The Sierra de Lema is an

upland Upland or Uplands may refer to: Geography *Hill, an area of higher land, generally *Highland, an area of higher land divided into low and high points *Upland and lowland, conditional descriptions of a plain based on elevation above sea level *I ...

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 aris ...

area with

tepui A tepui , or tepuy (), is a member of a family of table-top mountains or mesas found in northern South America, especially in Venezuela, western Guyana, and northern Brazil. The word tepui means "house of the gods" in the native tongue of the ...

s, located in Bolívar state of southeastern

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

. 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, and biogeographically part of the

Guayana Highlands Guyana is a country in the Guianas, South America. Guyana, Guiana, or Guayana may refer to: * British Guiana, a British colony until 1966, now independent and known as Guyana * French Guiana, an overseas department of France in the Guianas * The ...

. Lying north of the

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

, 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 single ...

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 confluenc ...

and Cuyuni River

drainage basin A drainage basin is an area of land in which 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, ...

s. It is partly within the bounds of

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

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

s, including the entire

Los Testigos Los Testigos, also known as the Aparamán range, is a mountain chain in Bolívar, Venezuela, Bolívar, Venezuela.Huber, O. (1995). Geographical and physical features. In: P.E. Berry, B.K. Holst & K. Yatskievych (eds.) ''Flora of the Venezuelan G ...

chain and

Ptari Massif Ptari-tepui, also spelled Pu-tari and sometimes called Cerro Budare or Cerro del Budare, is a tepui in Bolívar state, Venezuela. Lying near the centre of the Sierra de Lema, Brewer-Carías, C. (2012)La Sierra de Lema: una bisagra de vida ''Río ...

. The elevational range of the Sierra de Lema is around

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

.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 na ...

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 watercourses join to form a single channel (geography), channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main ...

of the

Paragua River The Paragua River is a river of Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, isl ...

and

Ecology

The

old-growth forest An old-growth forest or primary forest is a forest that has developed over a long period of time without disturbance. Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organization of the United Natio ...

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 (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

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 numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

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 nucle ...

, 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, is a generally tropical or subtropical, evergreen, Montane forest, montane, Tropical and subtropical moist broadleaf forests, moist forest characteri ...

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 ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial ...

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, causi ...

basement A basement is any Storey, floor of a building that is not above the grade plane. Especially in residential buildings, it often is used as a utility space for a building, where such items as the Furnace (house heating), furnace, water heating, ...

overlain by

Precambrian The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, 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 t ...

sedimentary rock Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or de ...

s of the Roraima Group, with

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

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-gra ...

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

* by

Charles Brewer-Carías Charles Brewer-Carías (born 10 September 1938 in Caracas, Venezuela) is a Venezuelan explorer and naturalist. Known as the " Humboldt of the twentieth century", Brewer-Carías has led more than 200 expeditions to remote parts of the Venezuelan ...

{{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