Multi-scale determinants of dung beetle assemblage structure across abiotic gradients of the Kalahari–Nama Karoo ecotone, South Africa

Aim Changing conditions across spatial gradients are primary determinants of biotic regions, local habitats, and distributional edges. We investigate how a climatic gradient and edaphic mosaic interact as multi‐scale drivers of spatial patterns in scarabaeine dung beetles. The patterns are tested for congruency with ecoregion and floral boundaries over the same gradient, as responses to physical factors often differ among higher taxa. Location Southern Africa and the Nama Karoo–Kalahari ecotone, Northern Cape, South Africa. Methods Data consisted of the climatic distributions of 104 species and their abundances at 223 sites in two ecoregions/floral biomes, four bioregions, and 13 vegetation units. Factor analyses determined the biogeographical composition of the species, and regional‐ to local‐scale patterns in species abundance structure. Hierarchical analysis of oblique factors determined the proportional contribution of spatial variance to patterns. One‐way anova was used to test for significant separation of patterns along factor axes. Stepwise multiple regression was used to determine correlations of five physical attributes with species richness, Shannon‐Wiener diversity, and factor loadings for the study sites. Results Four biogeographical influences overlap in the study region, although rank contribution declines from south‐west arid through north‐east savanna to widespread and south‐east highland taxa. Species abundance structure comprises five subregional patterns, two centred to the north‐east (Kalahari, Isolated Kalahari Dune) dominated by Kalahari influence, and three to the south‐west (Nama Karoo subdivisions: Bushmanland, ‘Upper’, ‘Stony Prieska’) dominated by south‐west arid influence. Kalahari deep sands are characterized especially by a warmer, moister climate, whereas the Nama Karoo mosaic of deep or stony soils is characterized especially by north‐west aridity (Bushmanland), south‐east cooler temperatures (‘Upper’), or excessively stony soils (‘Stony Prieska’). Four of the subregional patterns each comprised three localized patterns related primarily to relative stoniness, edge effects from geographical position, or incidence of rainfall. Species richness and diversity declined with decreasing rainfall and increasing stoniness. Main conclusions Climatic and edaphic factors are important multi‐scale determinants of spatial patterns in dung beetle assemblage structure, with edaphic factors becoming more important at local spatial scales. The patterns are roughly congruent with the Kalahari Savanna–Nama Karoo ecotone at the floral biome or ecoregion scale, but show limited coincidence with finer‐scale floral classification.     

Climate and the evolution of annual/perennial life-histories in Nemesia (Scrophulariaceae)

The Cape Floristic Region and the Succulent Karoo in southwestern Africa are both noted for their plant species richness and high levels of endemism. The southwestern tip of Africa is one of the world's five Mediterranean-type climate regions. The biodiversity in the Cape Floristic Region and Succulent Karoo is thought to be at least partly due to changes to the climate of these regions that have occurred since the middle Miocene. Annual species are usually a significant proportion of local flora in Mediterranean-type climate regions. Previous studies of species radiations in the Cape Floristic Region have concentrated on genera that predominantly contain perennial species. Nemesia (Scrophulariaceae) comprises c. 65 species of annual and perennial herbs and sub-shrubs that are native to southern and tropical Africa. Annuals make up a significant proportion (~75%) of Nemesia species. We have reconstructed a phylogeny of 23 Nemesia species using nucleotide sequences of the ITS, ETS and trnL-spacer regions. Species were grouped into five clades, two composed of annual species, one that contained two annual and one perennial species, one that contained one annual and two perennial species, and one that was predominantly composed of perennial species. Phylogenetic dating of the ITS + ETS based phylogenetic tree using penalised likelihood suggested the genus evolved during the Miocene, and that the majority of extant Nemesia species studied radiated during the Pliocene. Ancestral state reconstruction supports at least three separate origins of the annual habit from plants with a perennial life history. One origin can be traced to the late Miocene while the other two transitions occurred more recently during the Pliocene. The transition from perennial to annual life-histories in Nemesia may have been a response to climate change.     

