Phytogeography of <i>Passerina</i> (Thymelaeaceae)

Passerina L. comprises 20 species and four subspecies of microphyllous. wind-pollinated shrubs. Once considered cosmopolitan, the genus as currently defined, is endemic to southern Africa. Endemism within the genus is highest in the Cape Floristic Region (CFR), where all members show morphological and anatomical adaptations to the winter rainfall and dry warm summers of the Mediterranean or semi-Mediterranean climate of the region. The Western Cape is the centre of diversity for Passerina, from where certain species extend to the west, north and east. The outlier populations of Passerina montana Thoday on the interior plateau of South Africa and Zimbabwe, as well as the Auas Moutains in Namibia, most probably originated in the CFR and formed part of a previously wider northern temperate Afromontane grassland-dominated vegetation during the Quartemary, of which relicts remained in the high mountain areas. P. burchellii Thoday and P. paludosa Thoday have the most restricted distribution and are regarded as Vulnerable. All other species are either widespread or under no immediate threat.

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The distribution of the dwarf succulent genus Conophytum N.E.Br. (Aizoaceae) in southern Africa

Bothalia ◽

10.4102/abc.v46i1.2019 ◽

2016 ◽

Vol 46 (1) ◽

Cited By ~ 8

Author(s):

Andrew J. Young ◽

Philip G. Desmet

Keyword(s):

Climate Change ◽

South Africa ◽

Southern Africa ◽

Conservation Planning ◽

Cape Floristic Region ◽

Geographical Range ◽

Western Cape ◽

Succulent Karoo ◽

Winter Rainfall ◽

Rainfall Region

Background: The dwarf succulent genus Conophytum N.E.Br. is one of the most species rich in the Aizoceae. The genus is most closely associated with a region of high floral endemism and biodiversity, the Succulent Karoo biome in south-western Africa.Objectives: To examine the distribution of Conophytum in south-western Namibia and in the Northern and Western Cape Provinces of South Africa.Method: A database comprising 2798 locality records representing all known species and subspecies of the genus Conophytum has been constructed.Results: The genus is primarily restricted to the arid winter-rainfall region of the Northern and Western Cape Provinces of South Africa and south-western Namibia, within the Greater Cape Floristic Region. Whilst taxa are found across all the main biomes in the region (the Succulent Karoo, Nama Karoo, Desert and Fynbos biomes), 94% of Conophytum taxa are found only in the Succulent Karoo biome and predominantly (88% of taxa) within South Africa. Endemism within specific bioregions is a feature of the genus and ~60% of taxa are endemic to the Succulent Karoo. Approximately 28% of all taxa could be considered point endemics. Whilst the genus has a relatively wide geographical range, we identify a pronounced centre of endemism in the southern Richtersveld.Conclusion: The genus Conophytum can be used as a good botanical model for studying patterns of diversity and speciation in the Succulent Karoo biome, the effects of climate change on dwarf succulents, and for informing conservation planning efforts.

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Karoo-fynbos biomass along an elevational gradient in the western Cape.

Bothalia ◽

10.4102/abc.v12i3.1818 ◽

1978 ◽

Vol 12 (3) ◽

pp. 555-560 ◽

Cited By ~ 13

Author(s):

M. C. Rutherford

Keyword(s):

Mediterranean Climate ◽

Elevational Gradient ◽

Total Biomass ◽

Western Cape ◽

Community Stability ◽

Succulent Karoo ◽

Winter Rainfall ◽

Dead Material ◽

Valid Comparison

A short characterization of the vegetational gradient from two basic physiognomic forms of fynbos, through Renosterbosveld to arid Karoo vegetation of the south-western Cape, is given with reference to possible vegetational analogues within similar gradients in winter-rainfall areas elsewhere. Description is limited to some aspects affecting biomass and its measurement, as well as to consideration of community stability needed for valid comparison of community biomass. Live individuals, including single dominant species, all other shrubs, graminoids and other herbaceous species as well as dead individuals were harvested separately in each major community type within an elevational gradient corresponding to the vegetational gradient described. Greatest biomass (14311 kg ha-1) was found in a summit restionaceous community, while lowest biomass (7564 kg ha-1) was found in a low-lying succulent Karoo community. There was an inverse relationship between elevation and percentage dead material mass and a strongly positive relationship between elevation and percentage biomass of the graminoid group. Total biomass values appear to be in keeping with available data for analogue communities in different Mediterranean climate areas, although distinct differences sometimes occur in the relative biomass contributions of component groups.

