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Arsenic and cadmium are both non-essential, highly toxic and carcinogenic elements that often occur together in the environment. Given the frequent co-contamination of the environment, it is necessary to investigate both plant strategies for dealing with one metal(loid) and the mechanisms that lead to tolerance or, conversely, sensitivity in the presence of both elements. Simultaneous exposure to multiple toxic elements may lead to extensive plant damage, however it may also result in the increasing engagement and intensity of defence strategies. Contamination of the food chain through crops growing on contaminated soils is a major concern, one that poses a risk to both human and animal lives. The aim of this research field is to reduce accumulation and translocation to aboveground edible parts as much as possible, for example by understanding the mechanisms behind heavy metal accumulation and translocation, or by stabilising toxic elements in the soil, or by cleaning up contaminated soil. One method of clean-up is phytoremediation, which usually utilizes plants with high tolerance to toxic elements, called hyperaccumulators. The knowledge of how defence strategies and mechanisms are affected by the interaction of multiple elements is important for identifying plant species capable of activating...

6 Abstract In recent decades the field of fluvial geomorphology has moved towards the most detailed and comprehensive description of the processes in fluvial systems. The recent development of UAVs (Unmanned Aerial Vehicles) has been a major contribution in analysis of fluvial processes, it provides very detailed data for change analysis. This thesis deals with the analysis of recent fluvial dynamics using UAV. The theoretical part of the thesis summarizes the current theoretical and methodological knowledge from the study of fluvial dynamics and also presents the general principles of UAV monitoring with its use in fluvial-geomorfological research. Recent fluvial dynamics was evaluated in the stretch of Javoří brook in Šumava Mountains where the long-term research is conducted by the Department of Physical Geography and Geoecology. Causal runoff events with an impact on fluvial dynamics were identified on the basis of the analysis of hydrometeorological data covering hydrological years from 2016 to 2020. A total of fourteen events exceeded the threshold of channel-forming discharge Q = 5,041 m3 ·s−1 in the investigated period. Geometrical, morphological and volume changes were evaluated based of the photogrammetric reconstruction of the riverbed during three successive scannings (2015, 2018, 2020). The...