Small mammal (rodents and lagomorphs) European biogeography from the Late Oligocene to the mid Pliocene

Aim To analyse the fossil species assemblages of rodents and lagomorphs from the European Neogene in order to assess what factors control small mammal biogeography at a deep‐time evolutionary time‐scale. Location Western Europe: 626 fossil‐bearing localities located within 31 regions and distributed among 18 successive biochronological units ranging from c. 27 Ma (million years ago; Late Oligocene) to c. 3 Ma (mid Pliocene). Methods Taxonomically homogenized pooled regional assemblages are compared using the Raup and Crick index of faunal similarity; then, the inferred similarity matrices are visualized as neighbour‐joining trees and by projecting the statistically significant interregional similarities and dissimilarities onto palaeogeographical maps. The inferred biogeographical patterns are analysed and discussed in the light of known palaeogeographical and palaeoclimatic events. Results Successive time intervals with distinct biogeographical contexts are identified. Prior to c. 18 Ma (Late Oligocene and Early Miocene), a relative faunal homogeneity (high interregional connectivity) is observed all over Europe, a time when major geographical barriers and a weak climatic gradient are known. Then, from the beginning of the Middle Miocene onwards, the biogeography is marked by a significant decrease in interregional faunal affinities which matches a drastic global climatic degradation and leads, in the Late Miocene (c. 11 Ma), to a marked latitudinal pattern of small mammal distribution. In spite of a short rehomogenization around the Miocene/Pliocene boundary (6–4 Ma), the biogeography of small mammals in the mid Pliocene (c. 3 Ma) finally closely reflects the extant situation. Main conclusions The resulting biogeographical evolutionary scheme indicates that the extant endemic situation has deep historical roots corresponding to global tectonic and climatic events acting as primary drivers of long‐term changes. The correlation of biogeographical events with climatic changes emphasizes the prevalent role of the climate over geography in generating heterogeneous biogeographical patterns at the continental scale.     

Climatic and biogeographical associations of southern African dung beetles (Coleoptera: Scarabaeidae s. str.)

Climatic and biogeographical associations of southern African dung beetles (Scarabaeinae, Coprinae) were analysed from a collection amassed between 1971 and 1986. Endemism to Africa south of 15°S was much greater in southwesterly climates (winter rainfall, bimodal spring/autumn rainfall, arid late summer rainfall) than to the north‐east in the moist, mid‐summer rainfall region. Major biogeographical groups centred to the south‐west comprised predominantly southern African endemics, Western/Eastern Cape coast, Karoo, Karoo/Namib, northern Namibia and the south‐western Kalahari. Biogeographical groups centred on the south‐eastern highlands and the subtropical east coast (mid‐summer rainfall) also comprised predominantly southern African endemics. All other major groups centred to the north‐east in the mid‐summer rainfall region comprised predominantly species with widespread tropical biogeographical affiliations, pan‐southern Africa but centred in the east, pan‐mid‐summer rainfall region, eastern mid‐summer rainfall region, tropical east Zimbabwe/central Moçambique, subtropical/tropical game reserves (non‐ruminant dung specialists). There were cross‐climatic differences in taxonomic composition of the fauna. Within the winter rainfall region, percentage species composition of Scarabaeinae was greater whereas that of the coprine tribe, Onthophagini, was lower than within the other three climatic regions. Percentage species richness of most other tribes of Coprinae differed little between most climates but that of Scarabaeinae declined from west to east (Canthonini, Scarabaeini), east to west (Sisyphini) or to either side of the late summer rainfall region (Gymnopleurini).     

Alien plant assemblages near roads in arid and semi-arid South Africa

Herbaceous and woody alien plants visible from a moving vehicle were recorded along 1 km roadside transects at 5 km intervals over a distance of 5869 km in the semi-arid and arid Fynbos, Succulent Karoo, Nama Karoo and Arid Savanna (Kalahari) biomes in South Africa. Each 1 km transect was classified by biome and vegetation type, mean annual rainfall, rainfall seasonality, soil surface type and landuse adjoining the roadside. Although travelling speed affected the range and frequency of plant species observed, the method was repeatable at a speed of 100 km h^?1. Alien plants occurred in 98% of 119 Fynbos, 81% of 204 Succulent Karoo, 72% of 661 Nama Karoo, 47% of 171 Arid Savanna and 100% of seventeen Grassland transects. Alien species richness per site was correlated with mean annual rainfall, but in all regions, sites adjacent to cultivation had significantly more alien species than sites adjoining rangeland. The alien plant assemblage of the arid winter-rainfall Succulent Karoo included species from mesic winter-rainfall lowland Fynbos and the arid Nama Karoo receives unseasonal rainfall. The frequencies of Prosopis spp., Atriplex spp. and Opuntia ficus-indica were not significantly greater near cultivation, and these perennial plants, all of which are dispersed by indigenous and domestic animals, can invade natural rangeland in arid and semi-arid southern Africa.     

