Project description B6

Scientific advisors
apl. Prof. G. Gleixner

project
Effect of tree diversity on the microbial diversity (PLFA-profiles), and the effect of water stress on the variation of stable isotopes in plant leaf-waxes in different crown positions in a temperate deciduous forest along a tree species gradient with different abundance of European beech (Fagus sylvatica L.)

This project investigate the link between aboveground- and belowground diversity in a forest ecosystem. We determined the effects of the tree species composition on the biomass and composition of the soil microbial community using phospholipid fatty acid (PLFA) profiles. The correlation of PLFA-data from different seasons and soil depths with numerous site characteristics and plant traits should reveal the factors most driving the soil microbial community.
In a subproject we analysed the variation of stable isotopes in beech leaf-waxes from the lower and the upper crown along the tree gradient after a summer drought in 2006. Additionally we were able to measure stable isotopes from water samples of throughfall and soil water in this year collected by project B3. The results should give insight into the effect of water stress during prolonged droughts on the variation of stable isotopes in leaf-waxes of drought sensitive trees species like Fagus sylvatica.


Study methods

• Extraction of phospholipid fatty acids (PLFA) from soil samples
• Extraction of n-alkanes from plant samples
• Application of gas chromatography and mass spectrometry for the quantification and identification, and for the measurement of stable isotopes (δD, δ13C, δ18O)