José Ángel Villarreal Quintanilla

Leguminosas del norte del estado de Nuevo León, México

A study of the diversity of legumes in the northern part of the state of Nuevo Leon was undertaken. 38 genera, 94 species and 26 infraspecific taxa of legumes were recorded. The family Fabaceae comprises 18 genera and 42 species, Mimosaceae 10 and 30 and Caesalpiniaceae 10 and 22 respectivelly. The genera with highest number of species are Acacia (12), Dalea (10), Mimosa (6), Senna (5), Caesalpinia (4) and Bauhinia (4). Shrubby legumes are the most abundant in the zone, representing 47% (46 species); the herbaceous ones constitute 46% (45) and the arboreal ones comprise 7% (7). The highest number of taxa was recorded on semithorn shrubland (52) piedmont scrub (48), oak-pine forest (44), while the mezquite shrublands shelter the lowest number of species (23).

Classification and ordination of main plant communities along an altitudinal gradient in the arid and temperate climates of northeastern Mexico.

Quantitative data on the ecology of the main plant communities along an altitudinal gradient in northeastern Mexico were obtained with the aim of identifying the most important environmental variables that affect plant distribution and composition. The main threats to these communities were also investigated. Importance value index (IVi) of the 39 most important species and 16 environmental variables were recorded at 35 altitudinal gradients each spaced at intervals of at least 100-m altitude. Classification and ordination of vegetation showed six well-differentiated but overlapping plant communities: alpine meadow, cold conifer forest, mesic mixed forest, xeric scrub, Tamaulipan piedmont scrub, and halophytic grassland. Altitude, minimum and average temperatures, and organic matter content are the main variables affecting the plant distribution in northeastern Mexico. Urban growth, mechanized agriculture, and changes in land use are the main threats in the short and medium term to plant communities in this area. Climate change also seems to be having an impact at present or in the near future as shown by the presence of exotic shrubs from warmer areas in mesic and temperate areas inhabited by oak and oak-pine forest.

La Hormiga Argentina Linepithema humile: Primer Registro en Opuntia spp. para el Estado de San Luis Potosí, México

Resumen. Primer registro de Linepithema humile en el Estado de San Luis Potosí, México, asociada a Opuntia spp.

Interacción genotipo-ambiente de 135 líneas endogámicas recombinantes de sorgo para producción de biocombustibles

1Departamento de Fitomejoramiento. Universidad Autónoma Agraria Antonio Narro. Calzada Antonio Narro, Núm. 1923. Buenavista, Saltillo Coahuila, México. C. P. 25315. Tel. 01 844 4110295. (vzamvil@uaaan.mx), (matgenoma@gmail.com). 2Departamento de Botánica. Universidad Autónoma Agraria Antonio Narro. Tel. 01 844 4110252. (javq05@yahoo.com.mx). 3Departamento de Ciencia y Tecnología de Alimentos. Universidad Autónoma de Coahuila V. Carranza y González Lobo. Col. República. Saltillo, Coahuila, México. C. P. 25280. Tel. 01 844 4161238. (rrh961@hotmail.com), (cn_aguilar@yahoo.com.mx). §Autor para correspondencia: armando_roga@hotmail.com.