Andes: Sajama National Park (W-Bolivia)

The Bolivian Altiplano is a large semiarid landscape between 3800 and 4300 m elevation, surrounded by mountain ranges > 5000 m a.s.l. Precipitation of 250-350 mm per year is restricted to the austral summer (December-March). It is unresolved whether much of that terrain originally was open Polylepis (Rosaceae) woodland. A treeline in the classical sense does not exist, but patches of trees can be found up to 4800 m. The restriction of Polylepis tarapacana woodlands to steep rocky slopes led to a downslope extension of the alpine zone (similar to Kilimanjaro). It is unquestioned that the current vegetation reflects the millennial impact of fire management and camelid grazers such as llamas, alpacas and vicuñas. The sparse herbaceous flora consists of tiny annuals and tap-rooted perennials as shown here.