Hierarchical processes define spatial pattern of avian assemblages restricted and endemic to the arid Karoo, South Africa

Abstract Aim To identify and quantify biotic and abiotic factors associated with the regional gradients in the distribution and abundance of bird communities restricted and endemic to the Succulent and Nama Karoo biomes of South Africa. Location The arid Nama and Succulent Karoo biomes in South Africa. Methods The quarter degree grid cell (QDGC) was used to extract environmental data, while the bird data previously atlased, was linked to the same geo‐referenced system, using a geographical information system (GIS). Bird species were grouped into different life‐history assemblages. A quantitative, systematic analysis of the different bird communities spanning the Karoo was undertaken to examine contributions of broad‐ and local‐scale physical environmental and biotic factors to regional variations in the species composition, using multivariate statistical and spatial analytical tools. These included two indirect gradient methods; principal components analysis (PCA) and detrended correspondence analysis (DCA), and two direct gradient methods; canonical correspondence analysis (CCA) and redundancy analysis (RDA). Results Principal components analysis results showed that the selected environmental variables accounted for about 85% of the variation in the region. The first two principal gradients defined regional temperature seasonality and variability especially in winter and summer. The third principal gradient mainly defined summer rainfall areas in association with the coefficient of variation of rain and regional primary production, while the fourth gradient defined winter rainfall areas, growth days and elements of landscape structure. CCA/RDA analysis produced shortened hierarchically ranked explanatory variables for each bird assemblage. Stepwise gradient analysis results showed summer rain, rainfall concentration, topographic heterogeneity and annual evapotranspiration, as the most important climate variables explaining species occurrence. Landscape, in terms of percentage transformation, morphology, coefficient of variation of primary productivity and distance between suitable habitat patches, were also important, but to a lesser degree. Total variation explained (TVE) by the supplied variables was between 23 and 37% of variation. Less than 20% of TVE was the intrinsic spatial component of environmental influence, indicating that any unmeasured factors were independent of spatial structuring. For all the eight bird assemblages, climate contributed most to TVE (24–57%). Landscape characteristics (human‐induced transformation, vegetation in terms of size if grassy clumps and the average distances between them) contributed theleast to TVE for all the different assemblages (0–6%), especially the granivorous assemblage where it was not significant at all (0%). Seasonal extremes and variability were more important in explaining species gradients than were annual climatic conditions, with the exception of annual potential evapotranspiration. Main conclusions This study was able to synthesize species environment relations at the broad scale and demonstrated the association of arid zone endemic species occurrence with climate extremes and seasonality. Given the predicted climate change scenarios for South Africa, this regional gradient study provides a quantitative ecological basis for finer scale modelling and analysis, developing regional strategies for conserving biodiversity as well as predicting and planning for the effects of global climate change. However, most importantly, it clearly showed that bird species restricted and endemic to the arid Karoo biome may be more sensitive to climate rather than vegetation structure as previously thought.     

The partitioning of Africa: statistically defined biogeographical regions in sub‐Saharan Africa

Aim To test whether it is possible to establish a common biogeographical regionalization for plants and vertebrates in sub‐Saharan Africa (the Afrotropical Region), using objective multivariate methods. Location Sub‐Saharan Africa (Afrotropical Region). Methods We used 1° grid cell resolution databases for birds, mammals, amphibians and snakes (4142 vertebrate species) and c. 13% of the plants (5881 species) from the Afrotropical Region. These databases were analysed using cluster analysis techniques to define biogeographical regions. A β(sim) dissimilarity matrix was subjected to a hierarchical classification using the unweighted pair‐group method with arithmetic averages (UPGMA). The five group‐specific biogeographical regionalizations were compared against a regionalization developed from a combined database, and a regionalization that is maximally congruent with the five group‐specific datasets was determined using a consensus classification. The regionalizations were interpreted against measures of spatial turnover in richness and composition for the five datasets as well as the combined dataset. Results We demonstrate the existence of seven well‐defined and consistent biogeographical regions in sub‐Saharan Africa. These regionalizations are statistically defined and robust between groups, with minor taxon‐specific biogeographical variation. The proposed biogeographical regions are: Congolian, Zambezian, Southern African, Sudanian, Somalian, Ethiopian and Saharan. East Africa, the West African coast, and the transitions between the Congolian, Sudanian and Zambezian regions are unassigned. The Cape area in South Africa, Afromontane areas and the coastal region of East Africa do not emerge as distinct regions but are characterized by high neighbourhood heterogeneity, rapid turnover of species and high levels of narrow endemism. Main conclusions Species distribution data and modern cluster analysis techniques can be used to define biogeographical regions in Africa that reflect the patterns found in both vertebrates and plants. The consensus of the regionalizations between different taxonomic groups is high. These regions are broadly similar to those proposed using expert opinion approaches. Some previously proposed transitional zones are not recognized in this classification.     

