La flora altoandina de los sectores este y oeste del Parque Nacional Nahuel Huapi, Argentina.

FERREYRA, M.; CLAYTON, S.; EZCURRA, C.

DARWINIANA

Instituto Darwinion

Año: 1998 vol. 36 p. 65 - 79

0011-6793

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;} p.MsoPlainText, li.MsoPlainText, div.MsoPlainText {margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Courier New"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->     The floristic composition and species richness of the western     (moister) and eastern (dryer) areas of the High Andean region of     Nahuel Huapi National Park (Argentina) were compared. Species lists     were compiled for the two sectors from collections in the alpine     area of 20 mountains of the Park (10 from each sector) from 1993 to     1997. A total of 232 species, 111 genera and 48 families were     recorded. Asteraceae (with 70 species), Poaceae (17), Apiaceae (12),     Fabaceae (11) and Scrophulariaceae (11) are the predominant families     in the area, and /Senecio /(with 22 species),/ Nassauvia /(12),     /Acaena /(7), and/ Perezia/ (7) are the best represented genera.     There are six endemic species in this protected area. The most     frequent life forms are perennial herbs and subshrubs, followed by     shrubs, and annual species are nearly inexistent. Species richness     was found to increase in relation to the precipitation decrease from     west to east: 149 species were found in the moister western sector     and 220 in the dryer eastern sector. Some families and genera are     more represented or appear exclusively in one of the two sectors. We     discuss current ecological and past historical factors that could     explain this variation in species diversity and composition.   Key words: Southern Andes, High Andean flora, Species richness, Precipitation gradient.