Abstract

Our approach to thinning has changed over the last 50 years: why? (Essay) Thinning methods and principles have always fluctuated between an approach based on moderate interventions, aimed at maintaining a sufficient stocking level (the so-called “volume effect”) and the liberation of crowns of a limited number of trees. Nowadays Schädelin's concept of selective thinning focused on trees with high potential for the future, based on the efficient removal of those competitors which cause the most interference, is widely accepted. However, as regards the intensity and strength of thinning there are different suggestions in terms of number of trees to be removed and the extent of liberation of the crowns. Moreover, there is no consensus on the transition between the phase of compression in the young stand and the first thinnings, nor on the optimal final stand density to be aimed at. After the dramatic fall in income from forests, it was necessary to revisit the principles of tending young stands, as the costs were excessively high especially because of the high number of trees. It now appears more efficient to use the natural, and free, processes of social differentiation. Interventions founded on the so-called biological rationalisation make possible a significant reduction in costs. The results of the economic analysis of the various thinning regimes, measured by the net average increment in value, net of harvesting costs, show clearly the advantage of the volume effect and of maintaining sufficient stand density. However, it is also necessary to bear in mind stand stability, especially towards the end of the rotation period. Stand stability makes it possible to keep open, in both space and time, options for natural regeneration, which corresponds best to our goals of a multifunctional silviculture in the most efficient fashion.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call