Spatial pattern of relict beech (Fagus sylvatica L.) forests in the Sudetes of the Czech Republic and Poland

Abstract

Horizontal structure of forest stands largely affects the competitive relationships between tree individuals and plays a significant role in the stand dynamics. The present study describes horizontal structure on nine permanent research plots (0.24-0.25 ha) in the regeneration and tree layer of autochthonous European beech (Fagus sylvatica Linnaeus) stands in the wide altitudinal gradient in protected areas in the Czech Republic and Poland. The spatial structure was classified in productive herb-rich beech sites, through acidophilic beech sites, exposed sites, to beech fragments near the timberline. The spatial pattern of tree layer was regular in the lowest parts of the altitudinal gradient of beech, random in the middle parts and aggregated in the beech forests under the hilltop phenomenon and extreme edaphic site. Nevertheless, trees in lower tree layers showed a tendency to the aggregated pattern, similarly like the strong aggregation of natural regeneration. In most cases, the parent stand had a significant negative effect on natural regeneration at a smaller distance (to 0.8-4.2 m). The spatial pattern of dead wood was mostly random. Because of the great plasticity of beech crowns, crown centroids were more regularly distributed than tree stems. The average displacement of crown centroids from the stem base was 1.5 m with the prevailing direction of 52.7% down the slope. Projected canopy cover was on average 10.7% higher compared to the canopy simulated by circular crowns.

Dynamics and structure of mountain autochthonous spruce-beech forests: impact of hilltop phenomenon, air pollutants and climate

“…On PRP with more favourable climatic and habitat conditions the parent stand had a significant negative effect on the spatial pattern of regeneration at a smaller distance (from stem base to 0.6-6.1 m), but on PRP under the strong hilltop phenomenon trees had a positive effect to 2.1 m due to a better microsite under the protection of the tree layer . Similarly, a negative effect of parent trees on the distribution of recruits was confirmed at a distance from stem base to 1-2.5 m in autochthonous herb-rich beech forests in the Broumovsko Hills (Bulušek et al, 2016).…”

“…Like in the Krkonoše Mts., this study of autochthonous stands also confirmed the positive influence of habitat extremes (altitude) on the aggregated spatial pattern of the overstorey (cf. Vacek et al, 2015b;Bulušek et al, 2016), but a small difference in altitude in our study and possible influences of past silvicultural management must be considered (Štefančík, 2015). This spatial model was revealed in other European natural forests with dominant beech (von Oheimb et al, 2005;Commarmot et al, 2005).…”

“…(Kučera, 1997;Holtmeier, 2003). This phenomenon causes reduced growth of trees, lower stand stocking, aggregated spatial pattern of the tree layer and lower canopy cover compared to forests at lower altitudes and in valleys (Bulušek et al, 2016).…”

Long-term transformation of submontane spruce-beech forests in the Jizerské hory Mts.: dynamics of natural regeneration

“…(Bulušek et al 2016;Králíček et al 2017). On the other hand, in those studies a positive relationship of recruits and tree layer in beech was confirmed on plots with extreme site conditions due to natural layering.…”

Structure and dynamics of spruce-beech-fir forests in Nature Reserves of the Orlické hory Mts. in relation to ungulate game

“…Natural regeneration was strongly aggregated, especially on unfenced plots due to lower number of recruits, that it corresponds with other researches from Sudetes Mts. (Vacek et al 2014b;Bulušek et al 2016). …”