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Letokruhové analýzy mladého vrchovinného smrku ztepilého
Hanáček, Pavel
This bachelor thesis is focused on an tree rings analysis of young upland spruce. It was found out by the method of image analysis and it also include treatise how are tree rings influenced by climate. The samples were collected as stem discs from diameter breast height and samples were come from three different localities which are situated in Drahanská upland. These localities stand between 400 and 625 metres above sea level. Software WinDENDRO was used to measure tree rings widths. Then PAST 32 was used for crossdating, as well as these programs was used another called ASTAN and for result processing was nice to use the EXCEL 2013. The widths of tree rings are significantly correlated with precipitation and temperature of previous year in Rovná. In Habrůvka the widths of tree rings are significantly correlated with precipitation and temperature of current year. In the last one area in Habrůvka is seen that the width of tree rings are significantly positive correlated with precipitation of previous and current year, on the other hand temperature is not connected with any significant correlation.
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Růstová odezva dřevin středoevropského temperátního lesa na disturbanční událost =: The growth response of Central European temperate forest trees to disturbance events /
Vašíčková, Ivana
The growth response of trees to disturbance events in 8 beech-dominated natural forests in Czech Republic was studied using standard tree-ring analysis. With the use of circa 2 000 increment cores a disturbance regime of Žofín old-growth forest was reconstructed. The results indicate not only disturbance intensity, but also their spatial characteristics determine the effect of disturbance on further forest ecosystem development. As the picture of past disturbances had not emerged to be sufficient enough to describe a historical forest development, recognizing the statistical error of their reconstructions was of great importance. Thus, the following studies focused on quantification of uncertainty in detecting the disturbance history using dendrochronology. Uncertainty in determination of summary disturbance history within the whole stand as well as disturbance spatial patterns were evaluated. The results uncovered that the specific character of dendrochronological data, i.e. the different reactions of individual trees to the identical disturbance event, was a significant source of this uncertainty. The follow-up study logically concerned on examination the true response of Fagus sylvatica to disturbances, dated by independent dendrometric and photogrammetric datasets. On the basis of analysis of nearly 300 tree responses, new empirically-derived criteria for dendrochronological determination of tree growth response were suggested. Finally, factors controlling growth response of Fagus sylvatica to disturbance events were addressed. Regression analysis determined complex of diverse factors of different spatial levels driving the growth reaction following canopy opening.
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Environmental control over growth of coniferous trees with attention to Norway spruce
Kníř, Tomáš ; Čada, Vojtěch (advisor) ; Ulbrichová, Iva (referee)
Norway spruce belongs to the pine family. It has conical shape of the crown and straight trunk, the height ranges from 20 to 35 meters. Its natural habitat in the Czech Republic is in high elevations. The optimal temperature is 6 °C and the rainfall in the vegetation period is 490 580 mm.
The thesis also contains data about growth and the requirements for influential processes and regulators. I also review the formation of the growth rings - i.e. growth ring definition, formation and internal and external influences.
The thesis also focuses on dendrochronology. This science is a basis for obtaining information from dated growth rings. Using dendrochronology we can determin the annual diameter increment and the age of the tree. This science is divided into several different subdisciplines according to the usage of the growth rings data such as dendroclimatology, dendroecology, dendrogeomorphology, dendrohydrology and dendroarcheology. The selection of the area where samples are collected for the data analysis is the key factor.
The environment influences the growth of the trees both in the positive and the negative way. The climate is one of the most important factors that influence the growth. Climatic influences are mainly rainfall and air temperature where the influence differs between low and high altitudes. Anthropogenic influences, mainly air pollution (ozone, carbon dioxide, nitrogen, sulfur dioxide), play important part for the tree growth as well.
From the gained knowledge is clear that Norway spruce should be in the future planted in higher altitudes where in case of global warming better conditions are for the tree.