Biogeography of prostrate-leaved geophytes in semi-arid South Africa: hypotheses on functionality

Nowhere is the species diversity of geophytes greater than in the five mediterranean-climate ecosystems of the world. Of these, the Cape mediterranean zone of South Africa is the most speciose. While the relative diversity and importance of geophytes of all of the other four mediterranean regions of the world drops off sharply as one moves into adjacent winter-rainfall desert regions, geophytes in the semi-arid to arid Succulent Karoo (including Namaqualand) remain a very important component of the flora, both in terms of abundance and diversity (comprising 13 to 29% of the regional floras in this region). Apart from species richness, there are also a number of interesting geophyte growth forms in this region. One unusual growth form is geophytes with flattened leaves that lie prostrate on the soil surface. At least eight families (Amaryllidaceae, Colchicaceae, Eriospermaceae, Geraniaceae, Hyacinthaceae, Iridaceae, Orchidaceae and Oxalidaceae) exhibit this growth form. While this growth form is relatively common in many geophyte lineages in the Succulent Karoo biome and the Cape mediterranean zone (Fynbos biome), and occurs infrequently through the summer-rainfall temperate regions of Africa, it is virtually absent in other regions worldwide. A null hypothesis is that the prostrate leaved trait is a neutral characteristic, however biogeographical data do not support this. A neutral trait would be unlikely to show such a clear pattern of distribution. Several alternative hypotheses on the adaptive significance of this growth form are discussed. These include: avoidance of herbivory, reduction in competition from neighbors, creation of a CO₂ enriched environment below the leaves, reduction of water loss around the roots, reduction of water loss through transpiration, precipitation of dew on the leaves and maintenance of optimal leaf temperatures for growth.     

松辽盆地来D13井地层划分对比研究

岩石组合特征和同位素数据表明,松辽盆地来D13井137.0—142.0m井段属于早白垩世晚期(Aptian—Albian期)营城组。104.2—137.0m井段光山核桃粉(Caryapollenites simplex)-拟榛莫米粉(Momipites coryloides)-朴粉未定种(Celtispollenites sp.)-具缘铁杉粉(Tsugaepollenites igniculus)组合特征可以与前人的大安组孢粉组合特征对比,反映的都是暖温带至北亚热带中生气候,而与晚白垩世嫩江组的孢粉组合特征截然不同,应该确定为早中新世晚期至中中新世的大安组。54.2—104.2m井段小蒿粉(Artemisiaepollenites minor)-拟桦粉未定种(Betulaceoipollenites sp.)-枥粉未定种(Carpinipites sp.)-水龙骨单缝孢未定种(Polypodiaceaesporites sp.)组合特征可以与前人的泰康组孢粉组合特征对比,反映的都是暖温带至北亚热带中生偏旱气候,这与前人依据岩石组合特征确定为泰康组的结论一致,孢粉组合时代分析表明,该井段沉积的时间为晚中新世至上新世初期。研究结果丰富了松辽盆地新近纪孢粉地层学内容,为松辽盆地西部斜坡区井下新近纪孢粉地层学对比提供了新资料,也为邻区新近纪生物地层学对比以及古植被和古气候分析提供了新的依据。     

Biome stability predicts population structure of a southern African aridland bird species

Environments are heterogeneous in space and time, and the permeability of landscape and climatic barriers to gene flow may change over time. When barriers are present, they may start populations down the path toward speciation, but if they become permeable before the process of speciation is complete, populations may once more merge. In Southern Africa, aridland biomes play a central role in structuring the organization of biodiversity. These biomes were subject to substantial restructuring during Plio‐Pleistocene climatic fluctuations, and the imprint of this changing environment should leave genetic signatures on the species living there. Here, we investigate the role of adjacent aridland biome boundaries in structuring the genetic diversity within a widespread generalist bird, the Cape Robin‐chat (Cossypha caffra). We find evidence supporting a central role for aridland biomes in structuring populations across Southern Africa. Our findings support a scenario wherein populations were isolated in different biome refugia, due to separation by the exceptionally arid Nama Karoo biome. This biome barrier may have arisen through a combination of habitat instability and environmental unsuitability, and was highly unstable throughout the Plio‐Pleistocene. However, we also recovered a pattern of extensive contemporary gene flow and admixture across the Nama Karoo, potentially driven by the establishment of homesteads over the past 200 years. Thus, the barrier has become permeable, and populations are currently merging. This represents an instance where initial formation of a barrier to gene flow enabled population differentiation, with subsequent gene flow and the merging of populations after the barrier became permeable.     

