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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Fungování arbuskulární mykorhizy ve vztahu ke složení společenstva hub a podmínkám prostředí / Functioning of arbuscular mycorrhiza in relation to fungal community composition and environmental conditions

Voříšková, Alena January 2019 (has links)
Arbuscular mycorrhizal (AM) symbiosis, a widespread plant-fungal relationship, is based on reciprocal resource exchange. The functioning of this fragile relationship balances on the scale from mutualism to parasitism, depending on the specific context. The thesis aims to interlink the functioning of AM symbiosis both with the composition of AM fungal communities and with different abiotic conditions. The thesis is divided into a methodological and a factual part and consists of three publications and one manuscript. All experiments were conducted in greenhouse conditions with medic (Medicago sp.) as host plant. Host plants were inoculated with single AM fungal species in Paper I and II, and with a synthetic AM fungal community of five species in Paper III and IV. The host plant identity, the amount of phosphorus (P) in substrate and the type of substrate played an important role for the achievement of mutualistic AM symbiosis, as demonstrated in Paper I. Paper II showed that mitochondrial and nuclear qPCR markers can be used alternatively for the quantification of particular AM fungal species. However, intraradical fungal biomass was better related to copy numbers of nuclear DNA than of mitochondrial DNA. The functioning of AM symbiosis was modulated by the availability of P, light and water,...
182

Faktory určující rozšíření druhů suchých trávníků / Factors determining distribution of species in dry grasslands

Průchová, Dana January 2010 (has links)
Factors determining distribution of species in semi-natural grasslands Survival and colonization of plant species in fragmented landscapes are topic of many recent studies. Most of them deal with one or just a few species or with overall species diversity. There are also a lot of studies devoted to the effect of abiotic characteristics and other parameters of fragmented habitat patches. Studies that would enable to evaluate behaviour of a large number of individual species are still relatively rare, especially in case of grassland species. Comparison of species traits in conjunction with the knowledge of type of historical land use and abiotic requirements of species can be a key to understanding of current species dispersal and their regional dynamic in fragmented landscape. This method of prediction of species dispersal can be a good implement for landscape planning and conservation of species and also their habitats. Goal of my thesis was to determine which traits of species influence response of species on land-use history in fragmented habitat of dry grasslands. I tried to use effect of land-use history without effect of environmental factors on species composition in phytosociological relevés. Then I tried to explain the reaction of species through their traits. I focused partially on traits...
183

Archeobotanická data jako nástroj poznání minulosti synantropní vegetace - metodická studie zaměřená na vlastnosti rostlin / Archaeobotanical data as a tool for understanding history of synanthropic vegetation - a methodological study focused on traits of plants

Mrkvičková, Kateřina January 2021 (has links)
Archaeobotanical data are often a mixture of material of different origins. The formation process of archaeobotanical records can often be different. Hence it is important to understand the structure of these fossil records before the data are used for various reconstructions and interpretations. The aim of my diploma thesis is to identify the taphonomic causes of differences between synanthropic species from different archaeological sites using plant traits. The greatest differences between sets of species in archaeobotanical situations are due to the way of preservation, ie. between charred and non-charred (waterlogged) macro-remains. My diploma thesis is based on data from the Archaeobotanical database of the Czech Republic. I focused on the Middle Ages, which is the best period in terms of the number of species and the number of sites. Using multidimensional analyses, I examined the structure of archaeobotanical data and then selected a relevant dataset to examine the differences in species composition between different types of conservation. After that I correlated the results with the species traits. I found that the structure of archaeobotanical data is very heterogeneous. In each of the two types of conservation, different species are preserved. These species are characterized by a...
184

Vliv květních zdrojů na specializaci pestřenek v železnohorských lučních společenstvech / Effect of floral rewards on specialization of hoverflies (Diptera, Syrphidae) in meadows of Železné hory

Filip, Jan January 2021 (has links)
Traditionally managed temperate semi-natural meadows are generally considered as one of the most diverse habitats worldwide. During the past decades, management changes and abandonment of meadows pose serious threats to communities of both flowering plants and pollinators. However, the extent to which are pollinators affected by changes in floral resources still remain unknown. To investigate the effect of floral resources on visitation specialization, species richness and abundance of hoverflies, pollination networks from 13 meadows in the Železné hory PLA were constructed and analysed. Moreover, patterns were recorded on two spatial scales, in transects and in the whole meadows. To specify the specialization of hoverfly pollinators, unvisited plant species and all resources present on a site (transect/meadow), offered by plants as floral abundance and nectar rewards, was added in the networks. Relationships between plant species richness, floral abundance and nectar sugar production were positively correlated with visitation specialization of hoverflies on the meadow scale. Species richness and abundance of hoverflies was affected by floral resources on the transect scale, unlike the specialization of hoverflies. The usage of extended network indices may act as an improvement towards the better...
185

Fyziologie rostlin ve výuce botaniky na základních školách / Physiology of Plants in Elementary School Botany

