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Influence of local woody species coverage on herb vegetation on a small spatial scale
Kubát, Miloš ; Vojta, Jaroslav (advisor) ; Roleček, Jan (referee)
English abstract This work aims on influence of local coverage of woody layer on understorey herbs. Expansion of woody species into semi-natural grassland ecosystems is accompanied by increase of local coverage of woody layer. This process leads to changes of environmental conditions in understorey, that is followed by extinction of heliophillous herb species. This works deals with this phenomenon on a small spatial scale. The research took place near former village Tocov, situated in an abandoned landscape in Doupovské hory. This locality is typical example of woody species expansion into species rich grassland. Here, 399 phytocoenological relevés were collected. These relevés are ordered into triplets, that make triangles. There are local coverage of woody layer measured for each relevé. Impact of this variable was tested in two sizes of the observation window. Single relevés present microsites, while whole triplets present sites, where variability of local covarage of woody layer, leading to variability in herb layer, could be distinguished. Number of herb species is linearly negatively correlated with local coverage of woody layer on a smaller scale of single relevés. In whole triplets, increase of local coverage of woody layer, during early stages of woody species expansion, doesn't lead to decrease of...
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