Effect of scarification on soil change and establishment of and artificial forest regeneration under Nothofagus spp. in Southern Chile

Abstract

Soil scarification has been used as a silvicultural method to facilitate the regeneration of some forests, but it may have a negative impact on the properties of the soil. We evaluated the effect of a mechanized scarification on a volcanic soil after a shelterwood cutting in a Nothofagus spp. forest, located in the Andean region of southern Chile (39° 54 'S, 71° 56' 5 W, 970 m asl). A plantation of Nothofagus nervosa was established after scarification, and its physical (moisture content, bulk density, penetration resistance) and chemical (pH, organic matter, macro and microelements; saturation Al) soil properties were analyzed in scarified gaps and undisturbed forest. The size of N. nervosa planted trees was measured eleven months after their establishment (June 2010). The volumetric water content of the soil was similar with and without scarification (30-50%), regardless of the time of year. The bulk density was higher in the scarified soil when compared to the undisturbed forest. The soil nutrient supply in the gaps (0-20 cm) decreased when compared to the undisturbed forest (0-10 cm), but showed little difference between gaps and between locations within them. The N. nervosa plantation developed properly, with similar growth in gaps of different size. Scarification decreased soil quality; the effects on regeneration will need further evaluation throughout a longer period.

A Disturbance Ecology Perspective on Silvicultural Site Preparation

“…Silvicultural site preparation techniques have the potential to significantly affect nutrient dynamics [37,38], either positively or negatively. For example, the mixing technique may risk releasing too much of the nutrient reserves of a site in the first few years after treatment, resulting in the long-term depletion of nutrients.…”