This is air layering propagation at work, where the mature tree or plant is cloned from a stem that is still attached to it.

Layering is a simple form of propagation which consists of bending a low branch or shoot down to soil level, wounding the shoot and then covering this portion with soil to encourage it to root.

This is due to the layer of air next to the ground being stationary ... Uno Ingard, "A Review of the Influence of Meteorological Conditions on Sound Propagation," Journal of the Acoustical Society of ...