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Gewählte Doctoral Thesis:

Jörg Böckelmann (2017): THE ROLE OF THE SOIL DIASPORE BANK AS AN INTEGRAL PART OF THE LIFE HISTORY OF THE ECOLOGICALLY EXTREMELY SPECIALISED EPHEMERAL, SEMI-AQUATIC PLANT SPECIES CYPERUS FUSCUS.
Doctoral Thesis - Institut für Botanik (Botany), BOKU-Universität für Bodenkultur, pp 131. UB BOKU obvsg FullText

Data Source: ZID Abstracts
Abstract:
The brown galingale Cyperus fuscus L. (Cyperaceae) is a typical representative of the semi-aquatic pioneer vegetation of the land interface zones along the shores of natural rivers. It also grows in secondary anthropogenic habitats such as traditionally used fishponds and fish storage ponds with different hydrological regimes. The short-living species are adapted to regularly occurring flooding stress and unsuitable periods are survived by the maintenance of an enormous soil seed bank in the soil. Over 30 populations according to the three habitat types were surveyed including the soil seed bank in Central Europe and additionally 49 populations across Europe were sampled. Our results suggest that differences in growth between primary and secondary habitats are both, genetically fixed and caused by the growing conditions at the localities (e.g. high nutrient availability in fishponds). Cyperus fuscus follows the typical low-oxygen escape strategy to survive flooding in all habitats, but plants of the near-natural rivers are better adapted. However, in the secondary sites, evidence of a disruptive selection was found regarding the plasticity of the response to flooding. To our knowledge the first analysis of genetic variation for an ephemeral mudflat species isolated in space and time was performed with 21 de-novo described microsatellite markers. The river populations have to be evaluated as more genetically diverse, due to higher gene flow, whereas in the secondary habitats adaptations to the changed conditions have taken place. A differentiation between soil seed bank and surface populations could not be found, what suggests a reservoir of genetic variation storing genotypes from earlier generations and migrants. The species shows high spreading potential and seems to have survived the last ice age in southern refugia. Thus, the protection of secondary and primary habitats is recommended to maintain the whole variation and adaptive potential of a species.

Betreuer: Bernhardt Karl Georg
1. Berater: Tremetsberger Karin
2. Berater: Grausgruber Heinrich

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