Observations on the Biogeography of the Amotape-Huancabamba Zone in Northern Peru

Abstract

ABSTRACT Some scientists have suggested that the Huancabamba Depression in northern Peru—i.e., the partial interruption of the Andean chain by the Rio Chamaya drainage system—represents a major biogeographical barrier to montane taxa. Others have suggested that the Amotape-Huancabamba Zone in the Andes of northern Peru and the extreme south of Ecuador is an area of particular biological diversity and possibly a phytogeographical zone in its own right. The phytogeography of this area is investigated here with data mainly from the Loasaceae, supplemented by data on other plant and animal groups and by some new data from Passiflora L. (Passifloraceae) and Ribes L. (Grossulariaceae). The Huancabamba Depression itself does not seem to have been a major dispersal barrier for these groups. However, a phytogeographical zone—the Amotape-Huancabamba Zone—between the Rio Jubones system in Ecuador and the Rio Chamaya system in Peru can be recognized from the available data. This zone seems to be home to numerous ende...