Radial growth of pine species in stands subject to selection cutting in Santa María Lachixío, Oaxaca, Mexico

Introduction: The evaluation of the effect of management activities on trees is essential to gain a better understanding of the processes occurring in the stands.  Objective: To evaluate the effect of selection cutting on the growth of pine species in uneven-aged stands. Materials and methods: Thirty sampling sites were established in two mixed pine stands subjected to selection cutting in 2003. The stumps of this harvest were used as site centers and the growth of the residual trees was evaluated in a 10-m radius; tree-size variables and competition indices were calculated. Results and discussion: In the first five years after the harvest, 47 % of residual trees showed significant growth (P ≤ 0.05). Stump diameter, diameter at breast height and competition were the most important variables to explain growth. The competition area of the harvested individuals (stumps) showed influence up to a 15-m radius. The increase in basal area (IBA) was 71 % with respect to pre-harvest growth. This increase was related to the basal area sum of the residual trees and 1.3 m2 per site (41.3 m2·ha-1) was established as the threshold from which a release is nullified by residual competition.  Conclusion: Selection cutting influences residual tree growth in a differentiated way; the response may be positive, negative or nil depending on size and local competition.