Estimation of site class and average age in uneven-aged pine stands in Mexico.

This paper deals with an investigation about the estimation of site class and average age in uneven-aged pine stands in the Sierra Madre Oriental, Nuevo Leon, Mexico. For this study, 20 sample plots of 0.05 ha were established in a 16 ha large uneven-aged natural stand of Pinus teocate with different sites (site classes 1.5 to 11.5). The structure of the total stand and the stem populations of the sample plots are characterized by a mixture of homogeneous tree groups with different ages (Tab. 1). Within the individual sample plots, the sample trees of the different tree groups have almost the same site class, independent of age and dimension. In the 0.5 ha sample plots, the age of the predominant trees is considerably greater (up to 20 years) than the average age of the tree population. For this reason, to estimate the site class in these uneven-aged pine stands (both in the total stand and in the individual sample plots), you must use the mean age and the mean height of the relevant tree population.