Resumo

SAENZ-ROMERO, Cuauhtémoc et al. Altitudinal morphological variation among Pinus devoniana Lindl. Populations and putative variety cornuta in state of Michoacan. Rev. mex. de cienc. forestales [online]. 2012, vol.3, n.13, pp.19-28. ISSN 2007-1132.

Understanding the patterns of morphological variation along environmental gradients is useful to distinguish taxonomical entities and take management decisions. Morphological variation of cones, seeds, fascicles and buds were analyzed on individuals from 16 natural Pinus devoniana (ex P. michoacana) populations collected along an altitudinal transect (from 1,600 to 2,450 m, one population every 50 m of altitudinal difference) near Morelia city, in the state of Michoacán (Mexico). Univariate (ANOVA) and multivariate (principal components and cluster) statistical analyses were conducted, in order to clarify if putative varieties exist. There is a significant pattern of morphological altitudinal variation, where populations from lower altitudes have larger cones, needles and seeds than populations from middle and higher altitudes. The multivariate analysis discriminated individuals and populations in two clearly distinctive groups: one group made of individuals from populations originated between 1,600 m to 1,850 m of altitude, which would correspond to Pinus devoniana var. devoniana (equivalent to P. michoacana typical); a second group is composed of individuals from populations originated between 1,950 m to 2,450 m, which would correspond to Pinus devoniana var. cornuta (ex P. michoacana var. cornuta). Thus, we suggest the separation of P. devoniana in at least two varieties: P. devoniana var. devoniana and P. devoniana var. cornuta.

Palavras-chave : Altitudinal variation; cluster analysis; morphological variation; Pinus devoniana Lindl.; Pinus michoacana Martínez var. cornuta Martínez; principal components.