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Intraspecific trait variability of herbaceous plants in organic and conventional olive plantations in region at desertification risk
MIGLIORINO, Michele
This thesis is an ecological study in an agricultural context (agroecological research). It is carried out in olive plantations in south Italy, Apulia, a region at strong desertification risk. The effect of agricultural management (organic vs. conventional) is investigated on i) the herbaceous species composition ii) intraspecific trait variability of five selected herbaceous plants iii) soil conditions. Herbaceous plants are here considered as "indicators" of olive plantations' health. Studying if and how species traits and soil parameters vary with management, should reveal how olive understory grasslands are responding to increasing drought conditions and other desertification constraints. Management of grasslands and soils is critical to maintain high ecological functionality and services of olive agroecosystems.
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Adaptations of terrestrial arthropods and especially arachnids to arid environmental conditions
Byronová, Markéta ; Starostová, Zuzana (advisor) ; Opatová, Věra (referee)
The biggest problem that terrestrial animals have to deal with is the risk of dehydration. Water is lost by evaporation during respiration and through the body surface, during excretion and various secretions. Terrestrial animals developed various physiological, morphological and behavioral adaptations against water loss. This work summarizes the knowledge about adaptations against water loss in arthropods in arid environmental conditions. It focuses on arachnids and especially on scorpions, which are widespread in arid areas and show high resistance to extreme desert conditions. The work examines the influence of environmental conditions on physiological processes in the body, morphological adaptations and behavioral changes. It defines specific adaptations of scorpions and describes in more detail the role of the hepatopancreas in maintaining the balance of fluids in the body and the subsequent changes in the osmolarity of hemolymph. Key words: evaporation, aridity, water balance, arthropods, arachnids, scorpion
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Evaporative water loss in geckos of the genus Paroedura
Myslíková, Tereza ; Starostová, Zuzana (advisor) ; Okrouhlik, Jan (referee)
Keeping a balanced state in terms of liquids in an organism, especially evaporative water loss regulation, is essential for all terrestial animals, including reptiles. Respiratory water loss and cutaneous water loss account for the highest percentage of total water loss. For this reason, the degree of evaporative water loss in reptiles can be primarily influenced by body dimensions, metabolism intensity and morphology of body surface scales. This thesis focuses on water loss through evaporation in Madagascan Paroedura geckos. The Paroedura are suitable for this research because they represent a monophyletic genus with a strongly supported hypothesis about phylogenetic relationships. The thesis adds some facts to this theory. At the same time, individual Paroedura species differ in body dimensions and habitat preference. The aim of the thesis was to find out whether individual representatives of Paroedura differ in TEWL, to specify the characteristics of the ancestral state of TEWL in this genus and to test which morphological and physiological factors influence TEWL. Further aim was to measure cutaneous water loss. Measuring was carried out by flow- through respirometry. The results show that individual representatives of Paroedura differ remarkably in TEWL figures. The reconstruction of the...
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Evaporative water loss in terrestrial vertebrates
Demešová, Jana ; Starostová, Zuzana (advisor) ; Vohralík, Vladimír (referee)
Evaporative water loss affects physiology, ecology and evolution of individual organisms. This wok summarizes the knowledge about water loss in main groups of terrestrial vertebrates. In addition to physiological processes, it also follows evolutionary trends through adaptations created as a barrier against the water loss or as a method of cooling by evaporation. From an ecological point of view, it examines whether these adaptations have enabled some of them to inhabit extreme habitats. The topic of water loss by evaporation interferes with other topics such as thermoregulation or metabolism. Key words: evaporation, water loss, aridity, thermoregulation, metabolism, vertebrate
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