Structural and dynamic changes in mixed forests of beech and fir on Mt. Goč

Abstract

The primary goal of this research was to analyze the structural, production and dynamic changes of the forests of beech and fir in permanent sample plots of Mt. Goč, excluded from regular management for a period of 35 years (1977–2011). The established principles of spontaneous development and selfregulatory processes could have implications on the regular management in these forests located in the area of Mt. Goč and other areas.

The results of this research in the permanent sample plots indicate that the mixed forests of beech and fir have suffered a number of changes in terms of structure and production in the investigated period. Structural disruptions have been the result of a decrease in the share of small and medium-diameter trees, as well as an increase in the share of trees of large dimensions in the total number of trees. The curves of distribution have been moved to the right and in terms of shape they differ from the lines that are typical of selection forests. A relatively large number of trees per hectare and the described distribution by diameter classes have resulted in the high values of basal area and stand volume. In addition, a high volume increment has also been recorded. The quality and incremental capacity of the stands have been reduced due to a significant share of old beech and fir trees. The accumulation of volume slowed down the dynamics of stand development and hindered rejuvenation and recruitment, as the necessary prerequisites for structural stability and functionality in selection forests.

The observed trends of development in these forests in the sample plots clearly indicate that a structurally stable, socio-economically and ecologically valuable selection forest is possible to achieve only with an active and continuous implementation of a set of management procedures, which primarily refers to selection cutting. Self-regulatory processes that are allowed over time, as in the case of the analyzed sample plots, are increasingly distancing us from this goal.