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Lichens are the object of investigation within the framework of the BIOTA Southern Africa project, subproject S04 (http://www.biota-africa.org). This interdisciplinary research project, installed in 2000, focuses on the analysis of biodiversity and its changes along climatic and vegetation gradients (transects) in Namibia and in the Republic of South Africa. In the context of this project, studies on the diversity of lichens are carriedout. Special reference is given to the monitoring of lichens growing on soil, which form the so called biological soil crusts.Lichen diversity is assessed and analysed with respect to its spatial and temporal changes. These are related to various abioticand biotic factors such as climate, soil features and land use. The indicator value of certain terricolouslichen taxaand/or lichen groups (communities) is investigated for the study area, and it is intended to use itin a future long-term monitoring programme in the region. In this brochure, we whish to explain what lichens are, how do they live and where do they grow, and why they are so important as bioindicatorsin arid and semi-arid areas of the world. The activities of the S04 subproject along the BIOTA transect are described, as well as the methods used for monitoring environmental changes in Southern Africa using soil-inhabiting lichens.
Fourteen new species of the Colletes fasciatus species group are described, all of them endemic to the winter rainfall area in South Africa: C. ascopalis sp. nov. ♀, C. carolinae sp. nov. ♀♂, C. cedarbergensis sp. nov. ♀, C. fabiani sp. nov. ♀♂, C. fuscitergus sp. nov. ♂, C. khoisanorum sp. nov. ♀, C. kogelbergensis sp. nov. ♀♂, C. littoralis sp. nov. ♀, C. longitarsus sp. nov. ♂, C. peerboomi sp. nov. ♀, C. richtersveldensis sp. nov. ♀, C. ruschia sp. nov. ♀♂, C. spinipes sp. nov. ♂, C. troetroeensis sp. nov. ♀. Two species are synonymized based on newly recognized sex associations: C. katharinae Kuhlmann, 2007 syn. nov. is synonymized with C. infracognitus Cockerell, 1937 and C. bokkeveldi Kuhlmann, 2007 syn. nov. with C. zygophyllum Kuhlmann, 2007. The previously unknown female of C. inornatus Cockerell, 1946 is described for the first time and new records of already described species are added. All of the currently known 37 species of the C. fasciatus-group are imaged and included in a key to facilitate their identification.
Highlights
• Northern and eastern grassland-savanna boundary defined by minimum temperature.
• Dynamics of fire, frost and growing season temperatures combine to produce this limit.
• Western limit is related to moisture availability.
• Modern, high-resolution climate data enables refinement of bioclimatic limits.
• Reparameterisation improves global model performance at regional scale.
Abstract
Understanding the controls of biome distributions is crucial for assessing terrestrial ecosystem functioning and its response to climate change. We analysed to what extent differences in climate factors (minimum temperatures, water availability, and growing season temperatures (degree days above 5 °C (GDD5)) might explain the poorly understood borders between grasslands, savannas and shrublands in eastern South Africa. The results were used to improve bioclimatic limits in the dynamic global vegetation model (DGVM) LPJ-GUESS. The vegetation model was also used to explore the role of fire in the biome borders. Results show no clear differences between the adjacent biomes in water availability. Treeless grasslands primarily occur in areas with minimum temperatures and GDD5 values below that of savannas. The standard fire module in LPJ-GUESS is not able to reproduce observed burned area patterns in the study region, but simulations with prescribed fire return intervals show that a combination of low temperatures and fire can explain the treeless state of the grassland biome. These results confirm earlier hypotheses that a combination of low winter temperatures, causing frost damage to trees, and low growing season temperatures that impede tree sapling growth and recruitment, particularly under re-occurring fires, drive the grassland-savanna border. With these insights implemented, the LPJ-GUESS simulation results substantially improved grass distribution in the grassland biome, but challenges remain concerning the grassland-shrubland boundary, tree-grass competition and prognostic fire modelling.
