The Sierra de Lema is an upland

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...

area with

tepui A tepui , or tepuy (), is a table-top mountain or mesa found in South America, especially in Venezuela and western Guyana. The word tepui means "house of the gods" in the native tongue of the Pemon, the indigenous people who inhabit the Gran S ...

s, located in Bolívar state of southeastern

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

. The names Sierra Rinocote and Sierra Usupamo have historically been applied to its eastern and western portions, respectively.

Geography

The Sierra de Lema is geologically part of the

Guayana Shield The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a ...

, and biogeographically part of the

Guayana Highlands Guyana is a country in the Guianas, South America. Guyana, Guiana, or Guayana may refer to: * French Guiana, an overseas department of France in the Guianas * The Guianas, a region in the north of South America * Guayana Region, an administrative ...

. Lying north of the

Gran Sabana La Gran Sabana (, en, The Great Savanna) is a region in southeastern Venezuela, part of the Guianan savanna ecoregion. The savanna spreads into the regions of the Guiana Highlands and south-east into Bolívar State, extending further to the bo ...

, it marks the

drainage divide A drainage divide, water divide, ridgeline, watershed, water parting or height of land is elevated terrain that separates neighboring drainage basins. On rugged land, the divide lies along topographical ridges, and may be in the form of a singl ...

between the

Caroní River The Caroní River is the second most important river of Venezuela, the second in flow, and one of the longest, from the Kukenan tepui through to its confluence with the Orinoco River. The name "Caroní" is applied starting from the confluence ...

and

Cuyuni River The Cuyuni River is a South American river and a tributary of the Essequibo River. It rises in the Guiana Highlands of Venezuela, where it descends northward to El Dorado, and turns eastward to meander through the tropical rain forests of the Cu ...

drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...

s. It is partly within the bounds of

Canaima National Park Canaima National Park ( es, Parque Nacional Canaima) is a park in south-eastern Venezuela that roughly occupies the same area as the Gran Sabana region. It is located in Bolívar State, reaching the borders with Brazil and Guyana. History Ca ...

Torres, I.N. & D.D. Martín (November 2007). Mejorando Nuestra Herencia. and encompasses a number of prominent

s, including the entire

Los Testigos LOS, or Los, or LoS may refer to: Science and technology * Length of stay, the duration of a single episode of hospitalisation * Level of service, a measure used by traffic engineers * Level of significance, a measure of statistical significanc ...

chain and Ptari Massif. The elevational range of the Sierra de Lema is around

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

.Huber, O. (1995). Geographical and physical features. In: P.E. Berry, B.K. Holst & K. Yatskievych (eds.) '' Flora of the Venezuelan Guayana. Volume 1. Introduction.'' Missouri Botanical Garden Press, St. Louis. pp. 1–61.Durán Rangel, C., A. Reif & L. Hernández (April 2011)
Understanding small-scale disturbances in Guayana's montane forests: gap characterization in the Sierra de Lema, Venezuela.
''Interciencia'' 36(4): 272–280. The chain of

mountains that comprises the Sierra de Lema is around wide. Brewer-Carías, C. (2012)
La Sierra de Lema: una bisagra de vida
''Río Verde'' 7: 73–86. Because the

toponymy Toponymy, toponymics, or toponomastics is the study of ''toponyms'' (proper names of places, also known as place names and geographic names), including their origins, meanings, usage and types. Toponym is the general term for a proper name of ...

of the region remains largely unresolved, the stated ''length'' of the Sierra de Lema can vary widely, depending on the definition used. When considering only the uplands that mark the northern boundary of the Gran Sabana, the Sierra de Lema spans around . The extent of the range exceeds if the entire chain separating the Caroní and Cuyuni drainage basins is included. By the latter definition, the Sierra de Lema stretches from Cerro Venamo in the east to Serranía Supamo and Cerro Santa Rosa (mountain) in the west, very close to the

confluence In geography, a confluence (also: ''conflux'') occurs where two or more flowing bodies of water join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main stem); o ...

of the

Paragua River The Paragua River is a river of Venezuela. It is part of the Orinoco River basin. It is the largest tributary of the Caroní River. The river drains the Guayanan Highlands moist forests ecoregion. See also *List of rivers of Venezuela This is ...

and

Ecology

The

old-growth forest An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological featur ...

section of the Sierra de Lema, in the Guayanan Highlands moist forests ecoregion, remains virtually intact. It covers a contiguous area of some . It is characterised by nutrient poor soils with a low pH and high

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

content. The ''El Mirador'' ("The Lookout") area at the base of the Sierra de Lema exhibits unusually high levels of the

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

Caesium-137 Caesium-137 (), cesium-137 (US), or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nucl ...

