Phytogeographic characterization of the temperate coast of Pacific South America

Abstract

The benthic algal flora of Pacific South America (380 spp) includes endemic (32 · 3 %), subantarctic (34 · 4 %), tropical (3 · 4 %), widely distributed (22 · 8 %) and antitropical species (7 · 1 %). In general, the region (4–55°S) is characterized by high endemism and unequal contributions of tropical and subantarctic elements. Floristic exchange is small across the northern rim of the Perú Current since the contribution of Central American Pacific species to temperate South America is limited in both number of species and latitudinal range. Floristic exchange between South America and nearby off shore islands (e.g. Juan Fernández or Galápagos) has also been limited, as indicated by the small number of common elements. The partial blockade to species migration and colonization apparently explains the peculiar latitudinal species diversity gradient found along Pacific South America, where the number of species decreases towards the Equator. It also partially explains low species richness reported ...