Chocó-Darién moist forests


The Chocó-Darién moist forests is an ecoregion in the west of Colombia and east of Panama. The region has extremely high rainfall, and the forests hold great biodiversity.
The northern and southern parts of the ecoregion have been considerably modified for ranching and farming, and there are threats from logging for paper pulp, uncontrolled gold mining, coca growing and industrialisation, but the central part of the ecoregion is relatively intact.

Geography

Location

The Chocó-Darién moist forests extend along most of the Pacific coast of Colombia and extend north into Panama along the Caribbean coast.
They are bounded to the east by the Andes, which separate them from the Amazon and Orinoco ecoregions.
They have an area of.
In Colombia the ecoregion is in the Chocó, Cauca, Valle del Cauca and Nariño departments. In Panama it is in the Darién and Guna Yala provinces.
The northern section merges into Isthmian-Atlantic moist forests to the west in the Isthmus of Panama, and contains patches of Eastern Panamanian montane forests.
Along the Caribbean coast there is a stretch of Amazon-Orinoco-Southern Caribbean mangroves.
To the east it adjoins the Magdalena-Urabá moist forests near the Caribbean coast, and then adjoins the Northwestern Andean montane forests ecoregion along the Andes to the east.
On the Pacific coast there are stretches of South American Pacific mangroves.
In the southeast an arm of the Patía Valley dry forests reaches down to the ecoregion.
In the extreme south the ecoregion merges into the Western Ecuador moist forests ecoregion.

Terrain

The ecoregion is between the Pacific Ocean and the Western Ranges of the Andes, with elevations from sea level to about.
It includes the western slopes of the Andes and the Cerro Torrá, Serranía del Darién, Sierra Llorona de San Blas and Serranía del Baudó massifs.
Terrain includes recently formed alluvial plains, hills formed in the Tertiary and Pleistocene from dissection of sediments, and older Mesozoic era rocks in the mountains.
The soils are typically red clay laterite, leached of most nutrients by the heavy rain.
Younger and more fertile soils are found along the Andes and in the main river floodplains.
Subregions include the hilly region of Darién and Urabá in the north; the Pacific coastal zone with elevations up to about ; the central strip; the hills of the El Carmen de Atrato and San José del Palmar municipalities; and the rainforest along the western Andes up to an elevation of about.
The ecoregion contains the basin of the Atrato River in the north, and further south the basins of the Baudó, San Juan, San Juan de Micay and Patía rivers.
The heavy rainfall gives these rivers great power, cutting deep gorges through the mountains with dramatic falls and rapids in the upper reaches.
Lower down the rivers broaden out and meander through the plains.

Climate

Annual temperatures average, ranging from a minimum of to a maximum of.
Annual rainfall is from. The central region receives the most rain, in some areas as high as, while the north and south are comparatively drier, and in some parts have short dry seasons in January–March.
At a sample location at coordinates the Köppen climate classification is "Af": equatorial; fully humid.
Mean temperatures range from in October–November to in April.
Annual rainfall is about.
Monthly rainfall ranges from in March to in October.

Ecology

The ecoregion is in the neotropical realm, in the tropical and subtropical moist broadleaf forests biome.
The rainforests are some of the richest in the world.
The ecoregion is part of the Tumbes-Chocó-Magdalena biodiversity hotspot.

Flora

There are at least 8,000 vascular plant species in the ecoregion, perhaps over 10,000, of which almost 20% are found nowhere else.
The mix of flora depends on elevation, water levels and the influence of the sea.
Many species are locally endemic, found only in small regions, so there is considerable diversity from one area to another.
There are no endemic families, but several endemic genera. Some genera, such as Trianaeopiper and Cremosperma, have many species.
Generally the lowland rain forests in the north hold trees associated with cow tree, with groves of bongo, wild cashew, Panama rubber, snakewood or bastard breadnut, Bombacopsis species, kapok tree and tonka bean.
There are large emergent trees that rise above the canopy.
The understory is rich is Mabea occidentalis and Clidemia, Conostegia and Miconia species.
Periodically flooded areas are often rich in cativo.
The southern part the rain forest has two strata of trees, and large emergent trees, with flourishing lianas and epiphytes.
The central zone has rain forests at higher altitudes and wet or very wet forests lower down.
Vegetation includes formations that would otherwise be found only in cloud forests, with thick moss and other types of non-vascular epiphytes on the tree trunks and branches, and with diverse species of woody hemiepiphyte lianas of the Ericaceae, Marcgraviaceae and Melastomataceae families.
There are many slender trees.
In the north and south near the coast, where there is a dry season, there are greater numbers of deciduous plants.
Above an elevation of common species include Inga species, cariseco, Brosimum species, Sorocea species, Jacaranda hesperia, Pourouma bicolor, Guatteria ferruginea, Cecropia species, Elaegia utilis and Brunellia species.