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Phylogeny, historical biogeography and divergence time estimates of the genus Colophon Gray (Coleoptera : Lucanidae)

Invertebrate Systematics ◽

10.1071/is13054 ◽

2014 ◽

Vol 28 (3) ◽

pp. 326 ◽

Cited By ~ 7

Author(s):

Angelika K. Switala ◽

Catherine L. Sole ◽

Clarke H. Scholtz

Keyword(s):

Divergence Time ◽

Cape Floristic Region ◽

High Mountain ◽

Western Cape ◽

Mitochondrial Coi ◽

Divergence Time Estimates ◽

Time Estimates ◽

Phylogenetic Status ◽

Early Paleocene ◽

Molecular Dataset

The flightless Cape High-mountain stag beetle genus Colophon (Coleoptera: Lucanidae) is studied. All species are endemic to the Cape Floristic Region of the Western Cape, South Africa. The study aimed to determine the specific and phylogenetic status of the described species of Colophon and to determine the main factors driving their evolution by testing the hypothesis of a lowland origin. This was achieved by analysing the mitochondrial COI, 16S rRNA and nuclear CAD genes, using a maximum likelihood and Bayesian approach. Timing of key biogeographical events in the diversification of Colophon was estimated in BEAST. The combined molecular dataset supports the described species. High genetic divergence was found between the described taxa. The mean estimated divergence of the genus was mid-Cretaceous, with a split into two lineages during the early Paleocene to mid Eocene. Species divergence was shown to have occurred during mid to late Miocene. Most species of Colophon showed an allopatric distribution, although contact zones between geographically adjacent species are likely. Climate seems to be the main driving factor behind Colophon evolution and the hypothesis of a lowland origin appears to be supported.

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Ecotoxicology of alpine streams in the West Carpathians—Alpine Bullhead (Cottus poecilopus) and high mountain flash flood effects

Environmental Science and Pollution Research ◽

10.1007/s11356-021-14157-1 ◽

2021 ◽

Author(s):

Martin Janiga ◽

Marián Janiga ◽

Martina Haas

Keyword(s):

Flash Flood ◽

High Mountain ◽

The West ◽

West Carpathians ◽

Alpine Streams ◽

Flood Effects ◽

Cottus Poecilopus

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Formation Patterns of Mediterranean High-Mountain Water-Bodies in Sierra-Nevada, SE Spain

Water ◽

10.3390/w13040438 ◽

2021 ◽

Vol 13 (4) ◽

pp. 438

Author(s):

Jose Luis Diaz-Hernandez ◽

Antonio Jose Herrera-Martinez

Keyword(s):

Sierra Nevada ◽

Unknown Origin ◽

Slope Instability ◽

Water Bodies ◽

High Mountain ◽

Mountain Areas ◽

Glacial Processes ◽

The Mediterranean ◽

Water Volumes

At present, there is a lack of detailed understanding on how the factors converging on water variables from mountain areas modify the quantity and quality of their watercourses, which are features determining these areas’ hydrological contribution to downstream regions. In order to remedy this situation to some extent, we studied the water-bodies of the western sector of the Sierra Nevada massif (Spain). Since thaw is a necessary but not sufficient contributor to the formation of these fragile water-bodies, we carried out field visits to identify their number, size and spatial distribution as well as their different modelling processes. The best-defined water-bodies were the result of glacial processes, such as overdeepening and moraine dams. These water-bodies are the highest in the massif (2918 m mean altitude), the largest and the deepest, making up 72% of the total. Another group is formed by hillside instability phenomena, which are very dynamic and are related to a variety of processes. The resulting water-bodies are irregular and located at lower altitudes (2842 m mean altitude), representing 25% of the total. The third group is the smallest (3%), with one subgroup formed by anthropic causes and another formed from unknown origin. It has recently been found that the Mediterranean and Atlantic watersheds of this massif are somewhat paradoxical in behaviour, since, despite its higher xericity, the Mediterranean watershed generally has higher water contents than the Atlantic. The overall cause of these discrepancies between watersheds is not connected to their formation processes. However, we found that the classification of water volumes by the manners of formation of their water-bodies is not coherent with the associated green fringes because of the anomalous behaviour of the water-bodies formed by moraine dams. This discrepancy is largely due to the passive role of the water retained in this type of water-body as it depends on the characteristics of its hollows. The water-bodies of Sierra Nevada close to the peak line (2918 m mean altitude) are therefore highly dependent on the glacial processes that created the hollows in which they are located. Slope instability created water-bodies mainly located at lower altitudes (2842 m mean altitude), representing tectonic weak zones or accumulation of debris, which are influenced by intense slope dynamics. These water-bodies are therefore more fragile, and their existence is probably more short-lived than that of bodies created under glacial conditions.

