Cordillera La Costa montane forests

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Rancho Grande, Venezuela. (Photograph by David Olson)

Introduction

This region is located in elevational patches between middle and high elevations along the Venezuelan northern coastal range mountains (between 600 –2,675 meters (m) in the high summits), and supports extraordinarily diverse montane evergreen forests. Separated physically from the Andes by the Yaracuy depression, and from the forests of the Guyanan floristic province by the extensive plains of the Andes (llanos), these mountains are isolated from one another by much drier surroundings lowlands. Isolation and a great variety of physiographical scenarios, have created an extraordinary species richness and strong speciation processes that are manifested in a relative high level of plant and animal endemism.

Location and General Description

The Cordillera de la Costa montane forests are located in the northern coastal range of Venezuela. The ecoregion is composed of various enclaves that range from approximately 600 to 2,675 meters above sea level (m.a.s.l.). The Cordillera de la Costa, or Costa mountain range, is separated from the Andes by the Yaracuy depression, and from the southern forests of the Guyanan floristic province by the extensive Llanos. The montane forests are isolated from one another by xeric vegetation.

The Cordillera de Costa extends 720 kilometers (km) from east to west along the northern coast of Venezuela. The western section of the Cordillera lies in the state of Yaracuy, where the depression of the Yaracuy River forms a natural southwestward separation. Two main portions of the western Cordillera de la Costa are usually recognized, the Serranía del Litoral in the northern mountain range along the coastline of the Caribbean Sea, and the Serranía del Interior south of Valencia lake, and the valleys of Caracas. The most important mountains of the Serranía del Litoral are the Avila (2,200 m), La Silla de Caracas (2,650 m), and Pico Naiguatá (2,675 m, the highest peak of the entire cordillera) located northeast of Caracas. Pico Codazi (2,200 m), near Colonia Tovar, and mountains of Rancho Grande are located to the north of Maracay City. The Serranía del Interior includes Cerro Platillón (1,930 m), and the mountains of Guatopo (1,800 m). The eastern section of the Cordillera de la Costa, includes the mountainous areas east of Bergantín and those around Caripe, with a maximum elevation of 2,596 m at Cerro Turimiquire and the mountain range of the Paria Peninsula. This Peninsula has two high peaks with montane forests: Cerro Humo (1,350 m) and Cerro Patao (1,048 m).

The Cordillera de la Costa, formed during the Tertiary period, is older than the Andes. This mountain range started to be lifted by tectonic movement during the upper Cretaceous period, and attained its present configuration with an orientation from west to east. The Cordillera de la Costa consists mainly of schist and gneisses, underlain in some parts by granites; also limestones are present in several areas, especially in the Serranía del Interior, were the Morros de San Juan offer a characteristic landscape feature. The calize rocks in the proximity’s of Caripe have originated the Guácharo cave, the most famous karstic formation of Venezuela. Soils are generally acidic and predominantly entisols and ultisols; nutrient levels are generally low with exception of certain soils localized in the valleys around Valencia Lake.

The climate of the Cordillera de la Costa is strongly influenced by the north-eastern trade winds, specially during the dry season from December to April, whereas during the rainy season the Intertropical Convergence Zone (ITCZ) reaches its northern winds with high moisture. In the montane forest, the climate consists of prehumid mesothermic conditions (average annual temperature 10°–20°C and rainfall between 1,000–3,000 millimeters). Frequent mist occurs above about 800 m on the windward, and 1,000 m on the leeward slopes, and it extends up to 1,000–1,200 m.

According to Huber, this ecoregion includes three forest types: evergreen transition forests, evergreen montane cloud forests, and upper montane elfin forest. Evergreen transition forests, ranging from 600 to 900 m, form a narrow belt between the lower montane semideciduous forests and upper montane forests, or ever green montane cloud forest. Here the giant endemic Gyranthera caribensis (up to 60 m tall) form small stands emerging above the general forest canopy dominate by Trophis racemosa, Ficus macbridei, Tetragastris caracasana, Zanthoxylum ocumarense, Banara nitida, etc. The understory is dominated by shrubs of Aphelandra micans, Besleria disgrega, Psycotria macrophylla, and Hoffmannia apodantha, together with large colonies of giant herbs such as Musaceae (Heliconia bihai, H. revoluta), Araceae (Dieffenbachia maculata), Marantaceae, and many ferns.

