Cordillera de Merida páramo

Köppen climate zones of the Cordillera de Merida

The Cordillera de Merida páramo is to the south of the Lake Maracaibo in the Cordillera de Mérida massif of northeastern Venezuela. It has an area of 284,898 hectares (704,000 acres).[1] It is surrounded by the Venezuelan Andes montane forests ecoregion.[2]

Páramos in the southwest of the Cordillera de Merida include Batalló at 3,913 metres (12,838 ft) above sea level and Nariño at 3,517 metres (11,539 ft). The highest point in the central section is the Piedras Blancas peak at 4,729 metres (15,515 ft), surrounded by extensive páramos, glaciers and lakes. From the Piedras Blancas páramo the land descends to the Mucuchíes páramo at 4,077 metres (13,376 ft), then continues to gradually descend towards the northeast.[3]

The Köppen climate classification is "ETH": Alpine tundra, with no month with an average temperature in excess of 10 °C (50 °F).[4][5] Where the Northern Andean páramo is generally humid throughout the year with moisture delivered in the form of rain, clouds and fog as air masses are lifted up over the mountains, the Cordillera de Merida páramo is similar to the Costa Rican páramo and Santa Marta páramo, where the trade winds create a distinct dry season.[6] The dominant winds blow northwest from the Amazon region, with a rainy season from around March to November.[7]

The Andes began to rise in the Miocene epoch, but in the north did not reach their present height until the Pliocene during a period of strong volcanic activity between four and five million years ago. This was the period when land rose above the tree line and the protopáramo vegetation was formed with new species of the Poaceae, Cyperecear, Arteraceae, Ericaceae and other families. During the later parts of the Quaternary epoch a series of short, cold and dry glacial periods alternated with warmer and more humid interglacial periods. The páramo belts moved lower and joined together in the cold periods, and moved higher into unconnected enclaves when the temperatures rose.[9]

The result is a mix of species of tropical and boreal origin with the same genera found in most páramos, but with many endemic species in the individual páramos. The Cordillera de Mérida is the oldest part of the northern Andes, and has a large connected corridor of páramo. The range is probably where most of the páramo flora of tropical origin developed, then migrated south into Colombia during cold glacial periods.[9]

Horses in the Sierra La Culata National Park

The mountain forest extends up to about 3,000 metres (9,800 ft) in altitude, where the páramos begin, Above 4,000 metres (13,000 ft) the páramos are replaced by a periglacial zone with very little vegetation, mostly lichens, mosses and some dwarf plants.[10] No flora or fauna are found above around 4,850 metres (15,910 ft).[11] The ecoregion mostly consists of dry páramo habitat, with high-altitude tussock grass, stands of dwarf bamboo and open meadows There are also some marshes and bogs, although less than in the wet páramo.[1]

Redonda chiquinquirana, a butterfly whose females have limited ability to fly, is endemic to the ecoregion.[12] A study of Carabid beetles found diverse and numerous specimens, all endemic to the ecoregion although closely related to species in other ranges. Carbonellia ater is found between 2,900 and 4,300 metres (9,500 and 14,100 ft). The most important Carabid tribes in terms of numbers of species and of individuals belong to the genera Dyscolus and Bembidion.[13] Endangered amphibians include the Mucubaji stubfoot toad (Atelopus mucubajiensis) and Tamá harlequin frog (Atelopus tamaense).[14] Endangered mammals include Musso's fish-eating rat (Neusticomys mussoi).[14]