In this thesis, the methodological problems arising from the peculiarities typically encountered in BEF-studies as well as the resulting challenges in the ecological interpretation of the role of plant polyphenolic substances are investigated. Moreover, a study on their role in litter decomposition along a gradient of secondary forest succession is part of this PhD thesis. In addition, the phylogenetic patterns in the development of polyphenolic concentrations in plant leaves are the subject of the third study in this thesis. Finally, this thesis contains an optimized protocol as well as practical guidelines for the sample collection, processing and quantification techniques with respect to plant polyphenols in BEF-studies. |