Systematics and evolution of the Pan‐Alcidae (Aves,Charadriiformes)

Puffins, auks and their allies in the wing‐propelled diving seabird clade Pan‐Alcidae (Charadriiformes) have been proposed to be key pelagic indicators of faunal shifts in Northern Hemisphere oceans. However, most previous phylogenetic analyses of the clade have focused only on the 23 extant alcid species. Here we undertake a combined phylogenetic analysis of all previously published molecular sequence data (～ 12 kb) and morphological data (n = 353 characters) with dense species level sampling that also includes 28 extinct taxa. We present a new estimate of the patterns of diversification in the clade based on divergence time estimates that include a previously vetted set of twelve fossil calibrations. The resultant time trees are also used in the evaluation of previously hypothesized paleoclimatic drivers of pan‐alcid evolution. Our divergence dating results estimate the split of Alcidae from its sister taxon Stercorariidae during the late Eocene (～ 35 Ma), an evolutionary hypothesis for clade origination that agrees with the fossil record and that does not require the inference of extensive ghost lineages. The extant dovekie Alle alle is identified as the sole extant member of a clade including four extinct Miocene species. Furthermore, whereas an Uria + Alle clade has been previously recovered from molecular analyses, the extinct diversity of closely related Miocepphus species yields morphological support for this clade. Our results suggest that extant alcid diversity is a function of Miocene diversification and differential extinction at the Pliocene–Pleistocene boundary. The relative timing of the Middle Miocene climatic optimum and the Pliocene–Pleistocene climatic transition and major diversification and extinction events in Pan‐Alcidae, respectively, are consistent with a potential link between major paleoclimatic events and pan‐alcid cladogenesis.     

Horizontal and elevational phylogeographic patterns of Himalayan and Southeast Asian forest passerines (Aves: Passeriformes)

Aim Zoogeographic patterns in the Himalayas and their neighbouring Southeast Asian mountain ranges include elevational parapatry and ecological segregation, particularly among passerine bird species. We estimate timings of lineage splits among close relatives from the north Palaearctic, the Sino‐Himalayan mountain forests and from adjacent Southeast Asia. We also compare phylogeographic affinities and timing of radiation among members of avian communities from different elevational belts. Location East Asia. Methods We reconstructed molecular phylogenies based on a mitochondrial marker (cytochrome b) and multilocus data sets for seven passerine groups: Aegithalidae, Certhiidae (Certhia), Fringillidae (Pyrrhula), Paridae (Periparus), Phylloscopidae, Regulidae and Timaliidae (Garrulax sensu lato). Molecular dating was carried out using a Bayesian approach applying a relaxed clock in beast . Time estimates were inferred from three independent calibrations based on either a fixed mean substitution rate or fixed node ages. The biogeographic history of each group was reconstructed using a parsimony‐based approach. Results Passerine radiation in Southeast Asia can be divided into roughly three major phases of separation events. We infer that an initial Miocene radiation within the Southeast Asian region included invasions of (sub)tropical faunal elements from the Indo‐Burmese region to the Himalayan foothills and further successive invasions to Central Asia and Taiwan towards the early Pliocene. During two further Pliocene/Pleistocene phases, the subalpine mountain belt of the Sino‐Himalayas was initially invaded by boreal species with clear phylogenetic affinities to the north Palaearctic taiga belt. Most terminal splits between boreal Himalayan/Chinese sister taxa were dated to the Pleistocene. Main conclusions Extant patterns of elevational parapatry and faunal transition in the Sino‐Himalayas originated from successive invasions from different climatic regions. The initiation of Southeast Asian passerine diversification and colonization of the Himalayan foothills in the mid‐Miocene coincides with the postulated onset of Asian monsoon climate and the resulting floral and faunal turnovers. Patterns of elevational parapatry were established by southward invasions of boreal avifaunal elements to the subalpine Sino‐Himalayan forest belt that were strongly connected to climate cooling towards the end of the Pliocene. Current patterns of allopatry and parapatry in boreal species (groups) were shaped through Pleistocene forest fragmentation in East Asia.     

