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Response of tree rings and NDVI of Central-European conifers to extreme climatic events
Mašek, Jiří ; Treml, Václav (advisor) ; Šilhán, Karel (referee) ; Piermattei, Alma (referee)
Terrestrial ecosystems, mainly forests are important sinks of atmospheric carbon with high year-to-year variability driven by moisture availability. Trees store carbon in various compartments of the biomass, namely in stems, roots, and leaves. In this doctoral thesis, I investigated climate-growth responses of stem biomass (represented by tree rings) and leaf biomass (represented by normalized difference vegetation index; NDVI) of Pinus sylvestris and Picea abies in temperate forests of Czechia. I was interested in (i) general climate-growth responses and specifically, in reactions to drought and (ii) topographical factors influencing these responses at various spatial scales. We demonstrated that climate-growth responses of both species' tree rings in the lowlands revealed a significant positive and negative influence of moisture and temperature, respectively, while in higher elevations the responses were opposite. At a landscape level, the topography of relief modulated responses of Pinus sylvestris tree rings, while at the large-scale level, the geographical position and elevation (temperature gradients) were the main factors for both species. Responses of NDVI were slightly weaker compared to tree rings and did not show the influence of topography at any scale probably because vegetation...
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The influence of climate on the radial growth of Scots pine in the northern Scandinavia
Tomeš, Miroslav ; Treml, Václav (advisor) ; Šefrna, Luděk (referee)
The presented master's thesis deals with the influence of climate on the radial growth of Scots pine in the northern Scandinavia. Trees growing at the polar treeline are sensitive to environmental changes, and therefore their wood is used to study growth responses to ongoing climate change. During the period of the 20th and the beginning of the 21st century, air temperatures and precipitation sums were correlated with tree rings and dendroanatomical data of Scots pine from northern Finland. It was found that the widths of the tree rings had a slightly increasing trend during the observed period. Within the framework of the correlation relations, the controlling influence of the air temperatures of the current July on annual increments was confirmed. Thanks to the higher temperatures of the summer season, wider tree rings were formed. In addition, May and summer precipitation have been shown to be important for the final width of the tree ring. The currently often discussed problem of decoupling the tree ring chronology curve from rising summer temperatures ("divergence problem") was not clearly observed in this work. In order to evaluate the dendroanatomical parameters, the tree rings of the studied individual were divided into four sectors with a similar number of cells in the radial file. During...
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Zhodnocení výskytu a růstu jmelí bílého (Viscum album) na vybrané lokalitě
Halfar, Jan
European mistletoe (Viscum album L.) is an evergreen semi-parasitic plant, with a wide host range of both deciduous and coniferous trees. As a native species, this plant is widespread throughout Europe. The first part of this paper is aimed as a literature review, which includes a description of European mistletoe, a general description of its occurrence and its effect on host woody plants. The second part focuses on a survey of a selected area between the villages of Bělá and Chuchelná (Opava district), where the degree of infestation of individual trees, the species of infested trees and their age are assessed. At the same time, the number of mistletoe plants, their distribution in the crown, and in the oldest mistletoe specimens their age and haustorium length were determined at three sites in the forest area belonging to the Lesy města Brno a.s. In this work it was found that mistletoe occurred mainly on Scots pine at site 1, but was also found on silver fir and small-leaved linden. At site 1, mistletoe began to invade pine after the age of 30. Mistletoe in young stands grew mainly on trees with the greatest high growth and in the upper part of the crown. On the basis of these results, I recommend to concentrate the management of mistletoe-infested forest stands on tree age above 30 years during planned thinning and to actively remove infested individuals from the stand. Changing the species composition of forest stands in favour of mistletoe-resistant species is also one of the ways to prevent the spread of mistletoe in threatened areas. At site 2, the age of the largest mistletoe shrubs ranged from 9 to 18 years. The longest measured haustorium was 18 cm in length and was measured on mistletoe at 17 years of age. From the measurement results, a relationship between mistletoe age and haustorium length was found. Knowing the haustorium length is important in the context of tree protection when performing branch pruning. Therefore, based on the results of this work, I recommend removing infested branches at a minimum distance of 30 cm from the mistletoe shrub, especially for older mistletoes.
