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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Kvantitativní parametry cév listnáčů jako nástroj pro rekonstrukci fyzickogeografických procesů / Quantitative vessel parameters of broadleaves as a tool for reconstruction of physical geographical processes

Tumajer, Jan January 2018 (has links)
Trees adjust wood anatomical structure to environmental conditions, predisposing time series of quantitative wood anatomical parameters to be valuable source of palaeoenvironmental information. In this doctoral project we analysed the response of vessel parameters of i) floodplain Quercus robur to groundwater level fluctuation, hydroclimate variability and extreme events (droughts and floods), and of ii) Betula pendula to mechanical damage caused by various disturbances. Although climatic signal as well as pointer years stored in tree-ring width chronologies of Quercus robur largely differ between sites, quantitative vessel parameters contain spatially- homogenous positive signal of previous year summer temperature and current year winter/early spring temperature. The only between-site difference in wood anatomical chronologies is negative effect of moisture on vessel size in floodplain, which does not occur in not-flooded lowland sites. We suggest that while tree productivity benefits from high water availability, the wood anatomical structure of Quercus robur is constrained by high soil water saturation in floodplain zone. In addition, the response of tree-ring widths to moisture availability is not uniform inside single stand, but subgroups of trees with completely opposite response coexist...

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