A specific feature of TUMmesa is the LED-based light system, enabling flicker-free illumination and independent wave length-defined PAR control, including UV-A and B ranges. Low heat dissipation permits reduced ventilation and, as a consequence, hardly any vibrations, noise emission and air turbulence that could disturb the experiments. A wide range of ecological conditions can be generated, including manipulated CO2 and O3 concentrations. The experimental communities can be established in spacious planting containers, designed as balancing lysimeters and with a separate control of temperature, irrigation and fertilization in the soil compartments. Resource flux assessment is supported by online stable isotope analysis (12/13C, 14/15N, 16/18O, H/D) and labelling of organisms, soil and/or air compartments.