The Magdalena Valley dry forests (NT0221) is an

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

in Colombia along the upper

Magdalena River The Magdalena River ( es, Río Magdalena, ; less commonly ) is the main river of Colombia, flowing northward about through the western half of the country. It takes its name from the biblical figure Mary Magdalene. It is navigable through much of ...

, 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.

Location

The Magdalena Valley dry forests ecoregion is in the valley of the upper

, a river that flows north through the Andes to the

Caribbean The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean ...

. It has an area of . The Magdalena River is the largest in Colombia. The dry forests are almost entirely surrounded by the Magdalena Valley montane forests ecoregion. At its northern end the dry valley merges into the Magdalena–Urabá moist forests. It holds a small patch of the

Northern Andean páramo 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 c ...

ecoregion.

Terrain

The Magdalena River runs from the Central Massif between the Eastern and

Central Ranges Central Ranges (code CER) is an Australian bioregion, with an area of 101,640.44 square kilometres (39,244 sq mi) spreading across two states and one territory: South Australia, Western Australia, and the Northern Territory.Huila and Puracé volcanoes. The dry

Tatacoa Desert The Tatacoa Desert is the second largest arid zone in Colombia after the Guajira Peninsula. It occupies more than 330 square kilometers. This region is located north of Huila Department, 38 km from the city of Neiva in Colombia and from Nata ...

holds many vertebrate fossils dating from the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

era. The best soils are in areas with piedmont and alluvial valley landscapes, which cover 54.41% of the valley and are irrigated for agriculture. Areas of structural-erosional mountainous landscape cover 18.13% of the area and have no value for farming, so may be conserved as protected areas. Most soils are neither strongly acidic nor alkaline, with pH levels of 5.8–7.5. They have low or very low amounts of organic material, and low to medium levels of phosphorus. 69% of the soils are very susceptible to erosion and these mostly have low or very low natural fertility. Where these soils are not covered by vegetation they may be washed away during the rainy seasons.

Climate

The

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, nota ...

is "Am": equatorial, monsoonal. Annual rainfall in the Magdalena valley ranges from , distributed over two distinct rainy seasons. The rainy seasons last from April to July and from October to December. There is a water deficiency from April to September. In the

there is less than of rain annually. Mean annual temperature is . Temperatures rise to about in July and August.

Ecology

The Magdalena Valley dry forests ecoregion is in the

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

realm, in the

tropical and subtropical dry broadleaf forests The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive ...

biome.

Relation with other ecoregions

The Magdalena Valley dry forests ecoregion is part of the Tumbesian-Andean Valleys Dry Forests global ecoregion, which holds six terrestrial ecoregions:

Tumbes–Piura dry forests The Tumbes–Piura dry forests (NT0232) is an arid tropical ecoregion along the Pacific coasts of southern Ecuador and northern Peru. The ecoregion contains many endemic species of flora and birds adapted to the short wet season followed by a long ...

, Ecuadorian dry forests,

Patía Valley dry forests 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. Location The Patía V ...

, Magdalena Valley dry forests, Cauca Valley dry forests and

Marañón dry forests 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. T ...

. The fauna and flora of the global ecoregion have high levels of endemism. The climate has varied during the present

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...

period as glacial and inter-glacial cycles alternate. In glacial cycles the climate is drier and cooler by 2–8 °C (4–14 °F). Moist/wet forests retreat to refugia while the dry forests of the Magalena Valley extend to connect with other dry forests in Colombia and Venezuela, although the extremely humid Chocó region may remain a barrier between the northern dry forests and those of Ecuador and Peru. In inter-glacial cycles such as the present the warmer and more humid climate causes the moist forests to expand and dry forests to retreat into refugia. In this model the dry pocket and surrounding forests are considered to be the Alto Magdalena

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

refugium, a paleo-environment and a center of endemism. Many species of plants such as orchids, or birds and butterflies are endemic to the ecoregion.

Flora

Vegetation in the Tatacoa Desert is thorny, and includes

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Gree ...

species such as

Opuntia ''Opuntia'', commonly called prickly pear or pear cactus, is a genus of flowering plants in the cactus family Cactaceae. Prickly pears are also known as ''tuna'' (fruit), ''sabra'', '' nopal'' (paddle, plural ''nopales'') from the Nahuatl word ...

and

Melocactus ''Melocactus'' (melon cactus), also known as the Turk's cap cactus, is a genus of cactus with about 30–40 species. They are native to the Caribbean, western Mexico through Central America to northern South America, with some species along th ...

species, '' Armatocereus humilis'', ''

Stenocereus griseus ''Stenocereus griseus'', also known as the Mexican organ pipe, dagger cactus, pitaya, and pitayo de mayo, is a species of cactus. Description This tree-like cactus can grow up to 9 m tall, with stems up to 12 cm in diameter. Depending on t ...

