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Analysis and modeling of the structure and development of mixed forest stands in the Sudety mountains
Vacek, Zdeněk ; Remeš, Jiří (advisor) ; Hlásny, Tomáš (referee)
The thesis deals with analysis and modeling of the structure and development of selected mixed forests in protected areas of the Sudeten system, especially in the Giant Mountains national parks, Protected Landscape Area Broumovsko and Orlické Mountains, but also in other areas of the Czech Republic. This study is composed of a set of six published manuscripts that are covering three thematic ranges: structure of forest stands, regeneration of forest stands and forest modeling. The main objective of this work was to evaluate a vertical, horizontal and species structure, total diversity and development of mixed forest stands in central Sudetes. The partial aim was to analyse production parameters of forest stands, effect of microrelief and game on natural regeneration and assessment of dead wood in the area of interest. Further, the objective of the study was to develop explicit and non-explicit crown width and slenderness quotient models for Norway spruce (Picea abies L.) and European beech (Fagus sylvatica L.) and to predict the development of mixed forest ecosystem using growth simulations and to evaluate parameters and interactions among stand structure, climatic factors and natural regeneration, using especially analysis of variance, correlation matrix, spatial statistic and multivariate analysis. For this purpose a system of permanent research plots was used, which are regularly monitored since 1980 or were newly established. Using mapping technology FieldMap, selected parameters were measured for tree layer, natural regeneration individuals and dead wood. The results showed that the spatial distribution of beech stands in optimum stadium changes with the altitude from the regular pattern through random to aggregated spatial pattern of beech forests near the timberline. The spatial distribution of natural regeneration is highly aggregated, distribution of stumps is random and horizontal structure of the centroids of the crowns is always more regularly distributed than stems due to crown plasticity. Browsing damage of the leading shoot by game is an important limiting factor for height growth of natural regeneration, especially for silver fir (Abies alba Mill.), rowan (Sorbus aucuparia L.) and sycamore maple (Acer pseudoplatanus L.). The study of the influence of microrelief on the growth of beech regeneration showed that the highest average height was found on slope and pits, while the lowest on the mounds. From the effect of climatic factors on the radial growth of trees, it was found that temperature is a limiting factor for growth in mountain areas, respectively that positive effect of temperature decreases with decreasing altitude and conversely the influence of precipitation increases. Finally, spatially explicit models (as opposed to non-explicit) described a larger part of the crown width variations for spruce and beech and of the slenderness quotient for spruce. The largest contribution to the models after breast diameter was dominant height.
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