Development of the Norway spruce (Picea abies /L./ Karst.) stand established by various spacings and affected by abiotic harmful factors and ungulate game

Abstract

The paper presents the results of 30-year research on silviculture-production relationships in a 50-years-old Norway spruce stand (a small-pole stage) originated from artificial regeneration in a mountain forest. The stand was established in four different spacing variants: (i) 1.5 × 1.0 m, (ii) 2.5 × 1.0 m, (iii) 2.5 × 1.5 m, and (iv) 2.5 × 2.5 m. At each spacing, three management methods were investigated: geometric (schematic) intervention, mixed selective intervention, and control (no intervention). The development of the stand was disturbed by repeated snow breaks, rime and ungulate game damage. As a result of these harmful factors, the number of trees has declined markedly, especially in the last decade. This was also confirmed by an insufficient number of target trees in all trial variants. The analysis of quantitative production showed different results in some parameters. We found the most favourable results for the mixed selective method of tending. The 2.5 × 1.5 m spacing with an initial number of 2 667 trees per hectare or the spacing with an even lower number of plants was found to be appropriate under the given conditions.