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Sukcese vegetačního krytu po velkoplošném rozpadu horských smrčin v NP Šumava
Pokorná, Pavlína
The aim of this thesis is to evaluat the present state of herb layer vegetation after disturbance of mountanin Norway spruce forests in the Šumava National Park and wheather the herb layer vegetation of the mountain Norway spruce forest is determined by a spatial structure of general level of the upper canopy before disturbance even after twenty years. Overall, seven areas around Březník were evaluated. Releves of various one square meter areas which were situated under dead standing trees, under former subdominant trees, and in canopy gaps was conducted. Overall 242 phytocenological releves were made. The evaluation was supplemented by a tentative research of soil conditions with 22 soil samples taken. The results of phytocenological releves indicate that there is a connection between herb layer vegetation and its habitat of former canopy gaps, and a habitat of dead standing tree, which had formed the general level of the upper canopy in the past. However, the difference 20 years after the disturbance is not very significant, but it is still noticeable. It was discover that Avenella flexuosa and Vaccinium myrtillus are located in plots under dead standing tree and subdominant tree spruce compared to Luzula sylvatica which mostly appears in canopy gaps. The results also demonstrate, that the structure of herb-layer vegetation is conditional on habitat circumstances, particulary on the presence of rocks at the location. In areas where coverage of rock is higher Vaccinium myrtillus prevails and there is higher coverage of Norway spruce (Picea abies).
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Půdní prostředí v kotlíkové obnově lesa: charakter vodního režimu a formy minerálního dusíku
Petříček, Jan
This master thesis is a part of solved project called Natural regeneration dynamic under ecological conditions of gaps on example of School Enterprise Křtiny. In territory Habrůvka, forest district Borky, were created gaps in following forest stand types: beech (BK), mixed (MIX) and spruce (SM). Measurement took place on area of size 0,04 ha called small (S) and large (B) with size 0,1 ha. With concentration on locations: centre (C), mature stand (P), border east (T/E) and border west (T/W). It was measured moisture in all big gap locations (B). Continuous measurement was under way during all the year. From the obtained data was evaluated soil moisture and then compared with soil hydrolimits: wilting point (BV), point of decreased availability (BSD), point of decreased availability of water (LB) and capillary maximum capacity (MKK). Altogether, it was found that location centre (C) contains the highest soil moisture value. This thesis is focused on evaluation of NO3 -, NH4 +, C/N, Cox and mineral nitrogen. It was found out that spruce forest stand type (SM) has the highest concentration of NO3 -, NH4 +, C/N, Cox and mineral nitrogen. On the contrast, it has the lowest C/N ratio. Forest stand type beech (BK) had the lowest NO3 - value, C/N ratio and Cox. When evaluating of location, it was found that mixed forest type (MIX) and beech forest type (BK) are observed values higher on location centre (C). Spruce forest stand type (SM) had no as accurate values as those previous ones. In comparison between the big gap (B) and the small gap (S), there was found lower C/N ratio in the small gaps (S). Cox values were balanced. Mineral nitrogen showed higher values in beech big forest stand type (BK/B) and mixed big forest stand type (MIX/B). On the contrary, spruce forest stand type (SM) had higher values in the small gaps. Evaluation of NO3 - showed that the lowest values were in the beech big forest stand type (BK/B) with a significant difference toward to the spruce big forest stand type (SM/B). By comparing of size and location on a gap, there was found a higher concentration of mineral nitrogen, Cox and NH4 + in all the centers (C) of big gab (B). Total result values were often higher in centre (C). In NO3 - evaluation in the spruce forest stand type (SM) there were found higher values in the mature stand (P) in implementation of both small gap (S) and big gap (B). The data obtained are often very similar and thus can not be clearly and easily evaluated.
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Potenciál a limity přirozené obnovy smrku ve smíšených porostech na ŠLP Křtiny
Převor, Josef
The main aim of this work was to investigate the influence of relative diffuse radiation on the natural regeneration of a Norway spruce (Picea abies). There were chosen four research areason ŠLP Křtiny including the regeneration of the spruce in stand gaps with similar natural proportions (HS 441; SLT 3S, 4S, 4H; altitude 475-530 m n. m.). There were marked out four squared networks (5x5, resp. 10x10 m) where some features of spruce regeneration (density, height and the last height increase), herbs cover and relative diffuse radiation (ISF) were measured. The finding is that spruce seedlings sporadically appear at already 1-3% ISF. The highest density of spruce regeneration is around 18% ISF and the optimal increase (Ih > 10 cm) were over 27 % ISF. As far as density is concerned, south-eastern edge was found to be the most favourable. It is suggested to continue with border cutting with forward ameliorating and stabilizing tree species.
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