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Functional diversity of flowers in alpine plant communities
Plachtová, Kateřina ; Sklenář, Petr (advisor) ; Koupilová, Klára (referee)
Alpine environment differs from other biomes with its special abiotic conditions, which may influence local plant communities. Species composition of plant communities' changes along the altitudinal gradient. So do its vegetative and generative functional traits, as well as abundance and species composition of their pollinators. This thesis mainly examines floral functional traits (morphology, color and chemical traits of flowers) and their diversity along altitudinal gradient. It attempts to find general trends that characterize altitudinal changes of these traits. Most crucial drivers are pollinators and abiotic factors of environment. Functional traits of alpine plants change in response to variation in abundance and species composition of pollinators. Since dominant pollinators in the alpine environment are Diptera, floral functional traits of local plant communities are adjusted according to their preference. However, floral functional traits are also depending on abiotic factors, which can have an opposite effect compared to biotic factors. Considering the complexity of alpine plant communities and also the complexity of the drivers, which influence them, it's extremely difficult to find unambiguous patterns to describe these changes. Nevertheless, some trends in the altitudinal changes of...
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Recognition of predators in vertebrates: innated or learned?
Antonová, Kateřina ; Fuchs, Roman (advisor) ; Adamová, Dana (referee)
Predator recognition is the prerequisite for antipredatory behaviour. The ability to recognize predator may be inborn or acquired. The mammals as well as majority of birds have common care for brood. Many of both groups form more or less complicated societies. All those support naive individuals in acquiring knowledge of predators through the social learning that is not as risky as learning through experience. Studies of inborn or acquired recognition as applied by mammals and birds may bring generalized closures about various learning forms by both of these groups. Surprisingly, no systematic observations were made to the matter. As recent studies show, the naive mammals and birds may recognize predators, no conforming results were presented yet. Obviously, the recognition is depending on the incentives presented. Alive predator invokes more intensive response than any model, while the olfactory efficacy depends on the carrying medium. The recent studies in an integrant part neither allow to determine experimental precision. To do so, much larger volume of predators and controls should be made. However, studies of the kind are rare. Studies of mammal and birds' inborn and acquired predator recognition still remain the attractive research theme. Keywords: predator, recognition, innated, learned,...
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