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The Tropical Dry Forest in Colombia

Distribution and conservation status

Camila PizanoUniversidad Icesi Roy González-M.Instituto Alexander von Humboldt
Universidad del Rosario
René LópezUniversidad Distrital Francisco José de Caldas Rubén Darío JuradoAsociación GAICA Hermes CuadrosUniversidad del Atlántico Alejandro Castaño-NaranjoInstituto para la Investigación y la Preservación del Patrimonio Cultural y Natural del Valle del Cauca Alicia RojasCorporación Autónoma para la Defensa de la Meseta de Bucaramanga Karen PérezFundación Orinoquia Biodiversa Hernando Vergara-VarelaUniversidad del Cauca Álvaro IdárragaUniversidad de Antioquia Paola IsaacsInstituto Alexander von Humboldt Hernando GarcíaInstituto Alexander von Humboldt

The tropical dry forest is in a critical state of fragmentation and deterioration in Colombia. Most areas are under anthropic pressures such as cattle raising, human-built infrastructure, and agriculture.

The tropical dry forest (TDF) is found in the lowlands (0-1000 meters above sea level) and has a strong rainfall

seasonality with at least three months of drought (<100 mm of precipitation per year). This ecosystem shelters a unique diversity of plants, animals, and microorganisms that have adapted to its extreme conditions. TDFs contain around 2,600 species of plants1, at least 230 bird species2 and 60 different mammals, 83, 33, and 3 of them being species exclusively from this ecosystem, respectively3. Additionally, TDFs offer fundamental ecosystem services such as water regulation, soil retention, and carbon capture4,5

Since the TDF is found in relatively fertile soils and specific climatic conditions, humans have settled in the same areas. The TDF is therefore considered one of the most threatened ecosystems in the Neotropics6, to such extent that the Ministry of the Environment and Sustainable Development declared the TDF as a strategic ecosystem for biodiversity conservation.

Until now, the impossibility of having a detailed map of TDFs had impeded their integrated management. So it was necessary to quantify their distribution and determine which are the anthropic pressures that affect these forests. The current situation of TDFs reflects a severe fragmentation that implies a scant amount of forest remnants, possibly limiting the supply of ecosystem services.

Considering that the TDF is present in a very low percentage (6.4%) of the areas of the National System of Protected Areas7(SINAP for its initials in Spanish), and that of the original 9,000,000 ha it covered only 8% remains, it is imperative to establish integrated strategies for its management7. These strategies should consider priority areas for conservation, ecological restoration by enriching degraded areas (shrubs and secondary forests), and fragment connectivity in productive landscapes8,9. In this sense, the following strategies should take action immediately: (a) position a research and monitoring agenda for more focused restoration efforts; (b) revise those official maps that report fragments smaller than 25 ha; (c) increase representativeness in the SINAP based upon original coverage and not only existing remnants; (d) include TDF areas in regional efforts of protection and land-use planning; and (e) connect the efforts of Nature Reserves of the Civil Society with complementary strategies10,11.

In order to put the recommended suggestions into action, a collective effort that includes the government, environmental entities, academia, and the private sector should be guaranteed. This would unfold in a more detailed study of the ecosystem and actions directed towards the conservation of these forests.

Verification points of succession stages and the five main anthropic pressures on TDF for each region.

TDF
Verification points

653 TDF remnants were verified in the six regions where this ecosystem is distributed

CARIBBEAN REGION

AVERAGE SIZE OF TDF FRAGMENTS

394,3 ha


INFRAESTRUCTURE CATTLE RAISING
AGRICULTURAL
CROPS
INTENSIVE LOGGING
MINING

Average size of TDF area in different succession stages


Most mature dry forests are found in the Caribbean, the Llanos, and the Northern Andes region.

NORTH ANDEAN REGION

AVERAGE SIZE OF TDF FRAGMENTS

184,7 ha


INFRAESTRUCTURE AGRICULTURAL
CROPS

EROSION MINING
CATTLE RAISING

Average size of TDF area in different succession stages


The TDF is critically fragmented: in four of its six regions the average size of the areas is not greater than 100 ha.

LLANOS REGION

AVERAGE SIZE OF TDF FRAGMENTS

77,7 ha


INFRAESTRUCTURE CATTLE RAISING
FIRES EROSION
PLANTACIONES AGRÍCOLAS
Average size of TDF area in different succession stages

MAGDALENA RIVER VALLEY REGION

AVERAGE SIZE OF TDF FRAGMENTS

26,8 ha


CATTLE RAISING INFRAESTRUCTURE
AGRICULTURAL
CROPS
MINING FIRES


Average size of TDF area in different succession stages

CAUCA VALLEY REGION

AVERAGE SIZE OF TDF FRAGMENTS

31,2 ha


CATTLE RAISING INFRAESTRUCTURE AGRICULTURAL
CROPS

FIRES ECOTOURISM

Average size of TDF area in different succession stages


The smallest TDF fragments, and thus most vulnerable, are found in the geographical valley of the Cauca River and the canyon of the Patía.

PATÍA VALLEY REGION

AVERAGE SIZE OF TDF FRAGMENTS

24,8ha


AGRICULTURAL
CROPS
CATTLE RAISING
EROSION FIRES INFRAESTRUCTURE


Average size of TDF area in different succession stages

SOME SPECIES FOUND IN DIFFERENT TDF SUCCESSION STAGES

Shrubs

32,5% of actual TDF are shrubs

Pumpwood

Cecropia angustifolia > see species sheet 15m

Medium sized tree with thin stems

Calabash Tree

Crescentia cujete > see species sheet 7m

It's dry fruit is widely used as recipient

Secondary forest

33,4% of actual TDF are secondary forest

Calabash Tree

Crescentia cujete > see species sheet 7m

It's dry fruit is widely used as recipient

Sandbox Tree

Hura crepitans > see species sheet 60m

Tree with timbering value

Rosy Trumpet Tree

Tabebuia rosea > see species sheet 20m

Fine wood tree with elongated crown with shiny foliage

Glassywood

Astronium graveolens > see species sheet 40m

Medium sized trees with thin stems

Primary forest

23,4% of actual TDF are primary forest

Glassywood

Astronium graveolens > see species sheet 40m

Medium sized trees with thin stems

Pinguin

Bromelia pinguïn > see species sheet 1m

Leafs in rosette

Pink flowers

Carreto

Aspidosperma polyneuron > see species sheet 40m

The wood is very hard, resistant and with showy yellowish streaks

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TOPICS

TROPICAL DRY FOREST ENDEMIC SPECIES TRANSFORMATION FRAGMENTATION