Cauca Valley montane forests (NT0109) | |
---|---|
Ecology | |
Realm | Neotropical |
Biome | Tropical and subtropical moist broadleaf forests |
Bird species | >500 |
Mammal species | 120 |
Geography | |
Area | 32,412 km2 (12,514 sq mi) |
Countries | Colombia |
Coordinates | 4°50′20″N75°37′52″W / 4.839°N 75.631°W |
Climate type | Af: equatorial, fully humid |
The Cauca Valley montane forests (NT0109) is an ecoregion in western Colombia. It covers the sides of the Cauca Valley, which runs from south to north between the Central and Western Ranges (cordilleras) of the Colombian Andes. The ecoregion is home to very diverse fauna and flora, due in part to its varied elevations and climates, in part to its position near the isthmus of Panama, the route along which North American species invaded South America and then diversified as they moved to the upper parts of the Andes. Little of the original habitat remains at lower levels, but higher up there are sizeable blocks of forest, some of which are protected.
The Cauca Valley runs from south to north between the Cordillera Central and Cordillera Occidental of the Colombian Andes. It has an area of 3,211,585 hectares (7,936,000 acres). [1] The ecoregion covers both sides of the Cauca River valley, above the narrow strip of Cauca Valley dry forests that runs along the river. On the highest land of the cordilleras the ecoregion gives way to Northern Andean páramo. It transitions to the west into the Northwestern Andean montane forests ecoregion, and on the east into the Magdalena Valley montane forests. In the extreme north, where the river enters the Caribbean lowlands, the ecoregion transitions into the Magdalena–Urabá moist forests ecoregion. [2]
The Cordillera Central to the east of the Cauca Valley started to form in the late Paleozoic (541–252 Ma) on the western edge of a miogeocline, and was still low in the Cretaceous (145–66 Ma). The Cordillera Occidental to the west started to form at the end of the Mesozoic (252–66 Ma). The configuration of three Andean cordilleras in Colombia separated by two large valleys resulted from folding in the Miocene 23–5.3 million year ago (Ma). The mountains rose to the present elevations in the Pliocene (5.3–2.6 Ma) and Pleistocene (2.6 Ma to 11,700 years ago). [3]
The Cordillera Central has volcanoes and peaks with permanent snow rising to more than 5,000 metres (16,000 ft) above sea level. It has extremely fertile volcanic soil. The Cordillera Occidental rises to 4,000 metres (13,000 ft) above sea level.. It has laterite soils with some deposits of limestone on the foothills. [3] The Cauca Valley runs between these two ranges for about 600 kilometres (370 mi) from south to north. The foothills, starting at 1,000 metres (3,300 ft) above sea level, become increasingly steep at higher levels. They are cut by deep canyons formed by the many tributaries of the Cauca River. [3]
At a sample location at coordinates 4°45′N75°45′W / 4.75°N 75.75°W , the Köppen climate classification is Af: equatorial, fully humid. [4] Mean temperatures range from 19.5 °C (67.1 °F) in October to 20.3 °C (68.5 °F) in March. Total annual precipitation is about 2,300 millimetres (91 in). Monthly precipitation ranges from 116.1 millimetres (4.57 in) in July to 265 millimetres (10.4 in) in October. [4]
The ecoregion is in the neotropical realm, in the tropical and subtropical moist broadleaf forests biome. [1] The ecoregion is biologically diverse due in part to its varied altitudes and climates, and in part to exchange of species when the isthmus of Panama connected South and North America. It is a center of endemism for various taxa of flora and fauna. [3] It is part of the Northern Andean Montane Forests global ecoregion, which includes the Magdalena Valley montane forests, Venezuelan Andes montane forests, Northwestern Andean montane forests, Cauca Valley montane forests, Cordillera Oriental montane forests, Santa Marta montane forests and Eastern Cordillera Real montane forests terrestrial ecoregions. [5]
The ecoregion contains diverse formations of vegetation, including dry regions in the eastern foothills of the Cordillera Occidental with annual rainfall of 500 to 1,000 millimetres (20 to 39 in) and very humid forests in the middle and upper western slopes of the Cordillera Central with annual rainfall up to 3,000 millimetres (120 in). There is high diversity between species at different levels. North American species that invaded South America when the isthmus of Panama formed have differentiated in the mid- and high-elevation forests, including Alnus , Quercus , Talauma and Juglans species. The ecoregion is a center where shrubs and epiphytes in the Gesneriaceae, Orchidaceae, Rubiaceae, and Melastomataceae families have diversified and radiated. [3]
