Abstract

GUTIERREZ VAZQUEZ, Benito N. et al. Selection of outstanding mahogany (Swietenia macrophylla King.) trees in a natural stand based on multivariate methods. Rev. mex. de cienc. forestales [online]. 2016, vol.7, n.37, pp.51-63. ISSN 2007-1132.

A methodology to select phenotypically outstanding trees in a natural stand of tropical species based on multivariate methods using the technique of principal components analysis (PCA) and with support of the software System Visualization Stand (SVS) is described here. This study was conducted on a natural stand of mahogany (Swietenia macrophylla) of 50 ha, located in a semiervergreen forest. A base population of 427 mahogany trees with a normal diameter higher than 7.5 cm was defined. The method of PCA was used with data of eight variables of stem, cup and buttress. The variables stem normal diameter, total height and crown diameter, were the ones that better identified the characteristic phenotype of the selected trees in the first component, explaining 79.4 % of the total variance. The application of SVS allowed the spatial analysis of possible scenarios and the selection of 30 plus trees, when setting down as restriction a minimum distance of 70 m between selected trees. The selection differential for the characteristics of economic interest gave positive values. The normal diameter had a higher selection differential (84 %) than that of the crown diameter with 61 %. The PCA-based method proved to be effective since the plus trees selected by it were the best in the field. These results allow recommending the PCA method for selecting superior trees in a natural stand of tropical species, where conditions limit the use of classic methods of selection such as the comparative one.

Keywords : Principal components analysis; plus tree; phenotype characteristics; selection differential; genetic gain; Swietenia macrophyla King.