Evergreen montane cloud forests, extending from 1,000 to 2,200 m, are the most species-rich plant communities of the entire Cordillera de la Costa. They are irregularly structured in 2–3 canopy layers with a main canopy extending up to 15–20 m. Canopy trees include Ecclinusa abbreviata, Graffenrieda latifolia, and Ocotea spp. Palms are very frequent in the canopy and in the understory as well, either growing solitarily (Dictyocarium sp., Socratea sp., Geonoma spp.) or in large, sometimes monodominant clumps (Hyospathe pittieri, Catoblastus praemorsus, Bactris sp.). Epiphytes (ferns, orchids, bromeliads, ericads, and gesneriads) and terrestrial ferns are very abundant, and shrub and herb layer is usually dense and dominated by endemic species.

Upper montane elfin forest and scrub, resembling in some instances the sub-paramo belt of the Andes, is found above 2,000–2,400 m. Here, the open scrub is dominated by the primitive espeletioid composite, Libanothamnus neriifolius, and show an irregular but often rather dense herbaceous layer; while in the low mossy forest the trees Clusia multiflora, Weinmannia spp., and Prumnopitys harmsiana, are the most frequent.

This general pattern in the distribution of vegetation due to elevation is common in most of the mountains of the Cordillera de la Costa. In some regions, such as the mountains of the Peninsula of Paria, exposure to the prevailing winds makes strong modifications in the local conditions of humidity and temperature, allowing lower montane evergreen forests to start at 400 m above sea level. Other examples are the modifications in the vegetation patterns present in the slopes of the mountains of El Ávila National Park, and other mountains of the region, where the original forest vegetation had been substituted by open vegetation, like savannas, that display a strong component of exotic grasses.

Biodiversity Features

Table 1. Vertebrate endemic species of the Cordillera de la Costa Montane Forests
Endemic species Western Cordillera Eastern Cordillera
Birds1
Rusty-flanked Crake Laterallus levraudi ?  
Scissor-tailed Hummingbird
Hylonympha macrocerca
  ?
Black-throated Spinetail
Synallaxis castanea
?  
White-throated Barbtail
Premnoplex tatei
  ?
Guttulated Foliage-
cleaner Syndactyla guttulata
? ?
Scallop-breasted Antpitta
Grallaricula loricata
?  
Handsome Fruiteater
Pipreola formosa
? ?
Venezuelan Bristle-tyrant
Phylloscartes venezuelanus
?  
Rufus-cheeked Tanager
Tangara rufigenis
?  
Venezuelan Flowerpiercer
Diglossa venezuelensis
  ?
Paria Whitestart
Myoborus pariae
  ?
Grey-headed Wabler
Basileuterus griseiceps
  ?
Mammal2
Ichtyomys pittieri ?  
Frogs3
Atelopus cruciger ?  
Cochranella castroviejoi   ?
C. vozmedianoi   ?
Hyalinobatrachium antisthenesi ?  
Colosthetus bromericola ?  
C. dunni ?  
C. mandelorum   ?
Mannophryne neblina ?  
M. riveroi   ?
Gasthroteca ovifera ?  
G. walkeri ?  
G. williamsoni ?  
Hyla battersbyi ?  
H. luteo-ocellata ?  
Phyllomedusa medinai ?  
Eleutherodactylus bicumulus ? ?
E. maussi ? ?
E. reticulatus ?  
E. rozei ?  
E. stenodiscus ?  
E. turimiquiensis   ?
Reptiles4
Gonadotes taniae ?  
Anadia marmorata ?  
Euspondylus acuatirostris ?  
Proctoporus achlyens ?  
Anolis tigrinus ?  
Atractus lancinii ?  
Atractus vittatus ?  
Chironius multiventris ?  
Dendrophidion nuchalis ?  
Liophis williamsi ?  
Rhadinaea multimineata ?  
1 Stattersfield (1998)
2 Linares (1998)
3 Barrio (1996) and Frost (1985)
4 Manzanilla et al (1996). In this section of the table I only include endemic reptiles of the western Cordillera de la Costa registered in the Henri Pittier National Park.
caption Tamandua. (Photograph by Edward Mendell)

The Cordillera de la Costa montane forests are rich in species and are considered the most important endemic zones for flora and fauna in Venezuela. It would appear that the primary factor for determining this grade of endemism is mainly related to the establishment of topographic barriers that separate the Cordillera de la Costa with these other two mountainous systems.

