DOM stability

Prof. Dr. Gerd Gleixner, Jena
Dr. Markus Lange, Jena

The general goal of this subproject is to investigate how plant diversity affects the stability of the interactions between plants, soil organisms, and soil organic matter, and thereby to gain a better understanding of biodiversity effects on ecosystem processes. On the one hand, we will focus on temporal aspects like “when” is exudation and decomposition happening and how is this varying between years, and, on the other hand, we will focus on spatial aspects like various soils depth to explore “where” can we observe higher variability and how is this stabilised by plant diversity. Therefore, the molecular DOM composition, which holds the molecular markers to analyse the different temporal and spatial aspects, will be investigated along the plant diversity gradients over several years accompanied with temporally highly-resolved measurements over a growing season. In addition, we will investigate how plant diversity stabilises the long-term dynamics of DOM and soil organic matter concentrations using the unique datasets of the Jena Experiment. The proposed project consists of three work packages, which pursue the following scientific objectives:

  1. Assessing the temporal stability of the soil exo-meta-metabolome in relation to plant diversity to characterise biochemical plant-microorganism-soil interactions (WP1).
  2. Exploring how the short-term effects of an extreme event (hot drought) on the plant carbon allocation to soil, the carbon-nutrient-trading between plant- and the soil microbial communities, as well as the soil exo-meta-metabolome are stabilised by plant diversity (WP2).
  3. Evaluating the long-term stability relationship between belowground activity and plant diversity on the basis of the time series of soil organic matter and DOM concentrations, which will allow to cover the spatial aspects of the stability (WP3).
    Work packages WP1 and WP2 of this subproject will use cutting-edge techniques, non-targeted ultrahigh resolution mass spectrometric approach (FTMS) and isotope labelling to investigate the diversity–stability relationship. WP3 will analyse unique time series to investigate the plant diversity–stability relationship in the long-term.