Soil nutrient dynamics

Prof. Dr. Yvonne Oelmann, Tübingen

The objectives of SP05 are (i) to assess the resistance and recovery of soil microbial nutrient dynamics during and after a drought, respectively, (ii) to test the effect of plant diversity on the resistance and recovery of soil microbial nutrient dynamics and link this to plant nutrient dynamics (SP06), and (iii) to test the long-term effect of plant diversity on soil nutrient dynamics in soil as affected by extreme events.
We hypothesize that:
H1.1: The resistance of soil microbial nutrient dynamics is less pronounced as compared to the recovery. (WP1)
H1.2: The resistance and recovery of microbial nutrient dynamics are nutrient-specific. (WP1)
H1.3: The resistance and recovery of microbial nutrient dynamics are increased at high as compared to low plant diversity. (WP1)
H2.1: The microbial community reduces nutrient uptake and is prone to nutrient release during drought but rapidly takes up nutrients after a drought. (WP2)
H2.2: Particularly at high plant diversity, the nutrient dynamics of soil microorganisms and other organisms such as plants are complementary, i.e. asynchronous: plants are resistant to nutrient release during a drought, while soil microorganisms recover rapidly and take up nutrients after a drought. (WP2)
H3: Although the fluctuating abundance of legumes affects the stability of soil nutrient dynamics over time, plant diversity stabilizes nutrient dynamics in soil under mixtures with and without legumes against extreme events. (WP3)