Fauna

There is high diversity of fauna in the Chocó-Darién moist forests ecoregion, and many endemic species.
The extremely high rainfall makes it difficult for many vertebrates to travel, forming gap in the distribution of several primates and other mammals.
Vulnerable or endangered mammal species include Geoffroy's tamarin, giant anteater, cougar, ocelot and jaguar.
Other endangered mammals include black-headed spider monkey, Geoffroy's spider monkey, Gorgas's rice rat and Baird's tapir.
577 species of birds have been recorded.
The most diverse family is tyrant flycatcher with 28 genera and 60 species.
The ecoregion is a center of bird endemism, with at least 60 species with restricted ranges.
These include the Choco tinamou, Baudó oropendola, viridian dacnis, crested ant tanager '', Lita woodpecker and plumbeous forest falcon.
Other rare birds include the harpy eagle, black-and-white hawk-eagle, and perhaps the speckled antshrike, although this last may no longer be present in Colombia.
Endangered birds also include great green macaw, rufous-brown solitaire, banded ground cuckoo, Baudo guan and Baudó oropendola.
There are records of 97 reptile species, including 35 from the family Colubridae and 26 from the family Iguanidae.
Endangered reptiles include Dunn's spinytail lizard and Boulenger's least gecko.
There are at least 127 amphibian species.
Endangered amphibians include the elegant stubfoot toad, El Tambo stubfoot toad, Lynch's stubfoot toad, Costa Rican variable harlequin toad, horned marsupial frog, lemur leaf frog, Lehmann's poison frog, golden poison frog and Myers' Surinam toad.

Status

The World Wide Fund for Nature gives the region the status of "Relatively Stable/Intact".
The northern parts in Colombia have mostly been replaced by banana plantations and cattle ranches.
The southern areas have been partly replaced by oil palm plantations, and are being deforested for paper pulp.
Most of the intact forest is in the central area.
However, the remaining blocks of habitat in 1995 were large, intact and well-connected.
There is high potential for research and ecotourism.
Some areas of secondary forest may be almost 500 years old, suitable for research into tropical forest regeneration.
As of 1995 10% to 20% of the original habitat had been destroyed, with one source at the time claiming 3.5% was being altered each year.
The Chocó forests supply half of Colombia's wood, and the main threat comes from deforestation and resultant erosion.
As of 1990 about was being deforested annually.
The Inter-American Highway in the Darien region is causing degradation of the habitat.
Industrial development is a threat.
The naval base at the entry to Málaga Bay may disrupt humpback whale reproduction.
Other threats come from plantations of African oil palm, gold mining and coca growing.
About 30% of the of the ecoregion in Panama is protected to some extent.
The Darién National Park is also a UNESCO World Heritage Site.
Other areas with some protection in Panama include the Kuna-Yala indigenous reserve and the Embera Wounan reserve.
Other parts of the ecoregion in Panama have been set aside as mining reserves or are used for agriculture.
In Colombia, as of 1997 about was protected by widely separated national parks, covering 2.5% of the ecoregion and 1% of the original habitat.
These include the Los Katíos National Park, which borders the Darien National Park of Panama, the Ensenada de Utria National Park, with land and marine sectors, the Sanquianga National Natural Park and the Gorgona Island National Park.
Parts of the ecoregion are also protected by the lower parts of the Farallones de Cali National Park and Munchique National Natural Park. Another large park in the area is Paramillo National Park.