The high species richness and diverse ecological systems of the Colombian Amazon are the result of its geographical position and the synergy of geological, climatic, biogeographic, ecological and evolutionary processes that have occurred over time. Below are descriptions of the main biological groups:
The region is characterized by high forests (canopy greater than 25m), medium forest (canopy 10-25 m), low forest (<canopy 10m), alluvial forests, shrublands, grasslands, and high savannas.
The Colombian Amazon has 4,651 documented vascular plant species, grouped in 204 families belonging to the Magnoliophyta, Pteridophyta, Coniferophyta, Cycadophyta, Lycophyta, Gnetophyta and Sphenophyta biological divisions. The Magnoliophyta division is the largest, being represented by a total of 174 families and 4,387 species. The Pteridophyta division comes second with 22 families and 224 species.
At the family level, Rubiaceae has the largest number of genera (69). This is followed Euphorbiaceae (47), Fabaceae (46), Poaceae (37), Asteraceae (34), Melastomataceae (32), Bignoniaceae (29), Orchidaceae (28), Apocynaceae (26) and Caesalpiniaceae (25).
The genera with the most species are Psychotria (Rubiaceae), Miconia (Melastomataceae) and Inga (Mimosaceae) with a total of 92, 90 and 75 species, respectively.
Mammals: Didelphiomorphia, Phyllophaga, Cingulata, Vermilingua, Chiroptera, Primates, Carnivora, Cetacea, Sirenia, Perissodactyla, Artiodactyla, Rodentia and Lagomorpha orders are found in the region. Chiroptera is the order that presents a greater richness (103 species), followed by Rodentia (27 species), and lastly Sirenia, Perissodactyla and Lagomorpha orders with a single species recorded for each.
Most mammals found in the Colombian Amazon are characterized by having arboreal habits. They are respectively followed by terrestrial, climbing, aquatic and semiaquatic.
Reptiles: There are approximately 206 species of reptiles reported in the Colombian Amazon. Snakes (126 species), lizards (60 species) and turtles (13 species) are the most abundant. Most are carnivorous.
Snakes are represented by the Colubridae families with a total of 90 species. This is followed the Elapidae subfamily Micrurinae (12), Viperidae subfamily Crotalinae (10), Boidae (6), Leptotyphlopidae (5), Typhlopidae (2) and Aniliidae (1). With regard to lizards, 60 species belonging to 10 families are reported registered for Colombia. The turtles that have been registered belong to four families (Pelomedusidae, Chelidae, Kinosternidae and Testudinidae) and contain 13 species corresponding to the genus Podocnemis, Peltocephalus, Chelus, Phrynops, Platemysplatycephala, Rhinemys, Kinosternon and Geochelone. Crocodiles are represented by the genus Caiman and the C. Crocodylus, C. niger, C. palpebrous, and C. trigonatus species.
Birds: Birds present in the Colombian Amazon are estimated at 988 species in 18 orders, 58 families and 7 subfamilies. The orders which contain higher species richness are Passeriformes (589 species), Apodiformes (77), Piciformes (71) and Falconiformes (50). Orders less represented are Trogoniformes (10 species), Anseriformes (7) and Pelecaniformes (2). At the family level, Emberizidae, Tyrannidae and Formicariidae are distinguished due to their high richness, this being 142, 134 and 105 species respectively.
Amphibians: The amphibian fauna consists of about 140 species distributed among 131 frogs, 1 species of salamander, and 8 species of caecilians. Anuran families with highest species richness are Hylidae (51 species), Leptodactylidae (45) and Bufonidae (10); in contrast, are less represented are Centrolenidae (5 species), Pipidae (2) and Ranidae (1). With regard to the diversity of salamanders, only one species has been recorded: Bolitoglossa. Altamazonica. Furthermore, 8 species of caecilians of the genera Caecilia, Oscaecilia, Potomotyphlus, Siphonops, Microcaecilia and Typhlonectes have been reported.
Fish: The area of the Colombian Amazon contains more than 753 species of fish, which positions it as the richest region of these organisms in Colombia. This species richness is distributed in 14 orders and 47 families. More orders are represented in Characiformes (367 species), Siluriformes (228) and Perciformes (87). The orders with lower species richness are Batrachoidiformes (1 species), Synbranchiformes (1) and Lepidosireniformes (1). At the family level, Characidae, Cichlidae, Loricariidae and Pimelodidae show the highest amount of richness with a total of 208, 80, 56 and 40 species, respectively.
Ruiz S. L., Sánchez E., Tabares E., Prieto A., Arias J. C, Gómez R., Castellanos D., García P., Rodríguez
L. (eds). 2007. Diversidad biológica y cultural del sur de la Amazonia colombiana – Diagnóstico. Corpoamazonia, Instituto Humboldt, Instituto Sinchi, UAESPNN, Bogotá D. C. – Colombia. 636 p.
Jaramillo D., Rojas A., Ortíz N. 2011. Retos para un desarrollo sostenible: Transformaciones en la Amazonia colombiana. Fundación Alisos. Bogotá D.C. – Colombia. 126 p.