Resumen

SANCHEZ SILVA, Rubén; LOPEZ GARCIA, José  y  ESPINOZA RDZ., José Manuel. Pinus culminicola Andresen y Beaman y sus asociaciones en la ladera sur del cerro La Viga, Coahuila. Invest. Geog [online]. 1990, n.21, pp.21-43. ISSN 2448-7279.

Pinus culminicola was described in 1961 with samples from the Cerro Potosí, State of Nuevo León, Mexico. The species was reported in the Sierras La Marta in 1962, and San Antonio de las Alazanas in 1975, State of Coahuila, indicating that there were not pure associations. In 1979 the species was colected in the Sierra La Viga, Coahuila, at 3 300 m, without data on environmental conditions in which it grows. The distribution of P. culminicola is restricted to the south slope of the Cerro La Viga. The associations identified and described in this paper are: (1) Scrub of Quercus rugosa - Quercus durifolia - Cercocarpus montanus with elements of P. culminicola; (2) Pinus montezumae-Pseudotsuga macrolepisy with elements of P. culminicola, Quercus spp. and Arbutus xalapensis (3) P. culminicola- Quercus rugosa (both of them as shrubs); (4) P. montezumac-P. macrolepis-Pinus ayacahuite-P. culminicola; (5) pure scrub of P. culminicola; (6) P. culminicola- Dasylirion tezanum (sometimes with Arctostaphylos pungens and Quercus spp., shrublike; (7) Pinus hartwegii-P. culminicola; (8) P. hartwegii with elements of P. macrolepis and P. culminicola; and (9) induced prairie. There are differences in dominance of the species in accordance to the particular characteristics of each place, with presence of herbaceous from high altitudes. The altitude at which these associations occur, varies from 2 900 m to 3 700 m, although isolated elements of P. culminicola-were found at 2 700 m.

Palabras llave : Pinus culminicola Andresen and Beaman; Cerro La Viga; Coahuila; dwarf pinyon; dwarf pine; cespitose thicket; pine thicket; shrubby pine.