A biogeographical assessment of anthropogenic threats to areas where different frog breeding groups occur in South Africa: implications for anuran conservation

Aim To determine the spatial relationship between areas where different frog breeding groups occur and elevated anthropogenic activities, and the conservation implications thereof. Location South Africa. Methods Data on frog distribution ranges for the southern African sub‐region were used to identify biogeographical areas within South Africa. A random draw technique was used to determine whether areas where different frog breeding groups occur were characterized by higher levels of anthropogenic threats than expected by chance. Four measures (human population density, percentage land transformation, percentage protected area and invasive alien plants richness) expected to reflect threats were analysed. Results Terrestrial‐breeders were more often spatially associated with areas of threat than expected by chance in three of the seven biogeographical regions examined with land transformation and invasive alien plant richness being most significant. The south central was the only region where terrestrial‐breeders were spatially congruent with protected areas. Areas where stream‐breeders occur were spatially congruent with anthropogenic threats (with alien plants being most consistent) in five of the seven regions examined while protected areas were well represented in four of the seven regions. Non‐significant results were found for permanent and temporary aquatic‐breeders at both the national and the biogeographical scale. Main conclusions By analysing data at the sub‐continental scale we were able to identify regional threats to amphibians traditionally classified at species‐specific scales. Our study recognized land transformation and alien invasive plants as significant threats to areas important for the long‐term breeding success of stream and terrestrial amphibians in South Africa. Areas where different breeding groups occur in the south‐western Cape showed the greatest spatial congruence with the threats examined. Areas where terrestrial breeding frogs occur are not well represented in the current conservation network. This has important implications in addressing the current status of threats on amphibians in a biogeographical context.     

Late Pliocene vegetation and climate of Zhangcun region,Shanxi, North China

To understand the Neogene climatic changes in eastern Asia and evaluate the intercontinental climatic differences, we have quantitatively reconstructed the vegetation successions and climatic changes in the late Pliocene Zhangcun area based on the palynological data and explored the regional climatic differences between central Europe and eastern Asia. The late Pliocene palynological assemblage of Zhangcun, Shanxi was composed of 63 palynomorphs, belonging to 50 families, covering angiosperms (90.2%), gymnosperms (9.7%), ferns (0.09%), and other elements (0.02%). Four periods of vegetation succession over time were recognized. In period 1, a needle‐ and broad‐leaved mixed forest prevailed with a cool and dry climate. Period 2 was characterized by an expansion of forest with a warmer and wetter climate. The number of conifers increased and that of herbs decreased in period 3, and the climate became cool and dry. In period 4, the forest was dominated by conifers and reflecting a cooler climate. The data of seven climatic parameters in general and four periods estimated by the Coexistence Approach suggested that (1) The late Pliocene temperatures and precipitations were higher than today. (2) The Neogene climate of both Central Europe and North China exhibited a general cooling and drying trend although the mean annual temperature dropped by ca. 1 °C in North China, vs. ca. 7 °C in Central Europe from the middle Miocene to the late Pliocene. (3) The decline of the mean maximum monthly precipitation might signal a weakening of the summer monsoon. (4) The decline of both the mean coldest monthly temperature and the mean minimum monthly precipitation might be linked to the strengthening of the winter monsoon in eastern Asia. (5) The rapid uplift of the Tibetan Plateau strengthened the climatic cooling and drying during the late Pliocene of the Zhangcun region.     

Cape diversification and repeated out-of-southern-Africa dispersal in paper daisies (Asteraceae-Gnaphalieae)

The large daisy tribe Gnaphalieae occurs in extra-tropical habitats worldwide, but is most diverse in southern Africa and in Australia. We explore the age and evolutionary history of the tribe by means of a phylogenetic hypothesis based on Bayesian analysis of plastid and nuclear DNA sequences, maximum likelihood reconstruction of ancestral areas, and relaxed Bayesian dating. Early diversification occurred in southern Africa in the Eocene-Oligocene, resulting in a grade of mostly Cape-centred lineages which subsequently began speciating in the Miocene, consistent with diversification times for many Cape groups. Gnaphalieae from other geographic regions are embedded within a southern African paraphylum, indicating multiple dispersals out of southern Africa since the Oligocene to Miocene which established the tribe in the rest of the world. Colonisation of Australia via direct long-distance trans-oceanic dispersal in the Miocene resulted in the radiation which produced the Australasian gnaphalioid flora. The similarly diverse regional gnaphalioid floras of Australasia and southern Africa thus exhibit very different temporal species accumulation histories. An examination of the timing and direction of trans-Indian Ocean dispersal events in other angiosperms suggests a role for the West Wind Drift in long-distance dispersal eastwards from southern Africa.     

