The Venezuelan Andes montane forests (NT0175) is an ecoregion in the northern arm of the Andes in Venezuela. It contains montane and cloud forests, reaching up to the high-level Cordillera de Merida páramo high moor ecoregion. The forests are home to many endemic species of flora and fauna. Their lower levels are threatened by migrant farmers, who clear patches of forest to grow crops, then move on.
Geography
Location
The Venezuelan Andes montane forests ecoregion covers most of the Venezuelan states of Mérida and Trujillo, much the state of Táchira and the highlands of the states of Lara and Barinas. It includes a small area in Colombia. It covers the lower part of the Venezuelan extension of the Cordillera Occidental of the northern Andes. It has an area of .
To the southeast it adjoins the Llanos and the Apure–Villavicencio dry forests, and to the southwest adjoins the Cordillera Oriental montane forests. To the northwest it adjoins the Catatumbo moist forests and the Maracaibo dry forests. To the north it merges into Paraguana xeric scrub and La Costa xeric shrublands. It contains areas of Cordillera de Merida páramo on the higher ground.
Terrain
The Venezuelan Andes montane forests ecoregion contains the high altitude cloud forests of the Venezuelan Andean Cordillera, which reaches altitudes of .. This is a northeastern branch of the Andes that is separated from Colombia's Cordillera Oriental by the Táchira depression on the Venezuela–Colombia border. The ecoregion extends from the Táchira depression for about in a northeast direction to the Barquisimeto depression. The ecoregion also includes the forests of the isolated Tamá Massif, which lies between the Colombian Andes and the Táchira depression.
The mountains were formed during the Paleocene epoch and continued rising until the end of the Pliocene epoch. They are mainly composed of quartzite schist, gneiss and limestone, with isolated intrusions of granite and diabase. The soils are mostly inceptisols, but entisols are often found in slopes and eroded areas. The rivers that form near the summits create large valleys that form physiographical barriers between the ranges of the Cordillera. The largest, the Chama, crosses the northeast–southwest axis of the middle part of the Cordillera, dividing into the Cordillera de Mérida to the south and the Sierra de la Culata to the north. Other major rivers are the Santo Domingo, Boconó and Motatán.
Climate
The Köppen climate classification is "Cfb": warm temperate, fully humid, warm summer. From in elevation the average annual temperatures are . Temperatures are lower above this elevation. The northeastern trade winds strongly affect the climate. There is a dry season from December to April and a wet season from April to November when moisture is carried from the Intertropical Convergence Zone. Average annual rainfall is , but varies considerably from place to place. Along the southeastern slopes high rainfall starts above , while along the northwest slopes high rainfall starts at . Slopes in the interior valleys are dry, and often very dry.
Ecology
The Venezuelan Andes montane forests ecoregion is in the Neotropical realm, in the tropical and subtropical moist broadleaf forests biome. The ecoregion forms an ecological barrier between the Lake Maracaibo region and the Llanos. It has a great variety of plants, many endemic, and is seen as a plant refuge and dispersal center.
Flora
Vegetation includes evergreen transition forests between and and evergreen cloud forests higher up. The evergreen transition forests are dense, with two or three layers, with most trees of the families Lauraceae, Moraceae, Myrtaceae, Bignoniaceae, Euphorbiaceae and Araliaceae. From there are very dense cloud forests with two or three layers, many epiphytes and a rich understory. Common species are Retrophyllum rospigliosii, Prumnopitys montana, Podocarpus oleifolius, Alnus jorullensis, Oreopanax moritzii, Brunellia integrifolia, Hedyosmum glabratum, Weinmannia jahnii, Weinmannia microphylla, Tetrorchidium rubrivenium, Beilschemieda sulcata, Ruagea glabra and Ruagea pubescens.
The montane forests and páramos of Mérida have 155 endemic plant species, and contains 30% of the ecoregion's endemic flora. The forests and páramos of the isolated Tamá massif have another 82 endemic plant species. Common montane forest endemic plants are Podocarpus pedulifolius, Oreopanax veillonii, Psychotria aristeguiateae, Lagenanthus princeps, Delostoma integrifolium, as well as bromeliad, fern and orchid species.