Influencia de la competencia en el crecimiento diamétrico de Pinus durangensis Martínez en Durango, México

In this paper the effect of competition on individual tree diameter growth of Pinus durangensis was analyzed. Trees were growing in mixed and uneven-aged stands in Durango, Mexico. The data used in the study were obtained from two forest inventories performed in 2009 and 2014 in 16 permanent sampling plots for forest and soil research (SPIFyS) of 2 500 m2 in size. Pinus durangensis was the dominant species within the sites, covering 39.44 % of the importance value, and it is growing with other 18 tree species. 14 distance-independent and 11 distance-dependent competition indices were used to evaluate the effect of competition. 11 competitor selection methods were tested in combination with the selected distance-dependent indices. Distance-independent competition indices showed slightly better results than distance-dependent indices for predicting diameter at breast height growth for the studied tree species. The distance-independent competition index derived from the ratio between of the basal area of the reference tree and the basal area per hectare best described the effect of the competition, and therefore, it is recommended for its possible addition within further models to predict the breast height diameter growth for the tree species analyzed in this study.