Abstract

HERNANDEZ-DIAZ, José Ciro et al. Regular and irregular forest management evaluation of the Sierra Madre Occidental forests. Madera bosques [online]. 2008, vol.14, n.3, pp.25-41. ISSN 2448-7597.

The recovery of standing Pinus stock after a harvest in forests treated under irregular and regular forest management systems was evaluated. The management history of five forest properties managed under the Mexican Management Method of Irregular Forests (MMOBI) and twelve under the Silvicultural Development Method (MDS) during the period 1995-96 was analyzed. In addition, in 2004 within these forest properties, 12 basic MMOBI forest management units and 34 basic MDS units were sampled with an intensity of 5 % of their total area, using 1000 m² circular plots. Of the 17 properties managed, either with MMOBI or MDS in 1995-96, 11 had shifted to another forest planning method by the year 2004. In eight of the 17 properties, management programs for the harvest cycle following the one containing the data for the period 199596 indicated that there were modifications to the delimitation of the basic forest management units. It was found out that by 2004, even though a cutting cycle had almost culminated, the volume per hectare in six of the 12 MMOBI units analyzed and in 19 of the 34 MDS units analyzed were significantly different (α = 5%). The differences are attributed to the changes in delimitation of the basic forest management units and to a low precision of the forest inventories, due to: a) inadequate sampling intensity, b) errors in the estimation of diameters and heights classes, and c) the use of inadequate basal area factors.

Keywords : Basal area factor; stands delimitation; regular and irregular forest management; MMOBI; MDS.