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Minimal clustering and species delimitation based on multi-locus alignments vs SNPs: the case of the Seriphium plumosum L. complex (Gnaphalieae: Asteraceae)

10.1101/2021.03.21.436318 ◽

2021 ◽

Author(s):

Zaynab Shaik ◽

Nicola Georgina Bergh ◽

Bengt Oxelman ◽

Anthony George Verboom

Keyword(s):

Species Delimitation ◽

Bayes Factor ◽

Cape Floristic Region ◽

Parametric Models ◽

Western Cape ◽

Nucleotide Polymorphisms ◽

Sequence Alignments ◽

Separate Species ◽

Multiple Sequence ◽

Data Set

We applied species delimitation methods based on the Multi-Species Coalescent (MSC) model to 500+ loci derived from genotyping-by-sequencing on the South African Seriphium plumosum (Asteraceae) species complex. The loci were represented either as multiple sequence alignments or single nucleotide polymorphisms (SNPs), and analysed by the STACEY and Bayes Factor Delimitation (BFD)/SNAPP methods, respectively. Both methods supported species taxonomies where virtually all of the 32 sampled individuals, each representing its own geographical population, were identified as separate species. Computational efforts required to achieve adequate mixing of MCMC chains were considerable, and the species/minimal cluster trees identified similar strongly supported clades in replicate runs. The resolution was, however, higher in the STACEY trees than in the SNAPP trees, which is consistent with the higher information content of full sequences. The computational efficiency, measured as effective sample sizes of likelihood and posterior estimates per time unit, was consistently higher for STACEY. A random subset of 56 alignments had similar resolution to the 524-locus SNP data set. The STRUCTURE-like sparse Non-negative Matrix Factorisation (sNMF) method was applied to six individuals from each of 48 geographical populations and 28023 SNPs. Significantly fewer (13) clusters were identified as optimal by this analysis compared to the MSC methods. The sNMF clusters correspond closely to clades consistently supported by MSC methods, and showed evidence of admixture, especially in the western Cape Floristic Region. We discuss the significance of these findings, and conclude that it is important to a priori consider the kind of species one wants to identify when using genome-scale data, the assumptions behind the parametric models applied, and the potential consequences of model violations may have.

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Trapping of Organochlorine Compounds in High Mountain Lakes

The Scientific World JOURNAL ◽

10.1100/tsw.2001.320 ◽

2001 ◽

Vol 1 ◽

pp. 609-611 ◽

Cited By ~ 1

Author(s):

Joan O. Grimalt ◽

Pilar Fernandez ◽

Rosa M. Vilanova

Keyword(s):

Atmospheric Transport ◽

Mountain Lakes ◽

Organochlorine Compounds ◽

High Mountain ◽

High Latitudes ◽

High Mountain Lakes ◽

Mountain Areas ◽

Persistent Pollutants

High mountain areas have recently been observed to be polluted by organochlorine compounds (OC) despite their isolation. These persistent pollutants arrive at these remote regions through atmospheric transport. However, the mechanisms involving the accumulation of these compounds from the atmospheric pool to the lacustrine systems still need to be elucidated. These mechanisms must be related to the processes involving the transfer of these pollutant from low to high latitudes[1] as described in the global distillation effect[2].

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