Carolinea 76

Carolinea 76 (2018): 35-55, 28 Abb.; Karlsruhe, 14.12.2018 35 A sketch of the lichen biota in a Renosterveld vegetation habitat V olkmar W irth , H arrie J. M. S ipman & O dette C urtis -S cott Abstract A sketch of the lichen vegetation of the Haarwegskloof Renosterveld Reserve near Bredasdorp (Western Cape, South Africa) is presented . This reserve is a re- presentative example of renosterveld vegetation, which replaces the better known fynbos in relatively dry regi- ons on more fertile, clay- and shale-based soils. Our sketch is a first attempt to characterize the lichen biota of a renosterveld area. The rather low number of 76 en- countered species reflects the absence of aged trees and large rock formations and occasional bushfires. However, the significance of the species is great becau- se most have very restricted distributions in southern Africa. Among the epiphytic lichens Physciaceae and Xanthoria -relatives prevail, while on soil and on rock the genus Xanthoparmelia is by far the most important, with 22 species, among them several endemics. Kurzfassung Eine Skizze der Flechtenbiota in einem Renosterveld-Habitat. Die Flechtenvegetation des Haarwegskloof Renoster- veld Reserve bei Bredasdorp (Western Cape, Südafri- ka) wird skizziert als ein Beispiel für die Flechtenbiota in der Renosterveld-Vegetation, welche gegenüber dem auf sauren, nährstoffarmen Böden wachsenden Fyn- bos auf relativnährstoffreichen Ton- und Schieferbö- den und in trockeneren Gebieten vorkommt. Mit dieser Artenliste wird erstmals die Flechtenvegetation eines Renosterveld-Gebietes charakterisiert. Die nicht sehr hohe Zahl von 76 registrierten Arten spiegelt das Feh- len von älteren Bäumen und größeren Felsbildungen sowie Brandereignisse wider. Dem gegenüber steht die flechtengeographische Bedeutung der Arten, de- ren Verbreitung zu einem großen Teil auf das südlich- ste Afrika beschränkt ist. Unter den auf Sträuchern wachsenden Epiphyten herrschen Physciaceae und Xanthoria -Verwandte vor, unter den boden- und ge- steinsbewohnenden Flechten Arten der Gattung Xan­ thoparmelia , von der 22 Arten gefunden wurden. Authors Prof. Dr. V olkmar W irth , Friedrich-Ebert-Straße 68, D-71711 Murr, Germany; E-Mail: volkmar.wirth@online.de Dr. H arrie J. M. S ipman , Freie Universität, Botanischer Garten und Botanisches Museum, Königin-Luise-Stra- ße 6-8, D-14195 Berlin, Germany; E-Mail: H.Sipman@bgbm.org Dr. O dette C urtis -S cott , Overberg Lowlands Con- servation Trust, 3 de Kock street, 7170 Napier, South Africa; E-Mail: info@overbergrenosterveld.org.za 1 Introduction The Cape Floristic Region (CFR) in the southern- most region of South Africa is recognized as one of the World’s 34 Biodiversity Hotspots ( M yers 1990, M yers 2003), is the richest of the World’s six Floral Kingdoms (with over 9000 species) and is significantly threatened by a plethora of issues, including infestations by exotic invasive plants, transformation for development and agri- culture and general habitat degradation associa- ted with mismanagement ( R ebelo 1992, R ouget et al. 2003, R aimondo et al. 2009).Within the CFR are two main Biomes: the Karoo and the Fynbos Biomes. Within these Biomes are over 120 dif- ferent vegetation types. ‘True’ fynbos vegetation tends to be concentrated in mountainous and coastal regions within the CFR and is generally associated with poor, acidic, sandy soils. Fynbos vegetation types are typified by a dominance of proteas, ericas (heather) and restios (reeds) and are fire-adapted and fire-dependent systems. However, in the lowlands of the CFR, vegetation typically changes to renosterveld, in response to interactions between lower rainfall and a change to relatively more fertile, clay- and shale-based soils. Renosterveld is typified by the absence of the three main ‘fynbos indicators’ (proteas, ericas and restios) and tends to be dominated by Aster- aceous shrubs (i.e. woody shrubs belonging to the daisy family) and perennial C 3 and C 4 gras- ses. Compared with adjacent fynbos habitats, reno- sterveld tends to have an overall grey appea- rance, due to the dominance of asteraceous shrubs and in particular, the renosterbos Elytro­ pappus rhinocerotis . It is also a grassier habitat and is richer in forbs, annuals and geophytes than fynbos habitats ( R ebelo 1992). Renoster- veld is renowned for its exceptionally high levels of geophyte diversity ( C owling 1983, P aterson - J ones 1998). Lowland renosterveld vegetation types have been severely transformed, with > 90 % of them having been ploughed for agricultural develop- ment ( K emper et al. 1999, M c D owell & M oll 1992). According to the S anbi & D eat ’s (2009)