National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
Seasonal dynamics of physiological parameters of Norway spruce needles in mountain forest in relation to water balance of the forest site
Bednář, Pavel ; Albrechtová, Jana (advisor) ; Gebauer, Roman (referee)
Norway spruce (Picea abies (L.) Karst.) is an important economic tree species in the Czech Republic, which is currently significantly weakened and dying under the impacts of climate change. In young spruce forest stand in mountain region that was artificially established after the large-scale disturbance of forests in the mid-1990s, on the "U Dvou louček" research plot represented by a small forest catchment of an area of 32.6 ha, located in the upper part of the Orlické Mountains at an altitude of 880 - 920 m a.s.l., and in site conditions of predominantly Abieti-fageta piceae - water balance measurements were carried out during the 2019 and 2020 growing seasons. At the same time, during the mentioned two years, in total 6 samplings of biological material were carried out according to a standardized sampling methodology, and laboratory analyzes were carried out on this material. Laboratory analyzes were focused on three established age categories of needles, namely 1, 2, and 4 or more years old. The biophysical parameters of needles were determined based on the measurement of structural parameters and concentrations of photosynthetic pigments - chlorophyll a, chlorophyll b and total carotenoids from samples extracted in DMF using a laboratory spectrophotometer. Optical properties of the needles...
Study of common bean drought response with the use of leaf optical properties
Svitáková, Lenka ; Lhotáková, Zuzana (advisor) ; Zámečník, Jiří (referee)
The negative effects of climate change have affected the conditions of agriculture areas, which leads to hampered cultivation of crops, including the common bean's cultivation. Changes, such as extreme temperature swings and lowered water availability in soil create a big challenge for today's agriculture in seeking solutions for safeguarding the food security for all people on our planet. The aim of this thesis was to study a wider range of genotypes of common bean to quantify their resistance against lowered water availability in soil, and to establish new approaches for detecting drought stress with the use of leaf optical properties. From the methodological point of view, this thesis connects the leaf optical properties with anatomical and biophysical leaf traits. The common bean (Phaseolus vulgaris) and the tepary bean (Phaseolus acutifolius) were employed as the model organisms. Plants were cultivated in two differing environments - in a greenhouse setting at the Faculty of Science of the Charles University in Prague and on the experimental fields in Colombia at the international research institute for tropical agriculture - Alliance of Biodiversity International and CIAT. There were 48 genotypes included into the field experiments in Colombia. These included genotypes from both Mesoamerican...
Laboratory/Field Spectroscopy and Remote Sensing Image Data for Vegetation Studies
Červená, Lucie ; Kupková, Lucie (advisor) ; Pavelka, Karel (referee) ; Müllerová, Jana (referee)
Dominant vegetation species of two structurally and functionally different montane ecosystems were studied by means of laboratory and field spectroscopy and remote sensing image data: (1) a homogeneous human-influenced evergreen coniferous forest represented by a Norway spruce forest in the Krušné hory Mountains and (2) a heterogeneous natural ecosystem of a relict arctic-alpine tundra in the Krkonoše Mountains with predominance of grasses. The first part dealing with the Norway spruce forest is especially focused on the methods of laboratory spectroscopy. The assessment of Norway spruce stands on a regional and a global scales requires detailed knowledge of their spectral properties at the level of needles and shoots in the beginning, but ground research is very time-demanding. Open spectral libraries could help to get more ground-truth data for subsequent analysis of tree species in forests ecosystems. However, the problem may arise with the comparability of spectra taken by different devices. The present thesis focuses on a comparability of spectra measured by a field spectroradiometer coupled with plant contact probe and/or two integrating spheres (Paper 3) and proves the significant differences in spruce needle spectra measured by the contact probe and integrating sphere, spectra of...
Optical properties of the leaf in relation to its anatomical traits
Neuwirthová, Eva ; Albrechtová, Jana (advisor) ; Tomášková, Ivana (referee) ; Písek, Jan (referee)
Plant functional traits at the leaf level are commonly used to predict ecosystem responses to environmental factors and describe global climate change processes at the ecosystem level. Plant functional traits include both leaf biophysical traits (e.g., photosynthetic pigment content and water content) and structural traits (e.g., leaf thickness and proportion of photosynthetic and non-photosynthetic tissues). Leaf biophysical and structural traits can be detected either destructively in the laboratory or non-destructively using leaf optical properties. Although estimating chlorophyll content from leaf optical properties is a well-established methodology, the influence of leaf structure and internal anatomy on leaf optical properties has only been thoroughly studied in the last two decades. The papers included in my thesis and my thesis itself are mostly focused on the study of typical European deciduous trees of temperate and hemiboreal forests with leaves having a dorsiventral structure (i.e., the mesophyll is differentiated into palisade and spongy parenchyma). Furthermore, my thesis includes a study on the effect of leaf surface structural traits on optical properties. In this study, two groups of phylogenetically close herbs with comparable internal leaf structure were used (mutants of...
Laboratory/Field Spectroscopy and Remote Sensing Image Data for Vegetation Studies
Červená, Lucie ; Kupková, Lucie (advisor) ; Pavelka, Karel (referee) ; Müllerová, Jana (referee)
Dominant vegetation species of two structurally and functionally different montane ecosystems were studied by means of laboratory and field spectroscopy and remote sensing image data: (1) a homogeneous human-influenced evergreen coniferous forest represented by a Norway spruce forest in the Krušné hory Mountains and (2) a heterogeneous natural ecosystem of a relict arctic-alpine tundra in the Krkonoše Mountains with predominance of grasses. The first part dealing with the Norway spruce forest is especially focused on the methods of laboratory spectroscopy. The assessment of Norway spruce stands on a regional and a global scales requires detailed knowledge of their spectral properties at the level of needles and shoots in the beginning, but ground research is very time-demanding. Open spectral libraries could help to get more ground-truth data for subsequent analysis of tree species in forests ecosystems. However, the problem may arise with the comparability of spectra taken by different devices. The present thesis focuses on a comparability of spectra measured by a field spectroradiometer coupled with plant contact probe and/or two integrating spheres (Paper 3) and proves the significant differences in spruce needle spectra measured by the contact probe and integrating sphere, spectra of...
The effect of leaf structure on the leaf optical properties - Implication for water regime.
Neuwirthová, Eva ; Albrechtová, Jana (advisor) ; Rothová, Olga (referee)
Due to coal mining activities, heap substrates rich in clays with poor water permeability and lack of nutrients are relocated outside of mines representing hostile environment to the majority of vegetation. A material from the surface coal mines in Sokolov forming the Velká Podkrušnohorská Heap (VPS) form large locality showing characteristics of anthropogenically devasted landscape. The aim of the present study was to compare leaf structural and biochemical parameters with relation to a leaf reflectance of two pioneer tree species Salix caprea and Populus tremula with regard to leaf water regime and leaf adaptation to a water loss. From the methodological point of view, the study aimed on contribution to determine relation of selected leaf structural parameters to leaf reflectance what has not been intensively studied yet. The foliage of trees P. tremula and S. caprea grown on succession localities S2 a S3 for 30 years was used as a material for my study. The material was studied for its structure using the leaf cross sections nd abaxial epidermal strips (thickness of the leaf tissue layers and of a leaf, stomatal size density and area). Other studied parameters were contents of photosynthetic pigments, specific leaf area (SLA), water potential and leaf reflectance in regions of photosyntetically...

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