The term “inselberg” (from German Insel = island and Berg = mountain) has been invented by the German geologist Wilhelm Bornhardt in 1900. Inselbergs are old landscape elements (with an age of millions of years) that occur on crystalline shields of all continents. They are mainly granitic or gneissic rock outcrops that rise more or less abrupt above their surroundings. Frequently they are dome-shaped and possess steep slopes consisting of bare rock.
Despite being characterized by extreme environmental conditions (e.g. high temperatures, lack of water), inselbergs harbour a surprising richness of plant communities. Typically their vegetation is clearly demarcated from that of the surroundings. The large expanses of open rocky slopes are covered by cryptogamic crusts consisting of cyanobacteria and lichens. Other habitat types and plant communities are e.g. monocotyledonous mats, shallow depressions, rock pools and ephemeral flush vegetation. Inselbergs in the tropics (e.g. in Brazil and Madagascar) are characterized by high numbers of plant species and local endemics. They form centers of diversity for highly specialized life forms such as carnivorous and desiccation-tolerant plants. Whereas our floristic knowledge about inselbergs in parts of Africa (e.g. Côte d’Ivoire), South America (e.g. southeastern Brazil) and Australia is relatively good, there are still many regions and countries (e.g. Angola, India) which are rich in inselbergs but from where almost no data are available
Wilhelm Barthlott and Stefan Porembski (both at the University of Bonn) have started botanical work on inselbergs in 1990 in West Africa (Côte d’Ivoire) which was supported by the German Research Foundation (DFG). Surprisingly little was known about the floristics and ecology of Ivorian inselbergs and during the following decade profound insights into their major plant communities, life-forms (in particular desiccation-tolerance) and various other botanical aspects were gained. In addition, PhD-students (Rüdiger Seine, Uwe Becker, Andreas Gröger) were part of our group which provided detailed data from East Africa (Zimbabwe) and South America (Venezuela).
Stefan Porembski moved to Rostock in 1998 and since then inselberg research conducted by him continued in West Africa. Moreover, studies about the flora and vegetation of inselbergs in other parts of Gondwana were started: a “Gondwanan Gang” of inselberg research was created. Current research from our team at University of Rostock focuses on Madagascar (in cooperation with Missouri Botanical Garden) and Brazil (in cooperation with Universidade Federal de Minas Gerais, Universidade Estadual Paulista, Jardim Botanico do Rio de Janeiro). At the moment, a Brazilian student, Luiza de Paula, is developing her PhD project at University of Rostock, conducting studies on inselbergs in southeastern Brazil, which deal with patterns of species diversity on these rock outcrops.
Furthermore, using the desiccation-tolerant Velloziaceae as an example, Juliane Rexroth works in Madagascar with species of Xerophyta concerning aspects of population differentiation applying molecular techniques. Already during our first studies in West Africa it became clear that inselbergs possess links with other types of rock outcrops. For example, it became clear that certain plant species that are adapted to prolonged periods of drought are shared between inselbergs, ferricretes and sandstone outcrops. In order to understand the links between the various types of rock outcrops we intend to bring together rock outcrop researchers from different geographic regions and disciplines.
Many parts of the peninsular India are composed of ancient crystalline basement rocks, predominantly of granite and gneiss. The geomorphological spectrum of granitic and gneissic inselbergs is impressive and includes large monoliths, shield-like outcrops and bolder strewn koppjes. Monolithic outcrops are typical for humid regions (e.g. Kerala), in contrast to koppjes which dominate vast stretches in the drier parts of India (e.g. in Andra Pradesh). Due to the widespread occurrence of granitic and gneissic outcrops India has one of the world’s largest quarrying industries and is one of the most important suppliers of rocks for constructions. For instance, the spectrum of different coloured granites is breathtaking and is expressed by names such as “Black Granite”, “Chilly Red” or “Magadi Pink”.
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Members
Prof. Dr. Stefan Porembski
Inselberg research has been carried out by Prof. Dr. Stefan Porembski since 1990. He has concentrated his studies on the vegetation of African, Malagasy and South American inselbergs. He has a particular interest in desiccation-tolerant and carnivorous plants.
M.Sc. Luiza F. A. de Paula
Luiza de Paula holds a Bachelor's degree in Biological Sciences from the Federal University of Minas Gerais, Brazil and a Master's Degree in Plant Biology from the same University. She is currently a PhD student at University of Rostock, Germany, under the supervision of Prof. Dr. Stefan Porembski. She has experience with Botany and Ecology, with emphasis on floristics, functional and community ecology, working mainly with the flora of inselbergs (granitic and gneiss rock outcrops). Her PhD project deals with (1) patterns of species diversity on Brazilian inselbergs, with a focus on monocotyledonous mats, and (2) studies on the population genetics of Vellozia plicata, a widespread species on Brazilian inselbergs.
M.Sc. Juliane Rexroth
University of Rostock
Institute of Biosciences
Department of Botany and Botanical Garden
M.Sc. Julius Köhler
University of Rostock
Institute of Biosciences
Department of Botany and Botanical Garden
Partners
India:
Aparna Watwe (Tata Institute of Social Sciences)
Madagascar:
Marina Rabarimanarivo (Missouri Botanical Garden)
Australia:
Steve Hopper (University of Western Australia)
Brazil:
Fernando A.O. Silveira (Universidade Federal de Minas Gerais)
Joao Renato Stehmann (Universidade Federal de Minas Gerais)
Rafaela C. Forzza (Jardim Botanico do Rio de Janeiro)
Clarisse Palma-Silva (Universidade Estadual Paulista)
Luana P. Mauad (Jardim Botanico do Rio de Janeiro)
Belgium:
Bram Vanschoenwinkel (Vrije Universiteit Brussel)
Côte d'Ivoire:
Annick Koulibaly (Université Jean Lorougnon Guédé)