Climatic fluctuations shape the phylogeography of a mesic direct‐developing frog from the south‐western Australian biodiversity hotspot

Aim To assess phylogeographic pattern throughout the range of Metacrinia nichollsi in order to develop specific biogeographical hypotheses for the wet forests of south‐western Australia. This was carried out by contrasting a direct‐developing frog species, M. nichollsi, that breeds independently of free surface water with conventional, aquatic breeders and highly specialized direct developers. Location Wet forests of the south‐western Australian biodiversity hotspot – an area of high species richness and endemism for myobatrachid frogs and many other faunal groups. Methods We compiled an extensive phylogeographic data set from field‐collected samples based on mitochondrial ND2 sequences. Phylogenetic analyses combined with estimates of divergence times were used to build a model of major biogeographical events affecting the species. Phylogeographic analyses were used to provide insights into smaller‐scale processes acting within each major lineage. Results Phylogenetic analysis recovered three major lineages, with divergence dates coincident with late Miocene–early Pliocene arid cycles. One lineage was confined to geographically isolated populations in the Stirling Ranges (Stirling Ranges Lineage, SRL). The continuous range of M. nichollsi was split into two: the Main Range Lineage (MRL) and the Southern Coastal Lineage (SCL). The SCL displays a strong drainage‐based population structure, whereas the MRL displays a strong signature of recent expansion, suggesting that these two lineages have had very different biogeographical histories. Main conclusions Late Miocene–Pliocene aridity appears to have isolated populations in the Stirling Ranges and resulted in the formation of two additional lineages on a north–south gradient that are independent of southward‐flowing drainage systems. Our results demonstrate that climatic fluctuations are likely to have generated fine‐scale phylogeographic structure within M. nichollsi and that catchment regions are important refugia during arid cycles.     

Pliocene Atlantic molluscan assemblages from the Mondego Basin (Portugal): Age and palaeoceanographic implications

The Pliocene molluscan assemblage from the Mondego Basin (Portugal, Western Iberia) plays a particularly important role in the understanding of the palaeobiogeography of Neogene–Quaternary molluscs of the Atlantic Frontage of Europe and the western Mediterranean. The importance of these Portuguese molluscan deposits is stressed, as it is the only assemblage representative of the southern portion of the Pliocene French–Iberian biogeographical Province.The Pliocene marine fossiliferous deposits of the Mondego Basin (central-west Portugal) are dated using their nannofossil and molluscan assemblages, as well as Strontium dating. The results suggest a late Zanclean to early Piacenzian age. Chronologically they are equivalent to the Mediterranean Pliocene Molluscan Unit 1 (MPMU1). However, due to the more northern geographical location of the Mondego Basin assemblages, their molluscan content is closer to that of MPMU2 than to that of MPMU1 in the Mediterranean.The presence of a stock of thermophilic taxa in the Mondego assemblage, no longer existent in European waters, enabled us to suggest a palaeoenvironmental reconstruction for mid-Pliocene SSTs in the region. We put forward the hypothesis that the SSTs at the latitude of Mondego, during late Zanclean to early Piacenzian, would be characterized by a yearly SST pattern analogous to that of present-day Cape Blanc (West Africa). Consequently, whilst subtropical conditions existed in the Atlantic Zanclean to mid-Piacenzian at Mondego latitude in the Mediterranean fully tropical conditions prevailed at that time. The Mondego SST estimates correlate with those estimated for MPMU2 in the Mediterranean.The global palaeoenvironmental reconstruction of mid-Pliocene SSTs in the PRISM2 Project suggests, for western Iberia, at Mondego latitude, an August SST of about 23 °C, and a February temperature of about 17 to 18 °C. Our hypothesis suggests similar August SST differing in only half a degree Celsius (23.5 vs. 23 °C) and February SSTs slightly higher (19 vs. 17–18 °C).     

