A collaborative experimental study will be established in April/May 2019 connecting two iDiv platforms - Ecotron and AquaDiva.
The envisaged experiment directly addresses the primary aims in AquaDivatowards understanding the links between surface and subsurface, especially how organisms inhabiting the subsurface reflect and influence their physical, ecological, and geochemical environment, and affect water and matter transition. In 6 of the 24 EcoUnits, we will investigate these questions in the light of climate change, particularly extreme weather events (drought/heavy rainfalls).
The key questions in EcoXtremesare:
- How are carbon, soil water, and gas fluxes altered under predicted climate impacts of increasing weather extremes?
- How do these contrasting drought/heavy precipitation events alter the transport mechanisms of organic matter (POM, DOM), nutrients, microorganisms, incl. viruses, inorganic particles and colloids through the soil column?
- Do we see differences in microbial activities and decomposition rates?
- Can we identify insect-induced “shortcuts” in nutrient cycling and spatial-temporal bypass flows of water and solutes connecting the soil surface and deeper soil layers?
- Can herbivory on dominant plant species exacerbate climate impacts by disrupting surface/subsurface linkages? For example, by decreasing plant exudation and transpiration rates, changing nutrient availabilities, and decreasing transportation routes by lower root densities?
Broadly, our experimental design will allow us to disentangle carbon, nutrients, microorganisms, and water transport mechanisms across two different factors: (A) precipitation (extreme vs. average) and (B) herbivory (with vs. without). Furthermore, this study will be the first iDiv Ecotron experiment in which intact and undisturbed soil monoliths are excavated using lysimeters.