Biogeographic patterns of southern South America: multivariate analyses based on plant and animal distributions

DONATO, MARIANO; POSADAS, PAULA; ORTIZ JAUREGUIZAR, EDGARDO; KATINAS,L.; SANCHO,G.; GROSSI,M.; CRISCI,J.V.

San Carlos de Bariloche

Congreso; VI Southern Connection Congress; 2010

The purpose of this study is to investigate similarity patterns of the biogeographic districts of Cabrera & Willink?s biogeographic schemes (1973, OEA Monographs n°13) of southern South America.Cluster (CA) and Non-metric multidimensional scaling (NMDS) were applied to analyze the regional diversity patterns. The 11 districts belonging to the Patagonian and Subantarctic biogeographic provinces occurring in southern South America were considered as units. Similarity was established based on Asteraceae (147 spp.), Curculionidae (315 spp.) and Chironomidae (155 spp.).The results obtained by CA and NMDS are similar. CA shows the following similarity associations: ((Magellanic Moorland, Islas Malvinas) (((Fuegian, Magellanic Forest) (Maule Valdivian Forest)) (Subandean (((Occidental Central) San Jorge Gulf) Payunia)))), cophenetic coefficient value= 0.8981. The phenogram exhibits similarity indexes ranging from 0.31169 in the highest association (Occidental and Central Patagonian districts) to 0.027778 in the lower asssociation (Magellanic Moorland, Islas Malvinas). The associations resulting from our analysis do not reconstruct the major biogeographic provinces to which the districts belong to. Remarkably, the Fuegian district is associated to Subantarctic districts instead of the Patagonian ones.