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Srovnání stavby a vybraných vlastností dřeva douglasky tisolisté z různých stanovišť
Timko, Lukáš
The aim of this thesis was to analyse the macroscopic structure of the wood of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and determine selected physical and mechanical properties with an emphasis on the comparison of juvenile and mature wood zones. Additionally, the structure and selected properties of the wood from sites varying in the forest types (3K, 3B, 3A) were compared. Five sample trees were sampled in each of the three selected sites. Their rootstock parts were then worked into test specimens with dimensions of 20 x 20 x 30 mm a 20 x 20 x 300 mm. The selected wood properties were the density at moisture content of 0% and 12%, basic density, the total shrinkage in all three basic directions, the total volumetric shrinkage, strength in compression parallel to the grain, bending strength, and the modulus of elasticity in bending. Additionally, a tree-ring analysis was conducted. It was found out that the juvenile wood has wider rings, a lower proportion of earlywood and all the observed properties showed lower values. The properties determined and the structure of the wood from the selected groups of forest types is statistically significantly different in most cases. From the forestry perspective, the resulting material characteristics of wood of Douglas fir are greatly dependent on the site; however, the precise location of the sample within the stem (centre or periphery) has a more pronounced effect on the properties.
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Optimalizace cílové tloušťky při nepasečném způsobu hospodaření na ŠLP ML Křtiny
Štěpán, Jan
This thesis deals with the optimization of the target thickness in the forest managed under systems involving coupes, when converting to a permanent forest (not managed under systems involving coupes) on ŠLP ML Křtiny. The optimization was focused on Scots pine, European beech, Oak sessile and Norway spruce tree species. The final optimal target thickness was established as the intersection of biometric and economic aspects for pine 45 cm (range 39-52 cm), for beech 50 cm (range 44-56 cm) and for spruce 52 cm (range 48-58 cm). In the case of oak in the natural conditions, the culmination of the thickness growth is not occurred. That could reach dimensions of trees, they need, in addition to the appropriate site conditions ensure appropriate production measures the optimal cenotic position, respectively a growth area. The average social area is for oak 26.22 m2, for pine 29.08 m2, for beech 25.26 m2 and for spruce 22.88 m2. The average available crown space is for oak 27.83 m2, for pine 26.59 m2, for beech 23.64 m2 and for spruce 19.38 m2. The average available stem space is around 74 m2 for oak, 84 m2 for pine, 71 m2 for beech and 66 m2 for spruce. Since it is an exact determination of the culmination of the thickness growth using growth ring analysis is time consuming, is better a simpler (operational) the landscaping solutions in adult stands, trip during which evaluates production potential habitats and species on the basis of the achievements of the individual dimensions of the strongest individuals in a selected population. This information is suitable ideally complement the statistical data from the operational inventory, and it must modify their best as the upper quartile breast height diameter of the wood.
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The wood plants in the mown meadow: the analysis of morphology, age, growth and surviving of woody plants on species-rich meadows in the White Carpathian. Bc. Thesis, in Czech.
MAZŮREK, Petr
This study deals with the presence of woody species in species-rich, savanna-like meadows (with scattered Quercus spp. trees) in National Nature Reserve of Čertoryje, Bílé Karpaty Mts., SE Czech Republic. The first part is a community-oriented study of variation of woody species composition on meadows with different land-use management (regularly mown, recultivated,abandoned etc.). Indirect ordination analysis (DCA) was used to relate woody species composition to land-use history (seven meadow types) and species composition of the surrounding vegetation. Further, attempts were made to explain the occurrence and survival of woody species by their life-history traits (root:shoot ratio, regeneration ability after mowing etc). The second part of the thesis tries to identify the most prominent climatic factors affecting the growth of two common oak species in Čertoryje (1) by establishing the mean relationships between tree ring residual chronology and climate through bootstrap moving correlation and response-function analysis, and (2) by distinguishing ``pointer years{\crqq}, which correspond to abrupt changes in growth pattern and reveal the tree-growth response to extreme climatic events, such as summer drought. Since the oaks are ring porous species with abrupt transition between earlywood and latewood, both parameters were measured and used to obtain subseasonal climatic information.
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