Floristic, biogeographical, and vegetational aspects of Pre-Cambrian rock outcrops (inselbergs) in eastern Bolivia

Floristics, structure and soil of insular vegetation in four quartzite-sandstone outcrops of "Chapada Diamantina", Northeast Brazil

“…Floristic patterns -Despite the regional variation between sites and the overall diversity found, the taxonomic entities of the studied flora largely resemble those of other rock outcrops in Brazil. For instance, the predominance of monocots confirms a well-known pattern for neotropical rock outcrops (Ibisch et al 1995, Meirelles 1996, Porembski et al 1998, Meirelles et al 1999, Gröger 2000, Safford & Martinelli 2000, and Ribeiro et al 2007, in this issue). The main families of vascular plants found here were also found elsewhere in "Chapada Diamantina" ) and even in south-east Brazil (e.g., Velloziaceae, Bromeliaceae, Orchidaceae, Cyperaceae, Asteraceae, Amaryllidaceae, Poaceae, Melastomataceae, Clusiaceae).…”

“…Similarly, genera such as Abildgaardia, Acianthera (Pleurothallis), Barbacenia, Clusia, Epidendrum, Hippeastrum, Lychnophora, Orthophytum, Polypodium, Tibouchina, Trilepis, Vellozia and Vriesea are commonly found in our study site and in other rock outcrops in Brazil (Oliveira et al 1975, Carauta & Oliveira 1982, Ibisch et al 1995, Meirelles 1996, França et al 1997, Porembski et al 1998, Waldemar 1998, Meirelles et al 1999, Safford & Martinelli 2000. Although some of these genera are broadly distributed, many species are endemic to "Chapada Diamantina" -including new species found that belong to the genera Barbacenia (Velloziaceae), Paepalanthus (Eriocaulaceae) and Jacquemontia (Convolvulaceae) -which confers a regional floristic peculiarity.…”

“…In South America, Ibisch et al (1995) referred to families such as Bromeliaceae, Cactaceae, Cyperaceae, Orchidaceae, Poaceae, and Velloziaceae as typical of local inselbergs, while Velloziaceae is typical also of African inselbergs (Sarthou & Villiers 1998, Michelangeli 2000. In Brazil, some of the earliest studies on plant communities in rock outcrops were those of SegadasVianna (1965), Oliveira et al (1975) and Carauta & Oliveira (1982).…”

Floristic diversity of two crystalline rocky outcrops in the Brazilian northeast semi-arid region

“…They are cited as being species well adapted to rocky outcrops, indicating a dystrophic substrate (Michelangeli 2000, Saridakis et al 2004. As a consequence of this nutrient limitation, combined with other edaphic and climatic factors, the plants show morphophysiological adaptations that result in high levels of endemism in these environments (Ibisch et al 1995, Porembski et al1996, Biedinger et al 2000, Seine et al 2000. Even thought the West face (leeward) of the rock outcrops was not evaluated, its composition appears to be very similar to the one at the East face (windward).…”

Structural analysis of the vegetation on a highland granitic rock outcrop in Southeast Brazil

“…Some species may grow roots into the substratum formed by the species that constitute these monocotyledonous mats (Porembski et al 1998). Depending on mat size, a shrub-mat complex can be formed, which represents an intermediate phase between rock surfaces and adjacent forest formations (Ibisch et al 1995). Another life form associated to monocotyledonous mats and their great water storage capacity is a group of ephemeral species known as "ephemeral and wet flush vegetation" (Barthlott et al 1993, Safford & Martinelli 2000.…”