ISSN:
1543-592X
Quelle:
Annual Reviews Electronic Back Volume Collection 1932-2001ff
Thema:
Biologie
Notizen:
Like South Africa's Greater Cape Floristic Region, the Southwest Australian Floristic Region (SWAFR) is species rich, with a Mediterranean climate and old, weathered, nutrient-deficient landscapes. This region has 7380 native vascular plants (species/subspecies): one third described since 1970, 49% endemic, and 2500 of conservation concern. Origins are complex. Molecular phylogenies suggest multiple dispersal events into, out of, and within the SWAFR throughout the Cretaceous and Cenozoic; in many phylogenetically unrelated clades; and from many directions. Either explosive speciation or steady cladogenesis occurred among some woody sclerophyll and herbaceous families from the mid-Tertiary in response to progressive aridity. Genomic coalescence was sometimes involved. Rainforest taxa went extinct by the Pleistocene. Old lineages nevertheless persist as one endemic order (Dasypogonales) and 6-11 endemic families. Such a rich flora on old landscapes that have been exposed to European land-use practices is highly threatened. Conservation programs must minimize soil removal and use local germplasm in restoration programs.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1146/annurev.ecolsys.35.112202.130201
