1. Qualität von Buchenvoranbauten (Fagus sylvatica L.) unterschiedlicher Flächengröße unter Fichtenschirm (Picea abies (L.) KARST.).
- Author
-
TIEBEL, KATHARINA, HUTH, FRANKA, and WAGNER, SVEN
- Abstract
Since the 1980s, single-layered conifer forests are being restored to natural mixed stands by introducing European beech (Fagus sylvatica L.) in keeping with the goal of sustainable forest management. Typically European beech are planted under a Norway spruce canopy maintain the option of high quality wood production. So far, the question of optimal aggregate area size with regard to the influence of edge effects on the quality development of European beech has not be addressed adequately. Therefore, in this study, the influence of edge effects on the quality of advanced-planted beech in clustered and clumped aggregates under a Norway spruce (Picea abies (L.) Karst) shelter was examined. The study areas were located in the Tharandt Forest (Free State of Saxony). In each of the 10 European beech clusters (ca. 10-15 m diameter) and -clumps (ca. 30-50 m diameter), the quality (Fig. 2) of selected European beech trees was assessed (Fig. 1). The age of European beech in the advanced plantings was between 16 and 20 years. At all study sites, plant densities (1.8/2 m x 0.7/0.8 m) and canopy cover conditions were comparable (Table 1). The results showed that European beech trees along the edge revealed larger branches (Fig. 6), shorter branch-free trunk sections (Fig. 5), and higher densities of live branches compared to trees within the aggregate centers. This effect was independent of aggregate size. However, after bringing together all quality parameters (Table 2), the edge effect was found to extend not more than 3 m into the aggregate areas (Fig. 7). This was confirmed in an assessment of the influence of the edge effect on the diameter of the largest dead and live branches using the linear mixed effects models (LMM) (Table 4). Along the 3 m edge strip towards the aggregate center, the quality and competition increased continually. Yet intraspecific competition was largely determined by plant spacing. A correlation between aggregate area size and intensity of competition pressure could not be proven (Fig. 4). Differences in quality development of European beech in cluster- and clump aggregates were not found (Fig. 3). Thus, it seems possible to produce potentially high quality timber of European beech in the center of clusters and clump aggregates. Although the edge effect was restricted to a small strip around the advanced planted beech aggregates regardless of aggregate area size, it would still seem more practical in forest management to establish larger aggregates with a higher probability of producing high quality wood. Furthermore stumps and canopy trees left in the aggregate centers lead to higher variation in the planting density, which means that the restriction in sidebranch development from neighboring trees decreases, thereby increasing growing space and light availability (Fig. 8). This results in a one-sided crown expansion and the development of larger branches. Therefore it is necessary to achieve homogeneous plant spacing in young European beech stands, and to attain appropriate Norway spruce canopy densities before establishing advanced planted European beech aggregates. [ABSTRACT FROM AUTHOR]
- Published
- 2016