Relation between seismic noise levels and soil fauna

Human activities often impact the sensory environment of organisms. Wind
energy turbines are a fast-growing potential source of anthropogenic
vibrational noise that can affect soil animals sensitive to vibrations and
thereby alter soil community functioning. Larger soil animals, such as
earthworms (macrofauna, > 1 cm in size), are
particularly likely to be impacted by the low-frequency turbine waves that
can travel through soils over large distances. Here we examine the effect
of wind turbine-induced vibrational noise on the abundance of soil
animals. We measured vibrational noise generated by seven different
turbines located in organically-farmed crop fields in the Netherlands.
Vibratory noise levels dropped by an average of 23 ± 7
dB over a distance of 200 m away from the wind turbines.
Earthworm abundance showed a strong decrease with increasing vibratory
noise. When comparing the nearest sampling points in proximity of the wind
energy turbines with the points furthest away, abundance dropped on
average by 40% across all seven fields. The abundance of small-sized soil
animals (mesofauna, < 10 mm in size) differed between crop fields,
but was not related to local noise levels. Our results suggest that
anthropogenic vibratory noise levels can impact larger soil fauna, which
has important consequences for soil functioning. Earthworms, for instance,
are considered to be crucial ecosystem engineers and an impact on their
abundance, survival and reproduction may have knock-on effects on
important processes such as water filtration, nutrient cycling and carbon
sequestration.