'', ''

Acanthocereus tetragonus ''Acanthocereus tetragonus'', is a species of cactus that is native to Florida and the Lower Rio Grande Valley of Texas in the United States, Mexico, Central America, the Caribbean, and northern South America. The species is invasive in New Cale ...

'' and '' Pilosocereus colombianus''. The dry central pocket also includes umbrella-shaped woody species under including '' Pithecellobium bogotense'', ''

Capparis odoratissima ''Capparis'' is a flowering plant genus, comprising around 250 species in the family Capparaceae which is included in the Brassicaceae in the unrevised APG II system. These plants are shrubs or lianas and are collectively known as caper shrubs o ...

'', '' Bulnesia carrapo'', ''

Maclura tinctoria ''Maclura tinctoria'', known as old fustic and dyer's mulberry, is a medium to large tree of the Neotropics, from Mexico to Argentina. It produces a yellow dye called fustic primarily known for coloring khaki fabric for U.S. military apparel du ...

'', '' Fagara pterota'', '' Parkinsonia aculeta'', ''

Prosopis juliflora ''Prosopis juliflora'' ( es, bayahonda blanca, Cuji Venezuela, Trupillo Colombia, Aippia Wayuunaiki and long-thorn kiawe in Hawaii) is a shrub or small tree in the family Fabaceae, a kind of mesquite. It is native to Mexico, South America and th ...

'' and ''

Vachellia farnesiana ''Vachellia farnesiana'', also known as ''Acacia farnesiana'', and previously ''Mimosa farnesiana'', commonly known as sweet acacia, huisache, or needle bush, is a species of shrub or small tree in the legume family, Fabaceae. Its flowers are use ...

. Above the vegetation is replaced by montane cloud forest and

páramo Páramo () can refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrowe ...

. Endemic plant species include '' Steriphoma colombiana'', '' Amaria petiolata'' and '' Pithecellobium bogotense''. The endemic and highly endangered May flower (''

Cattleya trianae ''Cattleya trianae'' (Lind. & Rchb. fil), also known as ''Flor de Mayo'' ("May flower") or "Christmas orchid", is a plant of the family Orchidaceae. It grows as an epiphytic orchid, with succulent leaves, endemic to Colombia where it was nomin ...

''), the national flower of Colombia, grows in the transition forests between the dry and moist regions.

Fauna

Magdalena River Turtle (Podocnemis lewyana), Medellin

There are some endemic subspecies including the burrowing owl (''Athene cunicularia tolimae''),

crested bobwhite The crested bobwhite (''Colinus cristatus'') is a species of bird in the family Odontophoridae. It is found in northern South America, extending through Panama to just reach Costa Rica. It also occurs on Aruba and the Netherlands Antilles. Its ...

(''Colinus cristatus'' leucotis), velvet-fronted euphonia (''Euphonia concinna'') and eastern cottontail (''Sylvilagus floridanus purgatus''). Endangered mammals include the

white-footed tamarin The white-footed tamarin (''Saguinus leucopus'') is a tamarin species endemic to Colombia. It is a silvery brown colour with pale streaks and russet underparts, and is very similar in appearance to the cotton-top tamarin, from which it is separa ...

(''Saguinus leucopus'') and the mountain tapir (''Tapirus pinchaque''). Endangered reptiles include the

Magdalena River turtle The Magdalena River turtle or Rio Magdalena river turtle (''Podocnemis lewyana'') is a species of turtle in the family Podocnemididae,Crotalus durissus''. Other endemic or endangered species from the humid forests of the foothills include the

Colombian weasel The Colombian weasel (''Neogale felipei''), also known as Don Felipe's weasel, is a very rare species of weasel only known with certainty from the departments of Huila and Cauca in Colombia and nearby northern Ecuador (where it is only known fr ...

(''Mustela felipei''). Species that may be used as a source of income from supplying zoo nurseries, and thus less vulnerable, include red brocket (''Mazama americana''),

white-tailed deer The white-tailed deer (''Odocoileus virginianus''), also known as the whitetail or Virginia deer, is a medium-sized deer native to North America, Central America, and South America as far south as Peru and Bolivia. It has also been introduced t ...

(''Odocoileus virginianus''),

lowland paca The lowland paca (''Cuniculus paca''), also known as the spotted paca, is a large rodent found in tropical and sub-tropical America, from east-central Mexico to northern Argentina, and has been introduced to Cuba and Algeria. The animal is calle ...

(''Cuniculus paca''),

Central American agouti The Central American agouti (''Dasyprocta punctata'') is a species of agouti from the family Dasyproctidae. The main portion of its range is from Chiapas and the Yucatan Peninsula (southern Mexico), through Central America, to northwestern Ecua ...