Explaining disparities in species richness between Mediterranean floristic regions: a case study in Gladiolus (Iridaceae)

Aim The causes of geographical variation in species richness in clades that do not follow the latitudinal diversity gradient have rarely been investigated. Here, we examine spatial asymmetries of diversity in Gladiolus (Iridaceae), a large genus (> 260 species) that is present in two mediterranean climate biomes: the Cape of southern Africa (106 species) and the Mediterranean Basin (7 species). Despite convergence of climatic conditions between the two regions, the species density of Gladiolus is over one order of magnitude higher in the Cape than in the Mediterranean Basin. We investigate whether the diversity disparities observed in the genus are better explained by recent colonization of species‐poor areas (temporal hypothesis) or by differential rates of diversification (evolutionary hypothesis). Location Africa, Madagascar and Eurasia Methods We employ a recently developed Bayesian method for the estimation of diversification rates and a biogeographical optimization approach within a phylogenetic framework. Results In Gladiolus, the ‘diversity anomaly’ between the two Mediterranean climate regions cannot be explained solely by the time available for speciation in the Cape, but is also due to locally reduced rates of diversification in the Mediterranean Basin. Furthermore, high overall diversity in southern Africa stems from an ancient origin in the Cape allied with high rates of diversification in the summer‐rainfall region of the subcontinent. Main conclusions Both evolutionary and temporal hypotheses must be taken into account in order to explain the diversity anomaly between the Mediterranean Basin and the Cape. Our results suggest that regions at comparable latitudes and/or with similar climate may not converge in diversity levels due to heterogeneity of diversification rates and contrasting biogeographical histories.     

Time of diversification in the Cape fauna endemisms,inferred by phylogenetic studies of the genus Iselma (Coleoptera: Meloidae: Eleticinae)

The endemic diversification of the Cape zone fauna and the phylogenetic relationships among the 30 species of the blister beetle genus Iselma are investigated. We analysed morphological, molecular (mtDNA 16S) and combined datasets of characters using a number of approaches (maximum parsimony, maximum likelihood, Bayesian inference analyses). We propose hypotheses of diversification times among taxa from molecular clock analyses. Morphological and molecular analyses produced similar results. According to maximum likelihood molecular studies, radiation within the genus Iselma occurred during the Pliocene and Pleistocene, roughly contemporaneously with the shift in African climate, vegetation and faunal assemblages. Two main lineages, one Namibian and one South African, separated c. 4.9 Ma. Within the South African lineage we identify two groups of endemic species, one in Little Karoo and one that extend towards southern Namaqualand. The remaining South African groups of species are spread through Namaqualand and the southwestern Cape area. These include several endemisms, with different times of diversification during the Pleistocene, probably related in part to glacial cycles. These endemisms are distributed in small areas of the following ecosystems: coastal Strandveld, Succulent Karoo and particularly Fynbos.     

Out of Africa: biogeographic history of the open‐habitat chats (Aves,Muscicapidae: Saxicolinae) across arid areas of the old world

Arid and semi‐arid areas constitute a prominent feature of the earth today, especially in Asia and Africa. Their formation started in the middle Miocene with increased stepwise aridification since the Pliocene. This aridification had strong ecological and evolutionary consequences and not only led to fragmentation of moist‐adapted biota, but also fostered the evolution of arid‐adapted taxa from mesic ancestors and triggered speciation within arid areas. The open‐habitat chats, a clade within Saxicolinae (Aves, Muscicapidae), constitute one of the most significant arid‐adapted passerine groups of Africa and Eurasia. Here, we present a temporal and spatial framework for the diversification of open‐habitat chats, using probabilistic approaches for the reconstruction of their biogeographic history based on a time‐calibrated multilocus molecular phylogenetic hypothesis. The diversification of open‐habitat chats was initiated in the late Miocene at around 7.4 Ma, most likely in sub‐Saharan Africa. Southern Africa and the Horn of Africa acted as centres of diversification and biogeographic expansion. From the latter area, the Arabo‐Sindic region and subsequently further parts of Eurasia and North Africa were colonized. The colonization history out of sub‐Saharan Africa contrasts with that of several other songbird clades, where a biogeographic expansion from Eurasia or northern Africa to southern Africa was prevalent. Habitat fragmentation through forest expansions during intermittent wetter periods in Africa influenced diversification in several clades. However, phases of increased aridity, with hyperarid regions acting as drivers of vicariance, seem to have also been important in radiations of the Arabo‐Sindic region and the Horn of Africa during the Pleistocene. Different processes such as colonization of new areas followed by vicariance or speciation across ecotones might have played a role throughout the radiation of open‐habitat chats.