East Africa is a biodiversity hotspot. Haplocarpha rueppelii （Sch.Bip.） Beauverd is mainly distributed in the alpine grassland of East Africa. Here we sampled 65 individuals of eight populations/locations of H. ruep...East Africa is a biodiversity hotspot. Haplocarpha rueppelii （Sch.Bip.） Beauverd is mainly distributed in the alpine grassland of East Africa. Here we sampled 65 individuals of eight populations/locations of H. rueppelii including hairy and glabrous forms from Mts. Elgon, Aberdare, Kenya, Kilimanjaro and Bale Mountains. We then sequenced one nuclear and three chloroplast DNA fragments and conducted phylogeographic analyses to test the taxonomic rank of the two forms and causes for the differentiation （intrinsic reproductive isolation and geographic barrier）. The results demonstrate that the species consists of two major groups, one includes the populations from Mts. Elgon, Aberdare and Bale, while the other includes Mts. Kenya and Kilimanjaro. The species has established in Mts. Kenya and Aberdare during the Pleistocene. However, migration rate for individuals between the two mountains was low as showed by gene flow analysis. A barrier for plant dispersal and gene flow would have existed between Mts. Aberdare and Kenya since at least Pleistocene. No change of the taxonomic concept of this species is needed. This study reveals a potential geographic barrier in East Africa. We hope it will arouse more scientists＇ interests in phylogeography and biodiversity of East Africa.展开更多
The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of ...The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of uncertain relationships. In commonly accepted global regionalization schemata, Madagascar is treated together with Africa for animals, and with Africa, tropical Asia and the Pacific islands in the case of plants. Here we examine the similarities between the biotic assemblages of （i） tropical Africa, （ii） Madagascar, and （iii） the rest of the world, on a basic taxonomic level, considering the families of vascular plants and vertebrates as analysis units. The percentages of endemic families, families shared pair-wise between regions, or pre- sent in all three, are roughly similar between the two broad groups, though plant families with ranges limited to one region are proportionally fewer. In dendrograms and multidimensional scaling plots for different groups, Madagascar clusters together with Africa, Asia or both, and sometimes with smaller Indian Ocean Islands, but quite often （though not in plants） as a convincingly separate cluster. Our results for vertebrates justify the status of full zoogeographic region for Madagascar, though an equally high rank in geobotanical regionalization would mean also treating Africa and Tropical Asia as separate units, which would be debata- ble given the overall greater uniformity of plant assemblages. Beyond the Madagascan focus of this paper, the differences be- tween plant and vertebrate clusters shown here suggest different levels of ecological plasticity at the same taxonomic level, with plant families being much more environmentally-bound, and thus clustering along biome lines rather than regional lines [Current Zoology 58 （3）： 363-374, 2012].展开更多
基金supported by Sino-Africa Joint Research Center(Y323771W07,SAJC201322)the National Natural Science Foundation of China(31300182)
文摘East Africa is a biodiversity hotspot. Haplocarpha rueppelii （Sch.Bip.） Beauverd is mainly distributed in the alpine grassland of East Africa. Here we sampled 65 individuals of eight populations/locations of H. rueppelii including hairy and glabrous forms from Mts. Elgon, Aberdare, Kenya, Kilimanjaro and Bale Mountains. We then sequenced one nuclear and three chloroplast DNA fragments and conducted phylogeographic analyses to test the taxonomic rank of the two forms and causes for the differentiation （intrinsic reproductive isolation and geographic barrier）. The results demonstrate that the species consists of two major groups, one includes the populations from Mts. Elgon, Aberdare and Bale, while the other includes Mts. Kenya and Kilimanjaro. The species has established in Mts. Kenya and Aberdare during the Pleistocene. However, migration rate for individuals between the two mountains was low as showed by gene flow analysis. A barrier for plant dispersal and gene flow would have existed between Mts. Aberdare and Kenya since at least Pleistocene. No change of the taxonomic concept of this species is needed. This study reveals a potential geographic barrier in East Africa. We hope it will arouse more scientists＇ interests in phylogeography and biodiversity of East Africa.
文摘The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of uncertain relationships. In commonly accepted global regionalization schemata, Madagascar is treated together with Africa for animals, and with Africa, tropical Asia and the Pacific islands in the case of plants. Here we examine the similarities between the biotic assemblages of （i） tropical Africa, （ii） Madagascar, and （iii） the rest of the world, on a basic taxonomic level, considering the families of vascular plants and vertebrates as analysis units. The percentages of endemic families, families shared pair-wise between regions, or pre- sent in all three, are roughly similar between the two broad groups, though plant families with ranges limited to one region are proportionally fewer. In dendrograms and multidimensional scaling plots for different groups, Madagascar clusters together with Africa, Asia or both, and sometimes with smaller Indian Ocean Islands, but quite often （though not in plants） as a convincingly separate cluster. Our results for vertebrates justify the status of full zoogeographic region for Madagascar, though an equally high rank in geobotanical regionalization would mean also treating Africa and Tropical Asia as separate units, which would be debata- ble given the overall greater uniformity of plant assemblages. Beyond the Madagascan focus of this paper, the differences be- tween plant and vertebrate clusters shown here suggest different levels of ecological plasticity at the same taxonomic level, with plant families being much more environmentally-bound, and thus clustering along biome lines rather than regional lines [Current Zoology 58 （3）： 363-374, 2012].