(''Dasyprocta punctata''), eastern cottontail (''Sylvilagus floridanus''),

tapeti The common tapeti (''Sylvilagus brasiliensis''), also known as the Brazilian cottontail, forest cottontail, or (formerly) simply tapeti is a species of cottontail rabbit. It is small to medium-sized with a small, dark tail, short hind feet, and s ...

(''Sylvilagus brasiliensis''),

poison dart frog Poison dart frog (also known as dart-poison frog, poison frog or formerly known as poison arrow frog) is the common name of a group of frogs in the family Dendrobatidae which are native to tropical Central and South America. These species are ...

(''

Dendrobates ''Dendrobates'' is a genus of poison dart frogs native to Central and South America. It once contained numerous species, but most originally placed in this genus have been split off into other genera such as '' Adelphobates'', '' Ameerega'', '' A ...

'' species), toad (''

Bufo ''Bufo'' is a genus of true toads in the amphibian family Bufonidae. As traditionally defined, it was a wastebasket genus containing a large number of toads from much of the world, but following taxonomic reviews most of these have been moved t ...

'' species), harlequin toad (''

Atelopus ''Atelopus'' is a large genus of Bufonidae, commonly known as harlequin frogs or toads, from Central and South America, ranging as far north as Costa Rica and as far south as Bolivia. ''Atelopus'' species are small, generally brightly colored, ...

'' species),

tree frog A tree frog (or treefrog) is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia have given rise to treefrogs, although they are not closely rela ...

('' Hyla'' species), rain frog (''

Eleutherodactylus ''Eleutherodactylus'' is a genus of frogs in the family Eleutherodactylidae.Hedges, S. B., W. E. Duellman, and M. P. Heinicke . 2008. New World direct-developing frogs (Anura: Terrarana): molecular phylogeny, classification, biogeography, and c ...

'' species), foam nest frog (''

Leptodactylus ''Leptodactylus'' is a genus of leptodactylid frogs. It includes the species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is ...

'' species), spectacled caiman (''Caiman crocodilus''), green iguana (''Iguana iguana'') and

boa constrictor The boa constrictor (scientific name also ''Boa constrictor''), also called the red-tailed boa, is a species of large, non-venomous, heavy-bodied snake that is frequently kept and bred in captivity. The boa constrictor is a member of the family B ...

(''Boa constrictor''). 297 birds species have been reported, of which 35 were directly associated with the forest. Migratory birds of the

Thraupidae The tanagers (singular ) comprise the bird family Thraupidae, in the order Passeriformes. The family has a Neotropical distribution and is the second-largest family of birds. It represents about 4% of all avian species and 12% of the Neotropica ...

Parulidae The New World warblers or wood-warblers are a group of small, often colorful, passerine birds that make up the family Parulidae and are restricted to the New World. They are not closely related to Old World warblers or Australian warblers. Mos ...

and

Accipitridae The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...

families pass through the region. The western osprey (''Pandion haliaetus'') visits the north of the region in the winter. Parrots and hummingbirds migrate from higher regions. Long after it was thought to be extinct and the

yellow-eared parrot The yellow-eared parrot (''Ognorhynchus icterotis'') is an endangered parrot of the tropics in South America. It is found in the Andes of Colombia. This species was thought to be extinct up until April 1999, when a group of researchers that we ...

(''Ognorhynchus icterotis'') was rediscovered in the region. The

blue-billed curassow The blue-billed curassow (''Crax alberti'') is a species of bird in the family Cracidae, the chachalacas, guans, and curassows. It is endemic to Colombia. Taxonomy and systematics The blue-billed curassow is monotypic. However, it formerly ...

(''Crax alberti'') is no longer present. Endangered birds include the recurve-billed bushbird (''Clytoctantes alixii''). Altodelasrosas01

Status

The

World Wildlife Fund The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the W ...

gives the ecoregion the status of "Critical/Endangered". Much of the original habitat has been destroyed by agriculture and overgrazing, particularly by goats, leaving only a few forest patches along creeks and the Cabrera River in Tolima Department. Drilling and extraction of oil causes pollution around the Tatacoa desert. The population is poor, with limited education, often living in unhygienic conditions in shanty towns around large farms. On flat soils that can be ploughed by tractor the most common type of farming is irrigated rice production, rotated with sorghum and cattle. Other farmers grow rain-fed sorghum with cotton, corn or sheep and cattle, or grow rain-fed sesame plants and fruit trees. As of 2001, 69% of the area had been transformed by human activity. Of total, had been converted to agricultural use. There were no protected areas. Maps of the region from the early 21st century show about 31 irregular and fragmented remnants of dry forest, with an average size of . The ecoregion is considered to be at high risk of complete destruction.

References

Bibliography

* * * * * * * * {{Biodiversity of Colombia Neotropical dry broadleaf forests Ecoregions of Colombia Magdalena River