The nitidus species group of the bee genus Scrapter Lepeletier & Serville, 1828 is redefi ned, revised and 15 species are described as new for science: S.caeruleus sp. nov. ♀, S.confusus sp. nov. ♀♂, S.convexoides sp. nov. ♂, S. convexus sp. nov. ♀♂, S. crassipunctatus sp. nov. ♀♂, S.felicis sp. nov. ♀♂, S.fl avipunctatus sp. nov. ♀♂, S.imparilis sp. nov. ♀♂, S. littoralis sp. nov. ♀, S.longicornis sp. nov. ♂, S.montanus sp. nov. ♀♂, S.mpumalangensis sp. nov. ♀♂, S.obtusus sp. nov. ♀♂, S. perpunctatulus sp. nov. ♂ and S.variabilis sp. nov. ♀♂. The previously unknown males of S. divergens (Friese, 1925), S. semirufus Cockerell, 1932 and S. perpunctatus Cockerell, 1933 are described for the fi rst time. All currently known 28 species of the S. nitidus species group are redescribed, imaged and included in a key to facilitate their identifi cation.
A new species of Fidelia Friese, 1899 is described from southern Africa: Fidelia (Fideliopsis) whiteheadi Litman & Kuhlmann sp. nov. Diagnostic characters are provided to distinguish this species from others in the genus, particularly from the closely related F. hessei; an updated description for Fidelia hessei is also given. The host plant preferences and seasonal activity of F. whiteheadi Litman & Kuhlmann sp. nov. and F. hessei are discussed. Finally, a revised, illustrated key to species of the genus Fidelia is presented.
Nine new species of the South African endemic group of euryglossiform bees of the genus Scrapter Lepeletier & Serville, 1828 are described, thus bringing the total number of species to 29 in this species-group: Scrapter avontuurensis Kuhlmann sp. nov. ♀, S. bokkeveldensis Kuhlmann sp. nov. ♀, S. fynbosensis Kuhlmann sp. nov. ♀, S. hergi Kuhlmann sp. nov. ♂, S. keiskiensis Kuhlmann sp. nov. ♀, S. mellonholgeri Kuhlmann sp. nov. ♀♂, S. nitens Kuhlmann sp. nov. ♀, S. oubergensis Kuhlmann sp. nov. ♀ and S. willemstrydomi Kuhlmann sp. nov. ♂. The new replacement name S. punctulatus nom. nov. is proposed for S. punctatus Kuhlmann, 2014 which is a junior primary homonym of S. punctatus Lepeletier & Audinet-Serville, 1825 (= Allodape punctata [Lepeletier & Audinet-Serville, 1825]). Moreover, new records for already described taxa are presented and an updated key to all species of euryglossiform Scrapter is provided.
The South African endemic bees of the "euryglossiform" species of the genus Scrapter Lepeletier & Serville, 1828 are revised and illustrated. The species-group is defined for the first time and comprises 20 species, 16 of which are described here as new: Scrapter exiguus sp. nov. ♀, ♂, S. gessorum sp. nov. ♀, S. inexpectatus sp. nov. ♀, S. luteistigma sp. nov. ♀, ♂, S. minutissimus sp. nov. ♂, S. minutuloides sp. nov. ♀, S. minutus sp. nov. ♀, S. nanus sp. nov. ♀, ♂, S. nigerrimus sp. nov. ♀, S. nigritarsis sp. nov. ♀, S. papkuilsi sp. nov. ♀, ♂, S. punctatus sp. nov. ♀, ♂, S. pygmaeus sp. nov. ♀, S. roggeveldi sp. nov. ♀, ♂, S. spinipes sp. nov. ♀, ♂ and S. ulrikae sp. nov. ♀, ♂. For S. acanthophorus Davies, 2005 and S. sittybon Davies, 2005 the female is here described for the first time. A key to all species is provided.
The South African endemic bee genus Redivivoides Michener, 1981 is revised and redefined. The genus comprises seven species, six of which are described here as new: Redivivoides capensis sp. nov. ♀♂, R. eardleyi sp. nov. ♀, R. kamieskroonensis sp. nov. ♀, R. karooensis sp. nov. ♀♂, R. namaquaensis sp. nov. ♀♂ and R. variabilis sp. nov. ♀♂. A key to species is provided.
