The substrate is what the fruit-bodies are directly growing on (apart from those that occur among the remains of animal carcasses). For agarics that are growing on the ground and not obviously on larger pieces of wood, look carefully at what the fruit-body is attached to when picked to see if it is actually growing on litter or mulch (rather than the soil).

If fruit-bodies are growing on the trunks of tree ferns, do not choose any options for this feature because mycorrhizal agarics (which otherwise only grow on the ground) often grow on tree ferns trunks associated with living roots of other plants that grow in the trunks. If on tree ferns, look around to see if fruit-bodies are also growing elsewhere to decide on the correct choice for this feature.

Choose this state if: fruit-bodies are associated with decaying carcasses of vertebrate animals, including native animals (kangaroos and snakes) and introduced animals (cows and sheep).

Fruit-bodies are normally observed when the animal flesh has rotted away, and they occur among the remaining bones and hide. Fruit-bodies appear due to the stimulus of nitrogen compounds released from the decaying carcass. Species found in this habitat, such as Hebeloma aminophilum, are known as postputrefaction fungi, and will also often be stimulated to fruit by the application of nitrogen compounds such as urea to the forest floor ('ammonia fungi').

See: Suzuki, A., Fukiharu, T., Tanaka, C., Ohono, T. & Buchanan, P. (2003), Saprobic and ectomycorrhizal ammonia fungi in the Southern Hemisphere, New Zealand J. Bot. 41: 391-406.