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Assessment of drought response in local Scots pine ecotypes using anatomical, biochemical, and fluorescence stress markers.
Štěpánová, Kristýna ; Lhotáková, Zuzana (advisor) ; Stejskal, Jan (referee)
Global climate change and associated global warming is already a problem for temperate forest ecosystems and will continue to exacerbate the problem in the coming decades. Many species will have to adapt to a multifactorial combination of stresses, with increases in average air temperature, frequency and intensity of precipitation increasing drought episodes and drought-affected areas will enlarge. It is necessary to find ways to help the landscape cope with these intensifying phenomena. The possibility of planting suitable tree species that can manage water efficiently and survive even in periods of intense water scarcity is an option. The drought tolerance of trees is related to their phenotypic plasticity and ecotypic differentiation. Scots pine (Pinus sylvestris L.) is characterised by modest ecological demands on the environment and climate of the habitat, is phenotypically plastic and relatively drought resistant. The objectives of this study were 1) to evaluate and compare the response of different Scots pine ecotypes to drought stress due to reduced water availability using anatomical, biochemical, and fluorescence indicators of physiological status, and 2) to determine the biochemical phenotype of selected genotypes within a local Scots pine ecotype in a seed orchard in terms of...
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Scots pine climate-growth response in the topographically complex landscape of the Kokořínsko region
Fišer, Petr ; Treml, Václav (advisor) ; Šefrna, Luděk (referee)
The extensive Scots pine Pinus sylvestris forests in topographically complex landscape of the Kokořínsko region in the Czech Republic are a suitable area for investigating how trees react differently to climate factors depending on local site conditions. Individual habitats are characterized by specific conditions which can influence a wide range of growth factors. It is therefore important to understand these differences also from the point of view of ongoing climate change, which threats forest ecosystems in central Europe. The relatively dry environment of the highly permeable sandstone landscape is vulnerable to increasing drought, which will increase the stress of local Scots pine population. Samples from 20 sites divided into 4 categories of northern slopes, southern slopes, plateaus and valley bottoms are supposed to sufficiently represent variability of the local terrain. Correlation of tree-ring chronologies with climate variables as well as PCA analysis revealed that the greatest differences are between plateaus and valley bottoms. In case of highly exposed plateaus, drought seems to be the most important limiting factor, whereas at the valley bottoms temperatures at the turn of winter and spring are the main controlling factor. Signifficant differences between northern and southern...
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Geographical characteristics of extreme growth depressions of Scots pine in Central Europe
Mík, Milan ; Treml, Václav (advisor) ; Rybníček, Michal (referee)
The presented diploma thesis studies extreme growth depressions of Scots pine (Pinus sylvestris L.) in Central Europe. Examination of significant growth anomalies (pointer year analysis) is one of the methods, which investigates the reactions of forest stands to the ongoing climate change. Dendrochronological data was obtained from Czechia (23 sites) and Slovakia (4 sites). The main hypotheses of the thesis states that the extreme growth depressions relate to climatic anomalies, hence they can be explained geographically. The objectives were to 1) create a Cropper values chronology for each site which describes growth extreme depressions; 2) explain climatic causes of negative Cropper values for each site; 3) define geographical predispositions of a spatial distribution of extreme growth depressions; 4) spatially interpolate extreme growth depressions. The calculation of Cropper values was based on a normalisation in a moving window method with a 13-year window size and the input data detrended by a 50-year cubic smoothing spline. Created chronologies were correlated with monthly climate data (temperatures, precipitation, SPEI). Geographical predispositions of the spatial distribution of growth depressions were calculated using a hierarchical cluster analysis. The cluster analysis was also applied...
