for information on my work with plant, tree and soil recording / research see;
moss listening (working title)
I use various microphones and listening devices for these types of recording, with c-series contact mics and d-series hydrophones an important element, alongside JrF adapted geophones.
There are several adaptations that I use with the c-series mics, for picking up sounds inside trees, ferns, moss, mycelium networks and other plants.