Die vorliegende Arbeit beschäftigt sich mit der geochemischen und isotopischen Analyse detritischer Zirkonminerale aus rezenten Sedimenten des weit verzweigten Orange- und Vaal River Flusssystems in Südafrika. Zirkone kristallisieren überwiegend aus krustalen Schmelzen und sind äußerst resistent gegenüber jeglicher Zerstörung und damit ein idealer Kandidat zur Rekonstruktion früherer Krustenbildungsprozesse der geologischen Erdgeschichte. Der kombinierte Ansatz der U-Pb Altersdatierung, der Hf Isotopie und der Spurenelementgeochemie mittels Laserablation und des Einsatzes induktiv-gekoppelter Sektorfeld- und Multikollektormassenspektrometer ermöglicht es die krustale Wachstums- und Entwicklungsgeschichte des südafrikanischen Kratons zu erfassen. Die mehr als 1200 U-Pb Analysen der Zirkone weisen 4 tektonische Hauptphasen des südafrikanischen Kontinents nach: 1. die Panafrikanische Orogenese (0.5-0.7 Ga), 2. das Namaqua-Natal Faltengürtelorogen (1.0-1.3 Ga), 3. die Kheis Orogenese (1.8-2.0 Ga) und 4. die westliche Kaapvaal-Kratonisierung (2.9-3.2 Ga). Allerdings zeigt sich, dass die 13 Probenlokationen überwiegend lokale bzw. regionale U-Pb Altersdaten ihrer umgebenden Herkunftsgebiete liefern. Die Hf Isotopie der Zirkone der verschiedenen tektonischen Hauptphasen Südafrikas stellen ihre differenzierte Akkretions- und Aufschmelzungsgeschichte dar. Die panafrikanischen Zirkone zeigen eine ausgeprägte Durchmischung von juvenilem und recyceltem Material. Die mesoproterozoischen (Namaquan) Zirkone entstanden aus juvenilem Magma während eines Inselbogen-Kontinent-Kollisionsereignisses. Die paläoproterozoischen und archaischen Zirkone sind Produkte von aufgeschmolzener prä-existierender kontinentaler Kruste oder vom Mantel abstammende Schmelzen, die durch kontinentale Kruste kontaminiert wurden. Die berechneten Hf Modellalter, so genannte „Mantelextraktionsalter" ergeben zwei Maxima, die zwei Stadien juvenilem Krustenwachstums einschließen, einmal vor 1.4 und 3.2 Ga. Dieses krustale Wachstum zeigt eine Übereinstimmung mit den progressiv episodischen Modellen von Nagler & Kramers (1998) sowie Condie (2000) mit Höhepunkten zwischen 3.0 und 2.0 Ga sowie den Studien von Wang et al. (2008) mit krustalen Wachstumsperioden von 1.6 bis 2.2 und 2.9 bis 3.4 Ga auf dem Nordamerikanischen Kontinent und auf dem Gondwana-Kontinent (Australien) von Hawkesworth & Kemp 2006) und implizieren wohl ein globales kontinentales Krustenwachstum. Die Abgrenzung und Wiedererkennung der Zirkone anhand der chemischen Zusammensetzung zu möglichen Muttergesteinen zeigen noch keine viel versprechenden Ergebnisse. Generell weisen die Zirkone eine magmatische granitoide Zusammensetzung kontinentalen Ursprungs auf. Eine Auffälligkeit stellen die erhöhten Spuren- und leichten Seltenenerdelemente in Zirkonen jeglicher Altersklassen dar. Nachfolgende Arbeiten müssen zeigen, wie und ob diese Anreicherungen Einfluss auf die chemische Zusammensetzung, die U-Pb Datierung und vor allem die Hf-Isotopie der Zirkone haben.
Ballomma, a new Afrotropical genus in the Cryptothelinae (Araneae, Zodariidae): eyes on the run
(2015)
Ballomma gen. nov. is described in the zodariid subfamily Cryptothelinae. It is characterized by the pairs of adjacent anterior median eyes and anterior lateral eyes and triangular palpal tarsus in the female, the concave tegulum with thin embolus in the male. Apart from the type species B. erasmus gen. et sp. nov. (♂♀), the genus contains B. haddadi gen. et sp. nov. (♂♀), B. neethlingi gen. et sp. nov. (♂♀), and B. legala gen. et sp. nov. (♀). A key to the species is provided. The restricted distribution of the genus is discussed.