Influence of the seed tree method on the diversity of regeneration in a mixed forest in Durango, Mexico

Abstract

Introduction: Forest managers need to know the impact of regeneration cuts on tree species diversity in order to conserve it. Objective. To evaluate changes in tree species richness and diversity after applying the seed tree method in six communities. Materials and methods. The communities of Ciénega Grande, Las Ciénegas, La Colmena, El Venado, Los Bajíos and Pino Gordo of the Pueblo Nuevo ejido, Durango, were divided into three plots called: a) regeneration in seed trees cuttings (RST); b) regeneration in adult trees (RAT); and c) adult trees (AT). Starting from the center of each RST plot, and following the cardinal and subcardinal points, eight sites of 25 m2 and 0.1 ha were located to record the regeneration and adult tree species, respectively. Species richness indicators (Shannon-Wiener, Simpson, Pielou and Sørensen) were estimated to characterize the plots by community and were compared with t-tests and rarefaction analysis. Results and Discussion. Twelve species were recorded in the study area, of which 11 are found as a renewal of seed trees. Species richness in the RST plots with respect to that of AT was equal in the Ciénega Grande, El Venado and La Colmena communities, and higher in Las Ciénegas and Los Bajíos. The Shannon-Wiener and Simpson indices were higher in Pino Gordo, Los Bajíos and El Venado. The Sørensen index ranges from 0.67 to 1.0, indicating high species similarity among plots. Conclusions. The seed tree method in a mixed forest ensures the continuity of tree species diversity.