Bachelor Thesis

Einfluss von Planzendiversität, Gesellschaftszusammensetzung und Umweltparametern auf die Produktivität (Biomasse) in montanen Mähwiesen im Bayerischen Wald

Manuel Hasch (04/2012-10/2012)

Support: Carl Beierkuhnlein

Triggered by the man-accelerated climate change, a strong alternation of ecosystem processes like transport, conversion and storage of materials is expected in near future (Götzl et al., 2011). To allow a proper respond it is necessary to create a scientific background for discussion. As a consequence a discourse regarding relevant processes and properties has developed in recent years (Assaf et al., 2011), which is the starting point for this thesis. Within its framework a field study has been done on different hay meadows in the ‘Bayerischer Wald’ to investigate the productivity of ecosystems based on the net above-ground productivity. The impact of environmental factors is demonstrated relating to productivity, in particular the influence on productivity by biotic factors in form of species composition, α-diversity and functional groups is analysed. The interaction with abiotic parameters (pH, soil moisture, slope, height above sea level, soil type, geodetic coordinates and exposition) has also been investigated to achieve more consistent conclusions. As a result no relation between the biotic local characteristics and the productivity of the investigated ecosystems based on the collected data was gained. On the other hand a significant effect on species composition, functional groups as well as productivity of the investigated ecosystems can be established according to abiotic location characteristics, especially considering spatial distribution and slope. The influence of biotic characteristics has already been shown in different controlled experiments, where legumes and a high α-diversity increased productivity (Scherer-Lorenzen, 1999). Those results could not be approved in the framework of this thesis, which leads to the assumption that in a cultural environment those relations are dominated by additional effects. Thus, the biotic local characteristics might be regarded a less determining factor in real ecosystems than suggested in controlled experiments. This study shows that the impact of anthropogenic use, climate conditions and relief structure on the productivity of hay meadows needs to get more attention. To better address the problems induced by climate change and the effect of biotic and abiotic factors on productivity, extensive observational research and supraregional studies are needed.