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Holocene fire history of forest vegetation in central Europe based on soil and sedimentary charcoal
Bobek, Přemysl ; Kuneš, Petr (advisor) ; Feurdean, Angelica (referee) ; Chytrý, Milan (referee)
Fire is a fundamental environmental factor that directly shapes many terrestrial ecosystems on Earth. The present thesis attempts to provide a comprehensive overview of the fire dynamics in Central Europe over the course of the last 12,000 years. Based on extensive analyses of charcoal particles deposited in terrestrial and lacustrine sedimentary sequences and carbonized plant tissues deposited in soils, I was able to track past fire dynamics across a range of spatial scales - from the forest stand scale to the landscape scale. First, we described relationships between drivers of recent fire occurrence and proposed linkages to the spatial pattern of Late-Holocene biomass burning. We found factors related to relief characteristics, such as increased thermal flux or terrain roughness, to be important determinants of fire occurrence within the present-day landscape. Contrary to all expectations, anthropogenic drivers seem to have a weak influence at present. Because relief-based factors have been stable throughout the Holocene, it seems probable that habitats of certain types are more predisposed to increased burning. We hypothesized that recurrent fire disturbances may contribute to the long-term maintenance of Pinus sylvestris-dominated forests, which withstood the competitive pressure of broadleaf...
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Vegetation changes in Czech lowland forests over the past decades
Kopecký, Martin ; Hédl, Radim (advisor) ; Chytrý, Milan (referee) ; Diekmann, Martin (referee)
Vegetation changes in Czech lowland forests over the past decades Martin Kopecký ABSTRACT To explore decadal changes in plant species diversity and composition of typical lowland forests in the Czech Republic, I compared vegetation on plots sampled decades ago with vegetation on the same plots sampled recently. First I evaluated the robustness of the approach used in my thesis. In Chapter 1, we provided the first direct test of the effect of uncertainty in original plot location on results from vegetation resurvey. We found that temporal trends in vegetation diversity and composition were comparable between exactly relocated permanent and only approximately relocated semi-permanent plots. Therefore, we conclude that the resurvey of semi-permanent plots is robust to the uncertainty in original plot location. Then, we showed that vegetation in lowland oak forest shifted from species-rich communities of thermophilous forest toward species poorer communities of mesic forest (Chapter 2). The species typical for thermophilous oak forests and nationally endangered species suffered the most significant decline. We identified as the main driver behind these changes shift from traditional coppicing toward high forest management after WWII. Further, we explored the processes behind temporal shifts in species diversity...
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Palynological synthesis for the Czech Republic
Abraham, Vojtěch ; Pokorný, Petr (advisor) ; Chytrý, Milan (referee) ; Sugita, Shinya (referee)
The aim is to gather pollen sequences and derive from them synthetic information on past species distribution and Holocene vegetation history. Lonicera nigra was selected as a model taxa. The phylogeographic hypothesis that its Alpine and Carpathian populations survived the LGM in separate refugia is supported only by the Late-Glacial record. This shrub migrated rapidly from southern to central Europe during the warm oscilations of the Late Glacial. The synthesis of vegetation history was produced by applying the REVEALS model, which can filter out following factors influencing the relationship between pollen and vegetation: pollen taphonomy, pollen productivity and pollen dispersal. It was necessary to calculate and test those parameters, so the goals were partly methodical. Pollen productivity estimates are calculated within the Relevant Source Area of Pollen, which is influenced by vegetation structure. Subsequent validation of those values in the area of the REVEALS model 10000 km2 and selection of additional values for lacking taxa created the best set of parameters for the study area. The source fossil dataset for purposes of this synthesis is the newly developed Czech Quaternary Pollen database (PALYCZ). Non-direct multivariate analysis of pollen percentages including all taxa revealed a similarity...
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Vliv hospodářských zásahů na změnu v biologické rozmanitosti ve zvláště chráněných územích: Vliv různých managementových zásahů na vegetaci vřesovišť v Národním parku Podyjí II.
Mendelova zemědělská a lesnická univerzita v Brně, Ústav půdoznalství a mikrobiologie, Brno ; Masarykova univerzita v Brně, Přírodovědecká fakulta, katedra botaniky, Brno ; Botanický ústav AV ČR, Průhonice, pracoviště Brno ; Záhora, Jaroslav ; Chytrý, Milan ; Tůma, Ivan ; Holub, Petr ; Sedláková, Iva
V roce 1992 byly založeny pokusy, které měly ověřit, zda vypalování, kosení a odstraňování drnů jako tradiční typy managementu západoevropských vřesovišť povedou k obnově a zmlazení vřesovišť v NPR Podyjí. Dále bylo v roce 2000 založeno 30 nových ploch na studium vlivu pastvy a kosení. Od roku 2000 je také sledována dynamika mikrobiálních transformací dusíků v půdě, rychlost rozkladu opadu a efektivita využití N a P rostlinami. V roce 2001 byly na vřesoviště naistalovány srážkoměry.
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Vliv hospodářských zásahů na změnu v biologické rozmanitosti ve zvláště chráněných územích: Vliv různých managementových zásahů na vegetaci vřesovišť v Národním parku Podyjí III.
Mendelova zemědělská a lesnická fakulta v Brně, Ústav půdoznalství a mikrobiologie, Brno ; Masarykova univerzita v Brně, Přírodovědecká fakulta, katedra botaniky, Brno ; Botanický ústav AV ČR, Průhonice, pracoviště Brno ; Záhora, Jaroslav ; Chytrý, Milan ; Fabšičová, Martina ; Tůma, Ivan ; Holub, Petr ; Sedláková, Iva
Pokusy mají za cíl otestovat některé metody managementu vřesovišť: vypalování, pokosení drnů, pastvu. V této vegetační sezóně bylo sledováno celkem 38 trvalých ploch na vřesovištích v NP Podyjí. Od r. 2000 je také sledována dynamika mikrobiálních transformací dusíku v půdě, rychlost rozkladu opadu a efektivita využití N a P rostlinami.
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