RESPUESTA DE LA REGENERACIÓN NATURAL EN DOS SISTEMAS SILVÍCOLAS APLICADOS EN TLAXCO, TLAXCALA

Abstract

Regeneration cutting is among the most important silvicultura! treatments in forest management, and therefore it is important to assess their effects. In the region of Tlaxco, Tlaxcala, regeneration cuttings have been applied for more than twenty years but no studies on their effects are currently available for the forest areas with timber harvesting. The objective of this study was to evaluate natural regeneration under clear-cut and seed tree methods in the region-of Tlaxco in the state of Tlaxcala. Seedling density, frequency of regenerated sites and seedling vigor were assessed through a systematic sampling design with 1 O m2-circular plots; seedlings were classified in three height classes. Regeneration under seed­tree treatment varied from zero to 1, 636 conifer seedling/ha for height class C1 (from 0.30 m to 1.50 m), whereas for height classes C2 (from 1.51 to 2.75 m) and C3 (bigger than 2. 75 m) varied from zero to 1, 720 and 2, 840 seedling/ha respectively. For clear-cut these values varied from 500 to 1, 900 seedlings/ha for C1, 166 to 833 seedlings/ha for C2 and O to 166 seedlings/ha for C3. In areas with seed-trees, frequency of regenerated sites with conifers varied from zero to 90 per cent, with seedling vigor from poor to optimum; similar results were for clear-cut method. In general, seed-tree areas have not rached adequate conifer seedlings density, although the focus have regenerated, in contrast, clear-cut areas showed adequate seedling density for broad-leaves.