

嵩草属Kobresia Willd.隶属于莎草科,全世界有64种5变种,中国有49种4变种,属下分为4个组。该属主要分布于北半球温带至寒带,亚洲种类最多,主要集中分布于喜马拉雅山地区和横断山地区。上述两地共有总数的90％以上的种类。因此,喜马拉雅-横断山地区为嵩草属的分布中心。与嵩草属最近缘的属Schoenoxiphium只分布在马达加斯加和非洲东南部山地。两个属可能有共同的祖先,发生于冈瓦纳古陆。随着印度板块与非洲大陆分离并向北方漂移,嵩草属的祖先被带到欧亚大陆,在两个板块相遇处——喜马拉雅-横断山地区产生了现在的嵩草属。其后,喜马拉雅山脉进一步抬升,气候与环境发生巨变,嵩草属也进一步分化形成现在的规模。印度板块在早第三纪与欧亚大陆相连接,嵩草属可能就是此时起源于喜马拉雅山地区,并开始分化,且沿北半球的山系向北扩散到欧洲和西伯利亚,又从欧洲到格陵兰再到加拿大东部,从西伯利亚通过白令海峡到阿拉斯加并沿落基山脉南下达到美国的科罗拉多,形成了嵩草属现今的分布格局。     

Comprehensive Red List Assessment Reveals Exceptionally High Extinction Risk to Madagascar Palms

The establishment of baseline IUCN Red List assessments for plants is a crucial step in conservation planning. Nowhere is this more important than in biodiversity hotspots that are subject to significant anthropogenic pressures, such as Madagascar. Here, all Madagascar palm species are assessed using the IUCN Red List categories and criteria, version 3.1. Our results indicate that 83% of the 192 endemic species are threatened, nearly four times the proportion estimated for plants globally and exceeding estimates for all other comprehensively evaluated plant groups in Madagascar. Compared with a previous assessment in 1995, the number of Endangered and Critically Endangered species has substantially increased, due to the discovery of 28 new species since 1995, most of which are highly threatened. The conservation status of most species included in both the 1995 and the current assessments has not changed. Where change occurred, more species have moved to lower threat categories than to higher categories, because of improved knowledge of species and their distributions, rather than a decrease in extinction risk. However, some cases of genuine deterioration in conservation status were also identified. Palms in Madagascar are primarily threatened by habitat loss due to agriculture and biological resource use through direct exploitation or collateral damage. The recent extension of Madagascar’s protected area network is highly beneficial for palms, substantially increasing the number of threatened species populations included within reserves. Notably, three of the eight most important protected areas for palms are newly designated. However, 28 threatened and data deficient species are not protected by the expanded network, including some Critically Endangered species. Moreover, many species occurring in protected areas are still threatened, indicating that threatening processes persist even in reserves. Definitive implementation of the new protected areas combined with local community engagement are essential for the survival of Madagascar’s palms.