Comparación entre dos ecosistemas tropoandinos: la puna chilena y el páramo ecuatoriano
Quintanilla Pérez, Víctor
Cita de ítem
Inform geogr Chile 30 (1983) pp. 25-45
This survey is a preliminary, comparative study of the phyto-ecologic features of two great types
of ecosystems of the Andes mountain range.
It deals with the Chilean 'puna" in northern Chile (volcanic region of the Pallachatas, lsluga,
Guallatire, and Colorado hills al1 of which are over 6.000 m above sea level) and the Ecuador
paramos (volcanic regions of Cotopaxi and Rumiiiahui in the west and the central range of the
Numerous samples were collected in the field according to the Canfield lineal method and
the Braun-Blanquet one. The data were used to establish the frequency percentage, prevalence,
covering, and importance index of shrubs and herbaceous species representative of vegetal
formations. These groups were found on the vegetal range floor of the "puna"and 'paramo"
(over 3.000 m above sea level). They proved to have a very similar composition in gender and
family but they are different at the level of species. There were only two plants. Stipa-ichu and
dense Azorella which presented a high index of common representativeness in both ecosystems.
This botanical variety is mainly due to the different ways that the definitive ecological factors
affect the development of herbaceous species. In the "pararno", there are some factors that help
the development of extensive shrub and herbaceous communities, such as, favourable exposition,
high atmopheric humidity, and high rainfall. Al1 of these help provide a high degree of cover
anda dense physiognomy. Meanwhile, in the "puna" there are some factors, such as the high
atmospheric dryness, low rain fall, and the existence o f unfertile soils which are appropriate for the
development of plants adapted to dryness, cold, and wind. They contribute to the formation of
open intermediate altitude shrubs and rangelands lower in altitude than in the 'paramo".
The comparative tables and the vegetal profiles show the predominance of herbaceous
species in the high mountain communities and the extense akitudinal distribution of these. Some
are living close to the lower limit of the eterna1 snows of the volcanoes.
Specific, morphological, and physiological functions of the plants would explain the great
ecologic adaptability of these species to exist in mountains over 5.000 m in altitude.