TAILIEUCHUNG - Biogeography of South West Asian bryophytes – with special emphasis on the tropical element

The recent bryophyte flora of South-West Asia is heterogeneous and consists of 6 floral elements [(Sub)cosmopolitan taxa, northern taxa, xerotherm-Pangaean taxa, circum-Tethyan taxa, tropical taxa, and endemics of various origins] that are derived from the different Pangaean ancestral floral stocks. | Turk J Bot 32 (2008) 433-446 © TÜBİTAK Biogeography of South-West Asian Bryophytes – With Special Emphasis on the Tropical Element Harald KÜRSCHNER Freie Universität, Institut für Biologie, Systematische Botanik und Pflanzengeographie, Altensteinstr. 6, D-14195 Berlin, GERMANY Received: Accepted: Abstract: The recent bryophyte flora of South-West Asia is heterogeneous and consists of 6 floral elements [(Sub)cosmopolitan taxa, northern taxa, xerotherm-Pangaean taxa, circum-Tethyan taxa, tropical taxa, and endemics of various origins] that are derived from the different Pangaean ancestral floral stocks. Analysis of the flora and vegetation indicates that there is a very strong tropical – and especially palaeotropical and Afromontane – influence in the bryophyte flora of the area. Altogether, more than 95 taxa, or nearly 10% of South-West Asia’s total known bryoflora, are of xero-tropical origin. They concentrate mainly in the escarpment mountains of the Arabian Peninsula and Socotra Island, and often are unique relicts of a former wider distributed Tertiary xero-tropical flora that today links South Arabia with East Africa and South-East Asia. Key Words: Chorology, circum-Tethyan, floral history, liverworts, mosses, xerotherm-Pangaean Introduction Floral (geno-) Elements Within the evolution of the bryophytes, one can distinguish 2 outstanding phases, which in connection with plate tectonic processes are of decisive significance for all biogeographical considerations. Bryophytes originated in the Lower Devonian c. 350 million years ago. Already at the end of the Permian period, the major groups of Marchantiophyta (the former Hepaticae) and Bryophyta (Musci) were evolved and are represented by today’s evolutionary lines (Frey, 1977; Oostendorp, 1987; Heinrichs et al., 2007). After this ‘macroevolution’ and the differentiation of the major groups in the Mesophyticum, no major evolution of new higher-ranked categories took place (Oostendorp,

• Nông nghiệp
• Circum Tethyan
• Floral history
• Xerotherm Pangaean
• Pangaean ancestral floral stocks
• Tropical taxa