Density management guide for natural stands of Pinus rudis Endl. in Oaxaca

Abstract

Forest density associated with site quality determines forest productivity and its measurement allows prediction of growth and mortality rates. Management through thinning improves forest characteristics by reducing competition between trees. The aim of the present study was to construct a density guide for the management of natural stands of Pinus rudis, in the Mixteca region of Oaxaca, Mexico. The Reineke's Stand Density Index (SDI) was estimated from the quadratic diameters and number of trees per hectare of 81 variable size sampling sites, located in pure forest, with full occupation and different development stages of forest stands. The Crown Competition Factor (CCF) was estimated by fitting the simple linear regression model with normal diameter-crown diameter data from 54 healthy trees, without physical-mechanical defects and that grown without competition. The adjustment of the Reineke model and that of simple linear regression was carried out using the ordinary least squares technique. The density guide was developed through SDI and CCF, these measurements allowed to know that the stands under study have density levels higher than 90 % of the SDI, with a quadratic diameter of 15 cm.