Cordillera Oriental montane forests

The Cordillera Oriental montane forests (NT0118) is an ecoregion in Venezuela and Colombia along the east slopes of the eastern cordillera of the Andes. The extensive region of submontane and montane forests includes distinctive flora and fauna in the north, center and southern sections. The ecoregion is home to numerous endemic species of fauna. Despite extensive changes due to logging, farming and ranching, large areas of the original habitat remain intact, and the ecoregion has rich biodiversity.

Geography

Location

The Cordillera Oriental montane forests ecoregion extends along eastern slopes of the Cordillera Oriental of the Colombian Andes, mostly in Colombia but in the northwest of Venezuela to the west of Lake Maracaibo. It has an area of .

At the northern end of the cordillera the ecoregion gives way to Guajira–Barranquilla xeric scrub. To the east, from north it south it adjoins the Maracaibo dry forests, Catatumbo moist forests, Venezuelan Andes montane forests, Apure–Villavicencio dry forests, Llanos, Caquetá moist forests and Napo moist forests. At its southern extreme it merges into Eastern Cordillera Real montane forests. To the west, from north to south, the ecoregion adjoins Sinú Valley dry forests and Magdalena Valley montane forests. At the upper levels the ecoregion gives way to Northern Andean páramo.

Terrain

The ecoregion covers the mid-level and high-level northern Andes, including foothills. There are three main sub-regions: the Serranía del Perijá in the north, somewhat isolated from the Cordillera Oriental and closer to the Sierra Nevada de Santa Marta, the northeastern slope of the Cordillera Oriental and the southeastern slope of the Cordillera Oriental. The southeastern slope extends southward from the west of the Tamá Massif past (and including) the Serranía de la Macarena. In the wider, northern section of this slope there are high, flat plains and páramos, and permanently snow covered peaks such as the Sierra Nevada del Cocuy. Further south it is narrower and lower, with peaks under .

Climate

The Köppen climate classification is "Cfb": warm temperate, fully humid, warm summer. At a sample location at coordinates mean monthly temperatures vary little throughout the year, ranging from to . Yearly total rainfall is about . Monthly rainfall varies from in January to in April, drops to in August and rises to in October.

Ecology

The ecoregion is in the Neotropical realm, in the tropical and subtropical moist broadleaf forests biome. It is in the Northern Andean Montane Forests global ecoregion, which also includes the Magdalena Valley montane forests, Venezuelan Andes montane forests, Northwestern Andean montane forests, Cauca Valley montane forests, Santa Marta montane forests and Eastern Cordillera Real montane forests. The Cordillera Oriental montane forests differ from other northern Andes montane forests due to the influence of the dry forests of the foothills and the Llanos grasslands.

The Serranía de Perijá in the north is in some ways more similar to the isolated Sierra Nevada de Santa Marta than to the eastern slope of the Cordillera Oriental. There are also significant differences in fauna of the northeastern and southeastern slopes, although flora are similar.

Flora

Up to about the vegetation is dense premontane or montane moist forest. Higher up this gives way to temperate oak forests and then elfin forests, before yielding to ericaceous scrub and páramo at the highest levels. There are pockets of premontane dry forest in areas with lower rainfall. Moist piedmont forest in the central part merges into the transition to the llanos grasslands. Moist piedmont forest in the southern part merges into the moist forest of the northwestern Amazon basin. The Serranía de la Macarena runs in a southeast direction from the southern part of the slope into lowland moist forest. It contains Andean, llanos and Amazonian species of flora. Plants of families such as Arecaceae and Meliaceae are very similar in the northeastern and southeastern slopes. 63 species of palms have been identified, of which 5 are endemic.

Fauna

The ecoregion has rich diversity of fauna. 878 species of birds have been identified with 18 endemic taxa, 169 species of frogs of which 32 are endemic Threatened species include the spectacled bear (Tremarctos ornatus). Other endangered mammals include Geoffroy's spider monkey (Ateles geoffroyi), red-crested tree-rat (Santamartamys rufodorsalis), mountain tapir (Tapirus pinchaque) and woodland Oldfield mouse (Thomasomys hylophilus). Endangered reptiles include Anolis ruizii and Colombian lightbulb lizard (Riama columbiana).