The montane forests extend from 1,000 to 3,000 metres (3,300 to 9,800 ft). They include palms of the genus Ceroxylon , including the Ceroxylon quindiuense . This may be the world's tallest palm, with heights that can exceed 60 metres (200 ft). Below 1,500 metres (4,900 ft) species of Fabaceae and Moraceae dominate. From 1,500 to 3,000 metres (4,900 to 9,800 ft) the majority of species are in the Lauraceae, Melastomataceae and Rubiaceae families. Above 3,000 metres (9,800 ft) the main families of flora are Ericaceae and Asteraceae. [3]
The Cauca Valley montane forests ecoregion is rich in species of fauna, including 200 of butterflies. [3] Butterflies such as the subtribe Pronophilina have closely related species at different elevations and on different slopes of the mountains. There are 120 mammal species. The spectacled bear (Tremarctos ornatus) and mountain tapir (Tapirus pinchaque) are of special concern. [3] Other endangered mammals include the black-headed spider monkey (Ateles fusciceps), Geoffroy's spider monkey (Ateles geoffroyi), Handley's slender opossum (Marmosops handleyi) and white-footed tamarin (Saguinus leucopus). [6]
There are over 500 bird species. This ecoregion contains a 19,000 square kilometres (7,300 sq mi) Endemic Bird Area as defined by BirdLife International. There are 12 restricted-range species, of which four are found only in the region. These include the Cauca guan (Penelope perspicax), restricted to a few remnants of humid forest at elevations from 1,200 to 2,200 metres (3,900 to 7,200 ft) on both sides of the valley. Other restricted-range or endangered bird species include the brown-banded antpitta (Grallaria milleri), moustached antpitta (Grallaria alleni), multicoloured tanager (Chlorochrysa nitidissima) and golden-plumed parakeet (Leptosittaca branickii). The golden-plumed parakeet and quetzals of genus Pharomachrus migrate regionally along the Andes slopes. [3] Endangered birds include the black-and-chestnut eagle (Spizaetus isidori), Cauca guan (Penelope perspicax), chestnut-bellied flowerpiercer (Diglossa gloriosissima), gold-ringed tanager (Bangsia aureocincta) and yellow-eared parrot (Ognorhynchus icterotis). [6]
92 species of frogs have been recorded, of which 60 are regionally endemic. Frog species vary by elevation, and different species are found at the same elevation on different slopes. [3] Endangered amphibians include the Angelito stubfoot toad ( Atelopus angelito ), Malvasa stubfoot toad ( Atelopus eusebianus ), painted stubfoot toad ( Atelopus pictiventris ), Atelopus quimbaya , Atelopus sernai , Sonson frog ( Atopophrynus syntomopus ), Johnson's horned treefrog ( Hemiphractus johnsoni ), Argelia Robber Frog ( Pristimantis bernali ), Serna's Robber Frog ( Pristimantis dorsopictus ), Rana picuda ( Pristimantis lemur ), Spotted robber frog ( Pristimantis maculosus ), Rana diminuta ( Pristimantis parectatus ), Los Patos robber frog ( Pristimantis scoloblepharus ) and Ruiz's robber frog ( Strabomantis ruizi ). [6]
Endangered reptiles include the Lepidoblepharis williamsi , Daniel's large scale lizard ( Ptychoglossus danieli ) and Colombian lightbulb lizard ( Riama columbiana ). [6]
The World Wide Fund for Nature (WWF) gives the region the status of "Critical/Endangered". At elevations from 1,000 to 2,000 metres (3,300 to 6,600 ft) most of the forest has been destroyed, with only isolated fragments remaining. The 519 hectares (1,280 acres) Yotoco Forest Reserve holds the largest such fragment. Higher up there are larger areas of forest. Protected areas include Farallones de Cali National Park, Tatamá National Natural Park and Los Nevados National Natural Park, and small regional reserves such as the Ucumarí Regional Park. The forests outside the national parks continue to be logged, and large birds and mammals are threatened by illegal hunting. [3] The Cinturon Andino Cluster Biosphere Reserve covers part of the ecoregion. [1]
The Cauca Valley dry forests is a tropical dry broadleaf forest ecoregion in Colombia.
The Marañón dry forests (NT0223) is an ecoregion in northern Peru. It covers the lower valley of the Marañón River and its tributaries along the eastern edge of the Andes. It has a dry climate due to rain shadow from mountains further east. The habitat has long been modified by farming, ranching and logging and is now threatened by construction of hydroelectric and irrigation dams.
The Patía Valley dry forests (NT0225) is an ecoregion in southwestern Colombia. It covers a dry valley surrounded by mountains. The original habitat has mostly been destroyed by human activity, although a few pockets remain.