, in both its soils and vegetation.LaBrecque, J.J., J.A. Alfonso & P.R. Cordoves (August 2008). Anomalously high activities of ¹³⁷Cs in soils and vegetation on and near a diabase outcrop in La Sierra de Lema, Venezuela. ''Journal of Radioanalytical and Nuclear Chemistry'' 277(2): 405–411. This is likely related to the ground composition and

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...

conditions of the site. The undulating, forested landscape of La Escalera ("The Staircase") also forms part of the Sierra de Lema.Hernández, L., N. Dezzeo, E. Sanoja, L. Salazar & H. Castellanos (March 2012)
Changes in structure and composition of evergreen forests on an altitudinal gradient in the Venezuelan Guayana Shield
''Revista de Biología Tropical'' 60(1): 11–33.

Geology

The Sierra de Lema consists of an

igneous Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

basement A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, ...

overlain by

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

s of the Roraima Group, with

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo ...

diabase Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-graine ...

intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

References

* Aymard Corredor, G.A. & E. Sanoja (December 2012). A new species of ''Ormosia'' (Leguminosae: Papilionoideae, Sophoreae) from the Guayana Shield, Bolivar State, Venezuela. ''Harvard Papers in Botany'' 17(2): 275–279. * Barrio-Amorós, C.L. & W.E. Duellman (2010). Anfibios y reptiles de la Sierra de Lema, Venezuela. Parte I: Anuros de las familias Bufonidae e Hylidae. ''Reptilia: revista especializada en reptiles, anfibios y artrópodos'' 82: 26–33. * Barrio-Amorós, C.L. & W.E. Duellman (2010). Anfibios y reptiles de la Sierra de Lema, Venezuela. Parte II: Anuros de las familias Centrolenidae, Dentrobatidae, Leptodactylidae, Microhylidae y Pipidae. ''Reptilia: revista especializada en reptiles, anfibios y artrópodos'' 83: 64–70. * Barrio-Amorós, C.L. & W.E. Duellman (2010). Anfibios y reptiles de la Sierra de Lema, Venezuela. Parte III: Saurios y quelonios terrestres. ''Reptilia: revista especializada en reptiles, anfibios y artrópodos'' 84: 32–38. * Barrio-Amorós, C.L. & W.E. Duellman (2010). Anfibios y reptiles de la Sierra de Lema, Venezuela. Parte IV: Ofidios. ''Reptilia: revista especializada en reptiles, anfibios y artrópodos'' 85: 55–61. * Barrio-Amorós, C.L., C. Brewer-Carías & O. Fuentes-Ramos (31 April 2011)
Aproximación preliminar a la herpetocenosis de un bosque pluvial en la sección occidental de la Sierra de Lema, Guayana Venezolana
''Revista de Ecología Latinoamericana'' 16(1): 1–46. * Brewer-Carías, C. (2007). ''La Sierra de Lema''. Fundación Wonken, Caracas. * De Marmels, J. (1983). The Odonata of the region of Mount Auyantepui and the Sierra de Lema, in Venezuelan Guyana. 3. Additions to the families Gomphidae, Aeshnidae and Corduliidae, with description of ''Progomphus racenisi'' spec. nov.. ''Odonatologica'' 12(1): 1–13. * Durán Rangel, C. (2001)
Estructura y composición florística de los bosques de Sierra de Lema, con especial énfasis en ''Pourouma bolivarensis'' C.C. Berg
Internship report, Universidad de los Andes, Mérida. * Durán Rangel, C. & A. Reif (February 2006). Cloud forest gap structure in Sierra de Lema, Gran Sabana, Venezuela. In
''I Congreso Internacional de Biodiversidad del Escudo Guayanés: Programa y Libro de Resúmenes''.
