Our objectives were to recognize the composition of forest species, characterize their distribution and abundance, and identify the factors that determine their presence or absence in the area of Sierra Fria, Aguascalientes, Mexico. A sampling plan was elaborated using three criteria: altitude, relief and forest cover. Sixty samplings were realized in sites of 600 m2 and randomized in different solar expositions. The arboreal and brush species, the frequency, and ecological conditions that determine their presence or absence in site were identified. A Canonical Correspondence Analysis and Montecarlo’s test (a= 0.05) was conducted. We identified 50 species; three are new reports in the area. Quercus potosina was found and Juniperus deppeana is more widely distributed; the most abundant are J. deppeana, Q. potosina, and Pinus leiophylla. The greater ß diversity is in convex sites (ßw= 5.80) and sites with altitudes of 2400 and 2600 m (ßw = 7.22). The altitude, relief, the slope and solar exposition are variables more implicated in the distribution and abundance of the species (Montecarlo’s test, p = 0.0020). For this reason, the interventions of handling must consider the relation species-environment.
Key words: istribution and abundance, Sierra Fria, ß diversity, plant ecology and management.