The Magdalena Valley dry forests (NT0221) is an ecoregion in Colombia along the upper Magdalena River, a large river that runs from south to north between the two main cordilleras of the Andes. There are many endemic species, but much of the original habitat has been destroyed by agriculture and over-grazing, mainly by goats. The habitat is not protected by any national park, and is at risk of complete destruction.
The Northern Andean páramo (NT1006) is an ecoregion containing páramo vegetation above the treeline in the Andes of Colombia and Ecuador. In the past, when the climate was cooler, the treeline and the páramo units were lower and the units were connected. During the present warmer Holocene epoch the páramos have migrated uphill, shrinking and becoming isolated. They contain many rare or endangered species, some of them restricted to a narrow area of one mountain or mountain range. The ecoregion is relatively well preserved, but faces threats from over-grazing and farming.
The Santa Marta páramo (NT1007) is an ecoregion containing páramo vegetation above the treeline in the Sierra Nevada de Santa Marta mountain range on the Caribbean coast of Colombia. The isolated position of the range has allowed unique species to evolve. Some are related to those found in Central America and the Caribbean coastal areas, and some to species from the Andes. The habitat is relatively stable, but has been drastically changed from the original by long-term human activity.
The Cordillera Central páramo (NT1004) is an ecoregion containing páramo vegetation above the treeline in the Andes mountain range of northern Peru and southern Ecuador. Due to its isolation there are high levels of endemism. Despite many human settlements and some destruction of habitat by agriculture and mining, the ecoregion is relatively intact.
The Cordillera de Merida páramo (NT1004) is an ecoregion containing páramo vegetation above the treeline in the Andes mountain range of Venezuela. The isolated habitat has many endemic species. It is relatively stable and intact.
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.
The Tamá Massif is a group of mountains on the border between Colombia and Venezuela to the south of Lake Maracaibo. It contains evergreen rainforest and cloud forest at the lower levels, and páramos at the highest levels.
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.
The Napo moist forests (NT0142) is an ecoregion in the western Amazon rainforest of Colombia, Ecuador and Peru.
The Ucayali moist forests (NT0174) is an ecoregion in the western Amazon rainforest of Peru.
The Magdalena–Urabá moist forests (NT0137) is an ecoregion in the north of Colombia. The terrain is largely flat or undulating, but includes mountainous areas in the south. It contains moist forests and large wetlands that are important to resident and migratory birds. The ecoregion forms a bridge between the Pacific coast ecoregions of Colombia and Central America, and the ecoregions of the Andes and Amazon. It is surrounded by the more populated parts of Colombia and is threatened by farming, ranching, logging, oil exploitation and water pollution in the main rivers.
The Chocó–Darién moist forests (NT0115) is a largely forested, tropical ecoregion of northwestern South America and southern Central America. The ecoregion extends from the eastern Panamanian province of Darién and the indigenous region of Guna Yala to almost the entirety of Colombia's Pacific coast, including the departments of Cauca, Chocó, Nariño and Valle del Cauca.
The Northwestern Andean montane forests (NT0145) is an ecoregion on the Andes mountains in the west of Colombia and Ecuador. Both flora and fauna are highly diverse due to effect of ice ages when the warmer climate zones were separated and the cooler ones combined, and interglacial periods when the reverse occurred. Because the environment is hospitable to humans, the habitat has been drastically modified by farming and grazing since the Pre-Columbian era.
The Magdalena Valley montane forests (NT0136) is an ecoregion in the Andes mountains of central Colombia.
The Santa Marta montane forests (NT0159) is an ecoregion in the Sierra Nevada de Santa Marta, a massif on the Caribbean coast of northern Colombia. The ecoregion covers altitudes from near sea level up to around 3,300 metres (10,827 ft), where it gives way to Santa Marta páramo. The isolation of the massif and the range of elevations and climates has resulted in a wide variety of species including many endemics. The lower levels contained tropical rainforest, which has largely been cleared. Higher up, this gives way to cloud forest. Much of this has also been cleared for coffee plantations, pasture for sheep and cattle, and farming.
The Eastern Cordillera Real montane forests (NT0121) is an ecoregion in the eastern range of the Andes of southern Colombia, Ecuador and northern Peru. The ecoregion covers the eastern slopes of the Andes, and includes montane forest that rises from the Amazonian rain forest, with cloud forest and elfin forest at higher elevations. It is rich in species, including many endemics. It is threatened by logging and conversion for pasturage and subsistence agriculture.
The Western Ecuador Moist Forests (NT0178), also known as the Pacific Forest of Ecuador, is an ecoregion in the plains and western foothills of the Andes of southern Colombia and Ecuador. At one time this region contained dense forests with highly diverse flora and fauna, and many endemic species. Most of the original habitat has now been destroyed, and the ecoregion is one of the most threatened in the world.