Universidad Nacional Experimental de Guayana, Puerto Ordaz. p. 99. * Echagaray, M. & L. Aguirre (2003). Dinámica y crecimiento en bosques en un gradiente climático desde Sierra de Lema hasta la Gran Sabana. Una red de parcelas permanentes. Degree thesis, Universidad Nacional Experimental de Guayana, Puerto Ordaz. * Hernández, L. (2005). Crecimiento diamétrico de árboles en bosques a lo largo de un gradiente climático entre Sierra de Lema y la Gran Sabana: resultados preliminares. ''Saber'', supplement 17: 213–214. * Hernández, L. & J. Ortíz (2004). Avances del estudio sobre dinámica de bosques a lo largo de un gradiente climático entre Sierra de Lema y la Gran Sabana. In: ''Memorias IV Congreso Forestal Venezolano: Bosque Vida y Desarrollo''. Ministerio del Ambiente y de los Recursos Naturales, Barinas. * Hernández, L., E. Sanoja, L. Salazar, H. Durán & M. Echagaray (February 2006). Monitoreo de comunidades boscosas a lo largo de un gradiente climático al sudeste de la Guayana Venezolana. orest community monitoring along a climatic gradient in the southeast of the Venezuelan Guayana.In
''I Congreso Internacional de Biodiversidad del Escudo Guayanés: Programa y Libro de Resúmenes''.
Universidad Nacional Experimental de Guayana, Puerto Ordaz. p. 93. * Hernández, L. & H. Castellanos (November 2006)
Crecimiento diamétrico arbóreo en bosques de Sierra de Lema, Guayana Venezolana: primeras evaluaciones.
ree diameter growth in forests at Sierra de Lema, Venezuelan Guayana: initial evaluations.''Interciencia'' 31(11): 779–786. * Hernández, L., E. Sanoja, C. Durán, J. Ayala, J. Ortíz, L. Salazar, M. Echagaray, N. Dezzeo, W. Meier, L. Aguirre, P Rodríguez, J.C. González, L. Delgado, G. Rodríguez & H. Castellanos (2011)
Estudio a largo plazo de la dinámica de bosques en un gradiente altitudinal al sudeste de la Guayana Venezolana.
''BioLlania Edición Especial'' 10: 63–73. * Keller, R. (February 2006). Identifying trees of the Sierra de Lema (State of Bolívar) by means of bark characteristics and using a laptop computer application. In
''I Congreso Internacional de Biodiversidad del Escudo Guayanés: Programa y Libro de Resúmenes''.
Universidad Nacional Experimental de Guayana, Puerto Ordaz. pp. 140–141. * Lew, D. & R. Pérez-Hernández (2004) 2003'br>Una nueva especie del género ''Monodelphis'' (Didelphimorphia: Didelphidae) de la Sierra de Lema, Venezuela.
new species of the genus ''Monodelphis'' (Didelphimorphia: Didelphidae) from Sierra de Lema, Venezuela.''Memoria de la Fundación La Salle de Ciencias Naturales'' 159–160: 7–25. * Machado-Allison, A., B. Chernoff, R. Royero-León, F. Mago-Leccia, J. Velázquez, C. Lasso, H. López-Rojas, A. Bonilla-Rivero, F. Provenzano & C. Silvera (January–February 2000)
Ictiofauna de la cuenca del Río Cuyuní en Venezuela.
''Interciencia'' 25(1): 13–21. * Méndez, S. (2006). Caracterización anatómica de la madera, con fines de análisis dendrocronológico de 8 especies provenientes de un bosque húmedo premontano alto ubicado en la parte alta de La Escalera, Sierra de Lema, Estado Bolívar. Internship report, Universidad Nacional Experimental de Guayana, Puerto Ordaz. * Mujica, N. (2007). Determinación de la densidad de madera de especies arbóreas un bosque nublado de La escalera (Sierra de Lema). Degree thesis, Universidad Nacional Experimental de Guayana, Puerto Ordaz. * Ortíz G., J.C. (November 2002)
Ensayo de técnicas dendrocronológicas en los géneros tachigali y terminalia en bosques semideciduos y siempre-verdes de tierras bajas entre el Dorado y Sierra de Lema, Estado Bolívar