Phytogeographycally, the flora of the Cordillera de la Costa shows a stronger relationships with the Mesoamerican and Caribbean floristic regions than with the northern Andean flora and the Guayanan flora. A survey of endemic plant species registered a total of 247. According to this survey, the dispersal centers of the two cordilleras (western and eastern) showing the greatest number of endemic species are Naiguatá with 69 species, Rancho Grande with 40, Guácharo (Caripe) with 38, Turimiquire with 37, and Paria with 29. However, other botanical studies have shown important differences in the values of endemism for the same areas, revealing the need for more botanical research to have better estimates of endemic species.

Endemic birds in the Cordillera de la Costa are also relevant. A total of 12 bird species are restricted to the entire ecoregion (Table 1) Five of them are exclusive of the western cordillera, and another five to the eastern cordillera, with two species common to both sections. The eastern Cordillera also includes 45 endemic subspecies, 13 of which are confined to the Paria peninsula. The number of Andean-derived bird species in the various coastal mountain ranges decreases from west to east, with the minimum number in the Paria Peninsula. All the eastern region endemic birds are considered threatened species. The scissor-tailed hummingbird (Hylonimpha macrocerca), paria whitestart (Myioborus pariae), Venezuelan flower-piercer (Diglosa venezuelensis), and grey-headed warbler (Basileuterus griseiceps) are in critical danger, and white-throated barbtail (Premnoplex tatei) is endangered. In the western portion the endemic rusty-flanked crake (Laterallus levraudi) and the northern helmeted curassow (Pauxi pauxi), common to other ecoregions, are vulnerable and endangered respectively. Other non-endemic bird distributed along the western region of the Cordillera, such as the harpy eagle (Harpia harpia) and the military macaw (Ara militaris), are considered vulnerable at national level.

Bird migration from north and south has been registered during boreal autumn (August-October) and spring (March-April) in Henri Pittier National Park. The Peregrine falcon (Falco peregrinus) and the broad-winged Hawk (Buteo platypterus) have been observed during the last 10 years at Paso Periquito located in the lowest point of the mountain range. Eighteen other migrant species have been registered during this time.

The ecoregion has one endemic mammal registered, Ichtyomys pittieri- a fish-eating rat, confined to the western region of the cordillera. There are also four insectivore non-endemic species of bats (Thyroptera discifera, Myotis keaysi, Molossus bondae, and Tadarida aurispinosa) that are found in other neotropical regions excluding Venezuela.

There is not enough information about the herpetofauna of the Cordillera de la Costa. The existent available information is based on isolated captures, so the number of specimens and ecological data of many species is insufficient. Although more studies on the herpetofauna are necessary, the Cordillera de la Costa Montane Forests is considered as a region with great endemism. At least 21 species of frogs and 11 species of reptiles are recognized to be endemic to this region (Table 1). The endemic frog, Atelopus cruciger, was once abundant in the cloud forests of the Cordillera de La Costa. Today this amphibian is the first frog declared endangered in Venezuela. The frog has disappeared from protected areas like Henri Pittier and San Esteban parks (last registered in the late 80s). The fast decline in its population has been related to the global decline of amphibians, and specifically to the decline of other species of Atelopus in the Andes.

Current Status

The remaining fragmented montane forests are restricted to higher elevations, where the pronounced slopes are difficult to access. The ecoregion includes 11 National Parks: Yurubí of 237 km2 (IUCN category II), Henri Pittier of 1,225 km2 (IUCN category II), San Esteban of 435 km2 (IUCN category II), El Avila of 852 km2 (IUCN category II), Macarao of 150 km2, Guatopo of 1,225 km2, El Guacharo of 627 km2 (IUCN category II), Peninsula de Paria of 375 km2 (IUCN category II), and five Natural Monuments: Pico Codazi of 119 km2 (IUCN category III), Cueva Alfredo Jahn of 0.6 km2 (IUCN category III), Alejandro Humbolt of 1.8 km2 (IUCN category III), Juan Germán Rocio o Cerro Platillon of 80 km2 (IUCN category III), and Morros de Macaira of 1 km2 (IUCN category III). Governmental protection is deficient, and most of the protected areas are threatened (even National Parks), except for El Avila, Henri Pittier, and Pico Codazi.

