Resumo

GUERRA DE LA CRUZ, Vidal et al. Forestry structure of populations of Pseudotsuga menziesii (Mirb.) Franco in the states of Tlaxcala and Puebla. Rev. mex. de cienc. forestales [online]. 2012, vol.3, n.13, pp.73-86. ISSN 2007-1132.

Pseudotsuga menziesii populations in central Mexico are small, fragmented and affected by natural and anthropogenic factors. Little is known about the stand structure of these populations, which limits development of management programs despite the protected status of the species. The objective of this study was to characterize and to compare the stand structure of Pseudotsuga forest in seven locations in the states of Tlaxcala and Puebla. A systematic sampling with circular nestled plots of 0.1, 0.05 y 0.005 ha were used to register stand attributes including diameter at breast height (DBH) of alive, death and stumps of all tree species. Results in basal area and Value of Importance Index showed that all locations are dominated by an association of Pseudotsuga-Quercus sp., and to a less extent by other conifer species. Diameter distribution of Pseudotsuga are non-regular and unbalanced, lacking small (<10 cm) and large (>85 cm) diameter classes. Stands in Tlaxcala showed higher densities of standing death trees and stumps than those of Puebla. A modified Morista's Index of Similitude suggested the influence of geographic proximity of populations as well as the disturb factors, in shaping observed diameter distributions.

Palavras-chave : Central Mexico; diameter mensuration distributions; disturb factors; similarity index; mortality rate; Pseudotsuga menziesii (Mirb.) Franco.

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