A break-even technique based on the net present value is used to determine the stand characteristics of understocked pine and spruce stands profitable to grow. The Finnish Private Forests Act prohibits from leaving forest land idle after clear cutting, and so the problem of further growing of a understocked stand is similar to the optimal replacement of an old machine. Dynamic programming is applied to choose the best treatment alternatives for different initial stands. The break-even curves were strongly affected by the cost of capital (interest rate) but also by the tree species, the dominant heigt and the age of the stand, site type, and the value of future tree generations. The present Finnish norms concerning the urgent regeneration of understocked stands were found out to require from the point of business economics far too high growing stock if the growth potential of a stand is fair enough (15-60 percent of the mean annual growth of normally stocked thinned stands).
651 (Kalkulation des Aufwands (Kosten) und der Rentabilität (d.h. Kosten-Nutzen-Analyse)) 653 (Wertentwicklung des Einzelstammes und des Bestandes; Wertstruktur des Bestandes) 174.7 (Coniferae [Siehe Anhang D]) [480] (Finnland)