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Vývoj epigeické arachnoentomofauny borových porostů v požářišti revíru Bzenec - Moravská Sahara (LS Strážnice)
Prágr, Jakub
Successional changes occurring in the structure and composition of communities of epigeic fauna in the first three (Coleoptera: Carabidae), or two (Araneae) years after the pine stands fire have been studied since 2013 in the territory of the Moravian Sahara (Bzenec, Czech Republic). 11 permanent research plots were established in order to evaluate the response of epigeic fauna and habitat changes after the fire. These included areas deforested after the fire, pine stands severely affected by the fire (27 years) left to natural successional development and pine stands (94 years) with ongoing salvage cutting. Qualitatively equal stands undisturbed by the fire (29 and 78 years) were simultaneously studied. Pitfall traps were used (5 pcs/area) to determine the state of the epigeic fauna. A total of 90 kinds of Carabid species and 151 spider species were caught and determined. The structure and composition of ground beetle and spider communities in locations disturbed and undisturbed by fire differed throughout the observation period. Ground beetle and spider communities of biotopes undisturbed by the fire showed a stable structure and community composition, while in pine stands disturbed by the fire, a gradual increase in species dominance and diversity of heliophilous and xerophilous groups took place. A significant decline in the species diversity of spiders in pine stands disturbed by fire was recorded between 2013 and 2014. Ground beetle communities showed the opposite trend. Ground beetle and spider communities in the surveyed area demonstrated a sensitive link to a change in the microclimatic conditions of the studied habitats; on the basis of changes in their composition, it was therefore possible to infer changes taking place also in the stands, where the effects of fire were not apparent at first glance.
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Růst kultur založených rozdílnými biotechnikami sadby krytokořenného sadebního materiálu
Novák, Jiří
The aim was to determine the effect has different Biotechnics of the seed shattering container-grown planting material of Norway spruce, European beech, Durmast and Forest pine. Planting and measurements were carried out on two plots in the forest management unit Chotěnov village. Soils on the observed surfaces are of different nature - clay and sandy loam. For planting material spruce beech was chosen five kinds of seed. For planting material oak to pine three species. On the basis of the measured values was found, which way is best suited for planting, which is the least. It was determined on the basis of graphical and tabular outputs. The overall assessment then accounted for the weight tests, which compared the planting of seed. The outcome of the work was the assessment of the growing planting materials of different biotechnique seeds.
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Vliv biotechniky sadby na odrůstání krytokořenného sadebního materiálu
Nedomanský, Daniel
The aim of this study was to determine the effect of different plantation biotechnics on growth of Scots pine and pedunculate oak containerized planting stock. Both types of planting stock were grown to the same technology type used plantpot QUICK POT D 60 T/12 and 15. Monitoring was carried out by two research areas that have different soil conditions. It was a sandy soil and ground water affected. These areas were located in the Hradec Králové region. We tested following plantation biotechnics: hole planting, planting spade, planting fork, planting thorn and planting stick. It was also monitored overlaps the root ball of a layer of mineral soil. The evaluation was carried out by one growing season after planting. Plant mortality, parameters of above-ground plants part, damage of biotic and abiotic factors, plants vitality and especially root system were monitored. Based on the evaluation of these observations and measurements it has been found which plantation biotechnics are appropriate or not unsuitable for the growing of planting stocks, depending on site soil conditions. The outcome of this work is an overall assessment of individual planting biotechnics and recommendations that the most suitable planting biotechnics for reforestation from above-mentioned planting stock is planting hole.
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Srovnání stavby a vybraných vlastností sibiřského modřínu a borovice lesní
Kopecký, Petr
The aim of this bachelor thesis was to compare the macroscopic and microscopic structure and some mechanical and physical properties of the wood of Scots pine (Pinus sylvestris L.) and Siberian larch (Larix sibirica Ledeb.). The wood was used to make samples with dimensions of 20×20×30 mm and they were used for the measurements of individual properties. The properties selected for establishment were density at a moisture content of 0% and 12%, the average tree-ring width, the average latewood width and percentage, the fibre saturation point, the maximum moisture, total swelling in all three basic directions and the total volumetric swelling, the swelling coefficient, and the compression strength parallel to the grain as well as the modulus of elasticity.
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