• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 24
  • 2
  • Tagged with
  • 26
  • 6
  • 5
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
21

Fenologická pozorování ve smrkovém porostu na ekosystémové stanici Rájec, Drahanská vrchovina

Mizerová, Lucie January 2019 (has links)
This diploma thesis evaluates the commencement of phenophases considering the changing microclimate conditions in the habitat of Norway spruce (Picea abies /L./ Karst) in a young and a mature spruce monoculture at the ecosystem station Rájec. The phenology of spruce undergrowth has also been under observation. Regarding the methods, above-ground phenology and observation by means of phenocams have been used. The results have been compared not only among themselves but also in the context of long-term averages. Thanks to the fact that phenophases of forest woody plants and herbaceous plants are dependent on climate conditions, the results of long-term phenological observations are a conclusive indicator of climate changes. The results of this diploma thesis can be a contribution to the phenology database.
22

Vliv klimatu na termíny fenologických fází vybraných živočišných druhů

Tarrová, Adéla January 2017 (has links)
Thesis on "Climate Impact on the Terms of Phenological Phases of Selected Animal Species" examines climate change and its impact on the shift of phenological terms of selected birds population in a long-term period. It also examines the interdependence between phenological terms of selected bird species. Finally, it also focuses on the relationship between managed (fruit trees) and unmanaged ecosystems (bird species). The study is based on the data which were monitored at three sites in southern Moravia during the years 1961 - 2012. The data were compared between each other in time series. The results show a significant increase of temperature in the monitored period with an evident impact on the earlier onset of selected phenological terms. Similarly, the relationship between the individual phenological dates of managed and unmanaged ecosystem is also evident.
23

Hybridizace orobinců Typha latifolia a T. angustifolia / Hybridization of cattails Typha latifolia and T. angustifolia

Mašterová, Helena January 2013 (has links)
This study investigates the hybridization of two species of cattails, Typha latifolia (Common Cattail) and T. angustifolia (Narrow-leaved Cattail) in the Czech Republic. The aim of this study was to determine, how often T. latifolia and T. angustifolia hybridize, whether hybridization is allowed by overlapping flowering time of these species and whether it is possible these species controlled cross in a culture. For detection of hybrid individuals were used microsatellite DNA markers, which allow to detect hybridization events and differentiate hybrids from the parental species. Molecular analysis revealed that hybridization of T. latifolia and T. angustifolia occurs in the Czech Republic, but it is not frequent. Of the 267 analyzed individuals, 130 individuals were pure species T. latifolia, 108 individuals pure species T. angustifolia and 29 individuals were hybrids. Of the hybrids, 23 were advanced hybrids, 5 were backcrosses and only one individual was F1 hybrid. Flowering time of T. latifolia and T. angustifolia overlaps, which allows hybridization, and flowering time to not act as a prezygotic reproductive isolation barrier and gametes T. latifolia and T. angustifolia can blend together. In controlled crosses the female spikes T. latifolia and T. angustifolia created seeds, but these were...
24

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...
25

Evaluation of water use efficiency of short rotation poplar coppice at Bohemian-moravian highlands

Hlaváčová, Marcela January 2014 (has links)
The diploma thesis provides basic characteristics of short rotation coppice plantations, then the most significant short rotation coppice species cultivated in the Czech Republic are described. The detailed description of particular Populus L. clone J-105 grown at the plantation of the Test Station Domanínek Ltd. follows. Afterwards, key determinants of short rotation coppice yield are presented in the text. The last theoretical part of the thesis deals with water use efficiency (WUE) with emphasis on the method used at the experimental plantation in Domanínek. The methods of sap flow measurements and biomass determinations are described for this purpose. The main aim of the practical part of the thesis is to determine WUE of 16 measured trees where sap flow measuring systems were installed. These trees are divided into 3 cohorts according to diameters at breast height (DBH) at the beginning of the growing season 2013. The additional measurements were carried out: phenological imaging, soil moisture measurements, LAI measurements and sapwood area determination. The statistical analysis of WUE did not show any statistically significant differences between values of WUE for individual cohorts. Only in May, the statistically significant difference between cohort 1 (trees with the thickest stems) and cohort 3 (trees with the lowest values of DBH) appeared.
26

Topoklima údolí a jeho vliv na vegetaci / The Valley's Topoclimate and Its Influence on the Vegetation

Kuželová, Hana January 2012 (has links)
The Valley's Topoclimate and Its Influence on The Vegetation Abstract The thesis as presented deals with specific valley's topoclimate of a chosen example of one particular valley located near the city Jílové u Prahy. The main objective of the thesis which has been defined is to evaluate the topoclimate of the determined area and its influence on the phytogeographical and phenological situation of the valley. The outdoor temperature measurements carried out by using Assmann's psychrometer as well as the observations of the plant's phenological state have been taken in the course of repeated expeditions into the valley in 2011 and 2012. The formations of night valley's inversions have been confirmed. The temperature gradient of 6 řC and three and half an hour long inversion following the sunrise have been recorded as a result of the measurement performed on 28th April 2012. As a consequence of the valley's parts shading the temperature differences have been proven. As a referential meteorological station the faculty's own station situated on the peak of Pecný hill and the automated personal weather station in Okrouhlo were used. The lower temperatures in the valley have a clear impact on the commencement of the plant's phenological stages. A detailed phenological scale was created in order to observe...

Page generated in 0.327 seconds