Types and Severity of Threats

Deforestation due to shifting cultivation has been responsible for most of the destruction of the original forests on the lower and middle mountain slopes. One of the areas most heavily affected by shifting cultivation is the Cerro Turimiquire and the Cerro Peonía in the eastern section. Likewise, the lower montane forests of Peninsula de Paria, where habitat destruction is still proceeding at an alarming rate, are being altered and settled following the completion of a road leading to Macuro. Deforestation in other areas is also caused by construction of tourist and recreation resorts in the vicinity of the larger cities, which also involves intensive road building into previously inaccessible areas.

A major threat to the remaining forests are frequent fires lit during the dry season in the already deforested and mostly savanna-covered, surrounding lower areas. Although fires usually do not penetrate into the cloud forest itself, in some place the adjacent montane evergreen forests are being severely reduced.

Another important threat is the selective extraction of some plant species of commercial value. Even though no known Venezuelan plant species has yet been exterminated, some of them are certainly either endangered or threatened. This is especially true for some species of orchids of genus Oncidium, Cycnoches, Schomburgkia, Brassavola, Encyclia, Lycaste many species of Catteya, and the species Masdevallia tovarencis (endemic of the central portion of the Cordillera de la Costa). Also tree ferns, whose trunks are made into hanging baskets to grow orchids, are in great demand.

Finally, shifting hunting and presence of great number of introduced animals that feed in small mammals and birds, are also an important threat to the fauna. This situation especially occurs in those areas that are located near populated areas.

Justification of Ecoregion Delineation

These patches of montane forest occur in a mosaic of xeric habitats which predominate northern Venezuela, and are therefore refuges for many species – including a high percentage of endemic species. Delineation’s were derived from Huber, and linework was modified following the expert opinion of Smith, whose extensive experience in the area help make critical distinctions between original and current vegetation cover. This archipelago of moist forests are generally characterized by distinct elevational changes, creating a gradient in climate and, therefore, flora and fauna.

