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This moist forest ecoregion
is considered one of
the most species rich
lowland areas in the
world, with exceptional
abundance and endemism
over a broad range of taxons
that include plants,
birds, amphibians and
butterflies. Its biological
distinctiveness is outstanding
in the world, with
great biological, ecological
and evolutionary biodiversity.
In addition, this
ecoregion is culturally rich
in that numerous indigenous
communities with strong ties to its ecosystems still
persist here. |
The ecoregion of the wet forests of Chocó-Darién extends
from eastern Panama, in the provinces of Darién and Kuna-
Yala, along almost the entire Pacific Coast of Colombia, in
the departments of Chocó, Cauca, Valle del Cauca, and
Nariño. Thus running between latitudes 9º to 1º15’ north,
then down to 2° S and longitudes 79º to 76º15’ west. This
ecoregion encompasses a strip of land from sea level to an
elevation of approximately 1,000 meters. It lies between the
Pacific Ocean and the western range of the Andes; from
west of the mouth of the Atrato River, in Panama to the
Patia River, in Colombia. |
Average annual temperature is generally 23.6ºC, with a
maximum average of 30ºC and a minimum of 18.6ºC. The
biogeographic Chocó is probably the only ecoregion of this
size with the precipitation, from 4,000 to more than 9,000
mm per year. It is also one of the few places in the Neotropics
with pluvial rainforest.
Precipitation in the ecoregion
varies - with less in the northern zone, higher amounts in the
central region and less again in the south. Some sectors may
receive more than 13,000 mm of precipitation per year.
There are three principal geomorphologic types in the ecoregion:
alluvial plains of recent origin, low mountains
formed by the relatively recent dissection of sediments from
the tertiary and pleistocene periods, and the complexes in
mountain areas consisting of mesozoic rocks. The high
precipitation and the topography mean that the ecoregion
includes a complex of great hydrographic basins, the most
important being those of the Atrato, Baudó and San Juan
Rivers and the Micay and Patía Rivers in the south. The
force of the water in many of these rivers form deep gorges
cutting through the mountains, creating spectacular rapids
and waterfalls in the mountains, along the upper courses. At
lower elevations, large rivers become very wide and with
many meanders. Given the high precipitation in the region. |
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dominated by the deciduous "cuipo" or "ceiba bonga" tree
(Cavanillesia platanifolia), the "aspavé" or wild cashew
(Anacardium excelsum), the "táparo" (Catilla elastica), the
rubber tree (Castilla elastica), Brosimum guianense, Bombacopsis
spp., Ceiba pentandra, Dipteryx panamensis, and
others. In the undergrowth Mabea occidentalis, Clidemia
spp., Conostegia spp. and Miconia spp. are abundant. In
zones that are occasionally flooded, the "cativo" (Prioria
copaifera) flourishes as well. In the southern part of the
ecoregion, these rainforests have multiple strata, with two
layers of trees, lianas and epiphytes with vigorous growth
rates. The number of deciduous plants increases in the north
and south, where there is a dry season, particularly near the
coast. The forests at higher altitudes, starting at 600 m, have
communities with the following species: "guamos" (Inga
sp.), Billia columbiana, Brosimum sp., Sorocea sp., Jacaranda
hesperia, Pourouma chocoana, Guatteria ferruginea,
Cecropia sp., Elaegia utilis and Brunellia sp.
Chocó-Darién corresponds to one of the largest active centers
of speciation and endemism in the world. The flora of
Chocó is estimated at a minimum of 8,000 species of vascular
plants and possibly more than 10,000 with nearly 20%
strictly endemic. Although there are no endemic families,
there are endemic genera, some of which have undergone a |
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| considerable amount of speciation, including Trianaeopiper
and Cremosperma. Local endemism is characteristic of the
region, indicating that many species have very restricted
ranges of distribution and giving rise to an extraordinary N
(beta) - diversity. |
In the central zone of the ecoregion, we find a mosaic of
rainforests at higher elevations and very wet or wet forests
in the lower coastal ranges. These rainforests of the Chocó
have distinct plant life that is usually confined to cloud forests
at medium elevations (about 1,000 meters ASL) yet this
habitat is not. It includes characteristics such as thick moss
cover and other non-vascular epiphytes on trunks and
branches and the prevalence of woody hemiepiphytic lianas
belonging to the families Ericaceae, Marcgraviaceae and Melastomataceae, all of which have centers of diversity in
the region. In addition, there are high densities of slender
and average and not very thick trees and low biomass
(Faber-Langendoen et al. 1991). In the areas to the north
and south of the ecoregion a different type of rainforest in
terms of physiognomy and plant life occurs. These forests
have large emergent trees and a high biomass. |
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