Northern Andean BioProvince
This BioProvince (as defined by Armen Takhtajan) comprising the northern or tropical Andes has been described as the richest and most diverse biodiversity hotspot on earth and has been referred to as a 'global epicentre of biodiversity.' The BioProvince includes the upland ‘Andean’ areas of Venezuela, Colombia, Ecuador, Peru, Bolivia, and the extreme northwestern part of Argentina. The Andes assumed most of their present form toward the end of the Tertiary period after an era of extensive volcanism. Since then the different cordilleras and great variety of slopes, peaks and isolated valleys have provided a multitude of habitats creating conditions for the evolution of vast numbers of plant and animal species. Some experts divide the tropical Andes into northern and southern zones, separated by the arid east-west valley that coincides roughly with the Ecuador-Peru border. It is called the Marañón Gap or Huancabamba Depression and serves as an east-west corridor between the Amazon and Pacific. South of the gap the mountains are older while the younger northern areas are still interspersed with numerous volcanoes. The climate is one of the most interesting in the World with radical changes throughout the region. In Ecuador it includes conditions suitable for tropical montane rainforests just a few miles away from snow-covered peaks. It also changes drastically from country to country. In Colombia it often rains, while in Ecuador it is usually dry. A crucial aspect of the high Andes is the extremely high diurnal changes in temperature. The vascular plant flora comprises an estimated 45,000-50,000 species - 15-17% of all the World's species. Some 20,000 of these are considered endemic and represents the riches concentration of endemic plants on the Planet.
The following accounts for this BioProvince have been written or will be written with particular reference to endemic and locally important species. Accounts available are displayed in green or yellow. Those displayed in red are either in the pipeline or awaiting expert contributions.
|Endemic Vascular Flora (Andes)|
Cattleya trianaei (Orchidaceae) an epiphytic orchid endemic to Colombia and confined to cloud forests in the Eastern Cordillera of the Northern Andes. It has been nominated the National Flower of Colombia. (Copyright © 2010 Peter Martin Rhind)