Rivasgodaya 7:69-98 (1993)
Vegetación de Bolivia: el Altiplano meridional
Gonzalo Navarro
SUMMARY
Navarro, G. Vegetation of Bolivia: the southern Altiplano. Ril'asgodaya 7: 69-98. 1993. A phytosociological study of Solivian Altiplano southward from 11'30' south latitude is prcscntcd. Thc total amount of phytosociological rclcvés (Braun-Bianquet's sampling method) is over 120, of which a number of 106 have been selected and are represented in the tables. The sampling is stratiried along the decreasing gradient of the annual rainfall on a north-south line running from La Paz lo Villazón and anotber east-west line from Uyuni to bolivian-chilean boundaries. Bcsidcs, a floristic catalogue and geobotanical pro!iles are also prcsentcd. Tbe southern Solivian Altiplano is a broad intra-Andean plateau between the west and the east mountain ranges. In Bolivia, the curren! area of dry Puna approxiroately coincides witb the pleistocenic Lake Minchín basin, wich probably has isolated plant populations lo the north and south of it. Tbe regional boundary line between tbe moisty and dry Puna goes a few kilometers lo the nortb of the Oruro city (approximately around 11'30' south latitude). The vegetation of the southern Puna is basically xerophytic in character, its xerophytic nature gradually increases from north to south and from east to west. Vast arcas are occupied by dry grass-steppc communities and bus hes, altcrnating witb balophytie and psammophytic vegetation. As a result of phytosociological analysis, the following vegetation units are recognized: l. Grass-steppeand bushycommunities (Calamagrostietea 1·icunari Rivas-Martínez & Tovar 1982) This class includes most of vegetation types of the high mountains and uplands of Central Andes from nortbcrn Perú to northern Chile and Argentina: thc wct and scmihumid north-central Puna and tbe dry, semiarid and arid soutbern Puna. The vegetal ion types are dominated by open tussock-grass shrubland in dryer areas (Porostreplrieta/io /epidoplryl/oe ord. nov.) and by meadowlike grass-scrub formation in moister Puna (Ca/amagrostietalia vicwrari Rivas-Martínez & Tovar 1982). In tbe order Parastreplrieta/ia lepidoplryllae, three alliances are recognized: • Parastrephion lepidfJphyllae al/. nov. Between 3300-4000 m altitude in Bolivia, it includcs azonal communities edaphically determined (exclusively distributed on deep clay or sandy soils). On the contrary, over 4000 m, they are climacic communities in the eastern andean mountain range, wich also colonized rocky slopcs and hillsides. Two associations are recognized: 1.1. Muhlenbergio fastigiotae-Parastrephiehm! lepidophyllae oss. nov. Tussock-grass shrubland growing on dccp clay soils of all uvial fans, pediments and carbonated lacustrine sediments surrouodiog the playas of salt-lakes and salt-marshes.