Meet jointPE – A long-term pot experiment of our SystemLink group

In this post, Kai Riess and Verena Rösch highlight a long-term pot experiment to evaluate the effects of anthropogenic stressors on native plants, soil organisms, and rhizosphere properties.

While taking a walk near Siebeldingen during the weekend, you may have noticed our more than 200 pots in the picturesque countryside near the Palatinate Forest. Only a few days ago, we started one of the central experimental setups of the Research Training Group SystemLink. In these long-term outdoor microcosms, we intend to evaluate varying levels of anthropogenic stress (fungicides and invasive species).

The outdoor microcosm setup (photo by SystemLink)

In order to create conditions as close to nature as possible, we dug up unpolluted floodplain soil to use in the microcosms. That was hard work! This soil containing natural microbial communities was mixed with ground sandstone and fertilizer. We added copper sulfate with concentrations up to 2 g/kg soil as a chemical stressor.

Digging up natural soil for the experiment (photo by SystemLink)

Finally, we installed measuring instruments and planted our three target plants. Himalayan balsam (Impatiens glandulifera) and Japanese knotweed (Fallopia japonica) are examples for invasive plant species in our area, while Common nettle (Urtica dioica) represents a native plant species in riparian habitats.

With this experiment, we are trying to answer several questions, such as:

  • What is the impact of anthropogenic stressors on biogeochemical cycling at the root-microorganism-soil interface?
  • Does Japanese knotweed accumulate nitrogen in the soil? Is nitrate leaching lower in these plants compared to the others?
  • How does copper affect the soil microbial community and plants over time?

We also aim to develop a pore-scale model to describe the distribution of mucilage in the rhizosphere.

Four PhD students from various disciplines (biology, chemistry, geography, physics, and modelling) will collect data in the scope of this experiment within the next years.

Join the pot experiment team (photo by SystemLink)

We are offering several bachelor’s and master’s theses, as well as jobs for students.

If you are not afraid of a challenge and would like to participate in this great experiment, please contact the SystemLink team.