Additional Information on this Ecoregion

Further Reading

  • Barrios, C. L. 1998. Sistemática y Biogeografía de los Anfibios (Amphibia) de Venezuela. Acta Biológica Venezuelica, 18(2): 1-93.
  • Cracraft, J. 1985. Historical biogeography and patterns of differentiation within the South American Avifauna: areas of endemism. Pages 49-84 in P.A. Buckley, M.S. Foster, E.S. Morton, R.S. Ridgely and F.G. Buckley, editors. Neotropical Ornithology. Ornithological Monographs, No. 36. ISBN: 0943610443
  • Fernandez-Badillo, A. and M. Ulloa, 1990. Fauna del Parque Nacional Henri Pittier, Venezuela: Composición y Deversidad de la Mastofauna. Acta Cientifica Venezolana, 41:50-63.
  • Frost, D., editor. 1985. Amphibian species of the world:. A taxonomic and biogeographic reference. Allen Press Inc. and The Association of Systematics Collections. Lawrence, Kansas, USA.
  • Huber, O., and C. Alarcon. 1988. Mapa de vegetación de Venezuela. 1:2,000,000. Ministerio del Ambiente y de los Recursos Naturales Renovables, Caracas, Venezuela.
  • Huber, O.1996. Bosques montanos de la Cordillera de la Costa. D. Olson, E. Dinerstein, G. Castro and E. Maraví, editors. Identificación de vacíos de información botánica para la conservación de la biodiversidad en América Latina y el Caribe. Memorias del taller llevado a cabo entre el 7 y el 9 de abril de 1996 en Washington D.C. y consultas con los especialistas de la región.
  • Huber, O.1997. Coastal Cordillera, Venezuela. Pages 308-311 in Davis, S.L.D, V.H. Heywood, O. Herrera-MacBryde, J. Villa-Lobos and A.C. Hamilton, editors. Centres of plant diversity: a guide and strategy for their conservation. Vol. 3. The Americas. World Wildlife Fund (WWF) y The World Conservation Union - IUCN. IUCN Publications Unit, Cambridge, U.K. ISBN: 2831701996
  • Huber, O. and D. Frame. 1989. Venezuela. Pages 362-374 in D.G. Campbell and H.D. Hammond, editors. Floristic inventory of tropical countries: The status of plant systematics, collections, and vegetation, plus recommendations for the future. The New York Botanical Garden, New York. USA. ISBN: 0893273333
  • Huber, O., R. Duno, R. Riina, F. Staufer, L. Pappaterra, A. Jiménez , S. Llasmozas and G. Orsini. 1998. Estado actual del conocimiento de la flora de Venezuela. Documentos técnicos de la Estrategia Nacional Diversidad Biológica No. 1. Fundación Instituto Botánico de Venezuela. Ministerio del Ambiente y los Recursos Naturales Renovables. Estrategia Nacional de Diversidad Biológica. Caracas, Venezuela.
  • La Marca, E.,and S. Lotters. 1997. Monitoring of declines in Venezuelan Atelopus (Amphibia: Anura: Bufonidae. Herpetologia Bonnensis. W. Bohme, W. Bischoff, and Z. Thomas, editors. Proceedings of the 8th Ordinary General Meeting of the Societas Europaea Herpetologica, 23-27 August 1995, Bonn, Germany. Societas Europaea Herpetologica, Bonn.
  • Linares, O. 1998. Mamíferos de Venezuela. Sociedad Conservacionista Audubon de Venezuela. Caracas.
  • Long, A.J. 1995. The importance of tropical montane cloud forests for endemic and threatened birds. Pages 79-106 in L.S. Hamilton J.O. Juvik, and F.N. Scatena, editors. Tropical montane cloud forests. Ecological studies, Vol. 110. Springer-Verlang. ISBN: 0387943234
  • Manzanilla, J., A. Fernández-Badillo, E. La Marca and R. Visbal. 1995. Fauna del Parque Nacional Henri Pittier, Venezuela: Composición y Distribución de los Anfibios. Acta Científica Venezolana, 46 (4): 294-302.
  • Manzanilla, J., A. Fernández-Badillo, E. La Marca and R. Visbal. 1995. Fauna del Parque Nacional Henri Pittier, Venezuela: Composición y Distribución de los Reptiles. Acta Científica Venezolana, 47 (3): 191-204.
  • Moore, N. and J. Beament J. 1989. Cambridge Columbus Zoological Expedition to Venezuela. Cambridge, U.K.
  • PDVSA. 1995. Imagen de Venezuela, una visión espacial. Third edition. Petróleos de Venezuela, S.A.. Caracas, Venezuela. ISBN: 980259475X
  • Rodriguez, J.P. and F. Rojas-Suarez. 1997. Libro rojo de la fauna venezolana. Second ed. Provita, Fundación Polar, Wildlife Conservation Society, Profauna-M.A.R.N.R., UICN. Ex Libris, Caracas. ISBN: 9806100972
  • Salas, V., M. Lentino M. and E. Fernandez. 2000. Bird-banding in Henri Pittier National Park. Sociedad Conservacionista Audubon de Venezuela, Colección Ornitológica Phelps, Sociedad Científica Amigos del Parque Nacional Henri Pittier. Informe entregado a los patrocinantes.
  • Smith, R.F. Personal communications. June 16, 1994. Letters concerning the classification of N. Venezuelan ecoregions.
  • Stattersfield, A.J., M.J. Crosby, A.J. Long, and D.C. Wege, editors. 1998. Endemic bird areas of the world. Priorities for biodiversity conservation. Birdlife Conservation Series No. 7. BirdLife International. Cambridge, U.K.
  • Steyermark, J.A. 1977. Future outlook for threatened and endangered species in Venezuela. Pages 128-135 in Prance, G.T. and T. S. Elias, editors. Extintion is forever. The New York Botanical Garden. New York, USA.
  • Steyermark, J.A.1979. Plant refuge and dispersal centres in Venezuela: their relict and endemic element. Pages 185-221 in K. Larsen and L.B. Holm-Nielsen, editors. Academic Press. Great Britain, London.
  • Wege, D.C. and A.J. Long. 1995. Key areas for threatened birds in the neotropics. Bird Conservation series No. 5. BirdLife International. Cambridge, U.K. ISBN: 0946888310
  • Zalles, J.L. and K.L. Bildstein. 2000. Raptor watch: A Global Directory of Raptor Migration Sites. BirdLife Conservation Series No. 9. BirdLife International. Cambridge, U.K. ISBN: 0946888388


 

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Fund, W. (2014). Cordillera La Costa montane forests. Retrieved from http://www.eoearth.org/view/article/151497

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