Details

Autor(en) / Beteiligte

• Weigend, Maximilian

Titel

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

Ist Teil von

• The Botanical review, 2002-01, Vol.68 (1), p.38-54

Ort / Verlag

Bronx: New York Botanical Garden

Erscheinungsjahr

2002

Quelle

SpringerNature Journals

Beschreibungen/Notizen

• Some scientists have suggested that the Huancabamba Depression in northern Peru—i.e., the partial interruption of the Andean chain by the Río 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 Río Jubones system in Ecuador and the Río Chamaya system in Peru can be recognized from the available data. This zone seems to be home to numerous endemic species and species groups and has a high level of diversity (6–8 times as high as adjacent areas to the north and to the south in the groups studied). The species of this area show narrow endemicity and often strikingly aberrant morphological characters, compared with representatives of the same groups from other areas. The overlap between northern and southern groups in the area, the mosaic nature of its habitats (geology, geography, and climate), and a varied geological history (habitat fragmentation, secondary contact) seem to be the three most important factors contributing to these patterns of diversification. At least some phylogenetically old taxa appear to have survived in the Amotape-Huancabamba Zone. The region thus seems to be home to a high number of both neoendemics and paleoendemics.