Sochorová, Markéta January 2011 (has links)
This thesis on the topic "Physiology of Plants in Elementary School Botany" consists of theoretical and practical part. The theoretical part focuses on a didactical analysis of the textbooks currently in use and integration of this topic in the valid curricular documentation. It also includes a research part, in which the possibilities of material visual aids used in science teaching are identified. The practical part makes use of these observations. A interactive CD, which includes worksheets on the main areas of plant physiology, has been created based on these observations. The worksheets are in educational text form, include gap-filling activities, and practical - with appropriate experiments. To these, methodology notes for teacher are supplied. The complete version is on the attached CD. Keywords: plant physiology, textbook didactical analysis, worksheet, experiment suggestions, video-material
186

FENOLOGIE DŘEVA STROMŮ A KEŘŮ NA HORNÍ HRANICI LESA V ZÁVISLOSTI NA MIKROKLIMATICKÝCH PODMÍNKÁCH / MICROCLIMATIC INFLUENCES ON WOOD PHENOLOGY OF TREES AND SHRUBS IN TREELINE ECOTONE

Hejda, Tomáš January 2019 (has links)
This thesis deals with the influence of microclimatic conditions (air temperature near tree/shrub top, temperature of the stem and root zone) on the wood phenology of trees (Picea abies) and shrubs (Pinus mugo) growing on the same site in the alpine tree line (ATL) ecotone. Phenological and microclimatic research was carried out in the Giant Mountains at 1,370 m a. s. l. in the 2017 vegetation period, with the aim to compare the course of wood formation depending on the microclimate, to determine the temperature thresholds of wood growth and differences in the morphology of trees and shrubs. Based on the microclimate analysis of trees and shrubs, individual variables were determined (average, average minimum, average maximum, daily amplitude of air, stem and root zone temperatures) characterizing the growing season. The collection of micro-drills of trees and shrubs took place from April to October in an interval of 6 - 11 days, which were subsequently processed and examined in the laboratory. The following phenophases of wood development were distinguished: cambial, enlarging, wall-thickening, mature cells and cells of the previous ring. Subsequently, differences in the number of cells of individual phenophases were identified between trees and shrubs. Furthermore, the temperature thresholds for...
187

Ekologie patosystému Vinca minor - Puccinia cribrata v přirozených populacích / Ecology of the pathosystem Vinca minor - Puccinia cribrata in natural populations

Vaníček, Jiří January 2019 (has links)
5 Absctract Environment and demographic characteristics of host population are important factors affecting incidence and severity of plant diseases. The aim of this study was to reveal possible effects of microclimatic and edaphic characteristics and host population demographic factors on the biotrophic pathogen Puccinia cribrata, microcyclic rust parasitising clonal evergreen plant Vinca minor. I studied the ecology of this pathosystem in natural populations of V. minor in the Soča valley in the Julian Alps in Slovenia. Rugged terrain of the Soča valley with different bedrocks allowed to study pathogen distribution at topographically diverse forest and scrub sites, greatly differing in soil depth and canopy structure. P. cribrata was significantly more likely to occur in the themophilous forest with shallow calcareous soils and open canopy than in the mesophilous forest types. Its prevalence (proportion of diseased stems in population) was also highest in this type of vegetation. Most important host population factors were population size and population density positively affecting incidence and prevalence respectively. Additionally, I tested various vegetation and topographic indexes derived from remote sensing for usability in prediction models. It appears that vegetation indexes connected with canopy...
188

Přispívá vodní stres a mezidruhová konkurence k funkční konvergenci nebo divergenci vlastností mokřadních rostlin? / Does water stress and interspecific competition contribute to the functional divergence or convergence of wetland plant species?

Műnichová, Radka January 2017 (has links)
This diploma thesis is based on the experiment which took 5 years. In 52 plastic containers were planted four species wetland plants; two species of grasses (Calamagrostis canescens and Deschampsia cespitosa) and two species of sedges (Carex elata and Carex elongata). Three types of water regime were set up with: high, low and fluctuating water level, where the high and low level of water took turns after one year. One year before the data collection the strongest competitor Carex elata was cut out. For the evaluation of the role of water level (environmental stress) and removal of the dominant (competition) we selected two functional trait indicators: specific leaf area (SLA) and leaf dry matter content (LDMC). SLA is an indicator of resource strategies, competitiveness and efficiency of light photosynthesis. Species with high SLA are usually better competitors for light, but tolerate harder the environmental stress. LDMC reflects a plants investment in persistent leaf structures and therefore in nutrient retention. A significant effect of water regime on LDMC was observed in the species Deschampsia cespitosa that had higher average values of LDMC in dry water regime, which is indicating higher investment into persistent leaf structures. And the effect of the dominant removal on SLA, where the values of SLA in the containers without removed dominant were higher. Increased SLA implies increased intensity of competition for light. My diploma thesis supported that specific leaf area and leafdry matter content are important functional indicators different types of stress conditions in wetland communities.
189

Integrovaná produkce ovoce a zeleniny v ČR / Integrated Production of Fruit and Vegetable in Czech Republic

KOŽUŠNÍKOVÁ, Eva January 2017 (has links)
The purpose of this dissertation is to specify the issues of integrated production of fruit and vegetables in the Czech Republic. Furthermore, the paper aims to capture the current situation based on completed surveys which were distributed among consumers, producers and complementary distributional units.
190

Capacidad ecologica productiva de los ecosistemas aluviales de Salix alba L., Populus alba L., y Populus tremula L. al sur de Moravia-Europa Central

Manjarrés, Diana del Rocío López January 2008 (has links)
No description available.

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