Degree thesis, Universidad Nacional Experimental de Guayana, Puerto Ordaz. * Ortiz, J., E. Sanoja & S. Méndez (February 2006). Caracterización anatómica de 8 especies con fines de análisis dendrocronológico del bosque húmedo premontano alto ubicado en la parte alta de Sierra de Lema, Estado Bolívar. natomical characterization of 8 species with the intention of dendrochronological analysis of a high premontan humid forest in the upper Sierra de Lema, State of Bolívar.In
''I Congreso Internacional de Biodiversidad del Escudo Guayanés: Programa y Libro de Resúmenes''.
Universidad Nacional Experimental de Guayana, Puerto Ordaz. p. 207. * Rácenis, J. (May–August 1968). Los odonatos de la región del Auyantepui y de la Sierra de Lema, en la Guayana Venezolana. 1. Superfamilia Agrionoidea. ''Memoria de la Sociedad de Ciencias Naturales La Salle'' 28(80): 151–176. * Rácenis, J. (1970). Los odonatos de la región del Auyantepui y de la Sierra de Lema, en la Guayana Venezolana. 2. Las familias Gomphidae, Aeshnidae y Corduliidae. ''Acta Biologica Venezuelica'' 7(1): 23–39. * Rodríguez, P. (February 2008)
Inventario dendrológico de bosques a lo largo de un gradiente altitudinal en La Escalera, Sierra de Lema
Degree thesis, Universidad Nacional Experimental de Guayana, Puerto Ordaz. * Sanoja, E. (2004)
Diagnosis y observaciones sobre la biología de ''Catostemma lemense'', nueva Bombacaceae de Venezuela
iagnosis and observations on the biology of ''Catostemma lemense'', new Bombacaceae of Venezuela.''Acta Botánica Venezuelica'' 27(2): 83–94. * Sanoja, E. (2008). Caracterización fisonómica y dendrológica de bosques montanos en La Escalera, Sierra de Lema, Estado Bolívar. Promotion research study, UUniversidad Nacional Experimental de Guayana, Puerto Ordaz. * Sanoja, E., L. Hernández, B. Holst, W. Díaz, M. Calzadilla & L. Salazar (February 2006). Estado actual del conocimiento dedrotaxonómico de los bosques premontanos de La Escalera, Sierra de Lema, Estado Bolívar - Venezuela. ctual status of dedrotaxonomic knowledge of La Escalera premontan forests, Sierra de Lema, State of Bolívar - Venezuela.In
''I Congreso Internacional de Biodiversidad del Escudo Guayanés: Programa y Libro de Resúmenes''.
Universidad Nacional Experimental de Guayana, Puerto Ordaz. pp. 139–140. * Sanoja, E. (June 2009)
Lista dendrológica de los bosques montanos de La Escalera, Sierra de Lema, Estado Bolívar, Venezuela
endrological list of montane forests of La Escalera, Sierra de Lema, Bolivar State, Venezuela.''Acta Botánica Venezuelica'' 32(1): 79–111. * Sanoja, E. (December 2009)
Nueva especie de ''Zanthoxylum'' L. (Rutaceae) de Sierra de Lema, Estado Bolívar, Venezuela
new species of ''Zanthoxylum'' L. (Rutaceae) from Sierra de Lema, Bolívar state, Venezuela.''Acta Botánica Venezuelica'' 32(2): 303–310. * Steyermark, J.A., S. Nilsson & collaborators (1962). Botanical novelties in the region of Sierra de Lema, Estado Bolívar, Venezuela – I. ''Boletín de la Sociedad Venezolana de Ciencias Naturales'' 23(101): 59–95. * Steyermark, J.A. (1966). Botanical novelties in the region of Sierra de Lema, Estado Bolívar, Venezuela – III. ''Boletín de la Sociedad Venezolana de Ciencias Naturales'' 26(110): 411–452.

External links

*
La Sierra de Lema una bisagra de vida
by Charles Brewer-Carías {{Tepuis , Venezuela Mountain ranges of Venezuela Guayana Highlands Landforms of Bolívar (state) Tepuis of Venezuela

Geography

Ecology

Geology

See also

References

Further reading

External links