Investigating anthropogenic disturbance across a hierarchical progression of ecological system complexities – insights from low-frequency magnetic fields

The multiple feedback mechanisms involved in complex systems modulate the propagation of stresses through the hierarchical progression of ecological systems, yielding adaptive dynamics and unpredictable outcomes, ultimately making its study a highly non-trivial task. This is especially true when the mechanistic understanding of stress-response relationships is still rudimentary, as in the case of oscillating magnetic field (MF) interactions with ecological systems, where the responses may depend on frequency, intensity, phase and time of exposure. With a view to shedding light on these interactions, we focused on natural low frequency MFs potentially interfered by anthropogenic MFs, i.e. the first mode of the Schumann resonances (7.83 Hz), studying the effects of varying intensities and exposure times on multiple levels of ecological organization, purposefully choosing the analytical targets in relation to system properties. In particular, effects were investigated at the level of organism, focusing on animal behavioral ecology and plant ecophysiology and development, of population, analyzing seed recruitment and germination kinetics, and of ecosystem, investigating organic matter decomposition by soil microbial community. System responses were studied under controlled conditions in order to highlight potentially small effects, using exposure devices and settings purposefully developed and chosen according to finite element modelling analyses. Preliminary results highlight the presence of invariant responses across different levels of organization, with MF eliciting clearer dynamics to the varying field intensity (7.5 µT, 15 µT, 30 µT) at short exposure times (15’ in respect to 30’ and 60’), especially at the population and ecosystem levels. Considering the interaction between the artificial and the natural MFs, differing in field intensities and phases, findings can be explained in terms of intermediate disturbance. Overall, our research demonstrates the coupling between low frequency magnetic fields and the functioning of ecological systems at different levels of complexity, with responses modulated by interfering anthropogenic fields.