humus group - Territorio e Sistemi agro-forestali - Università degli ...

Humic component on a palm hand.
This scrap of OH horizon is mostly
composed of minute animal
(arthropod and enchytraeid)
droppings. It also corresponds to a
sample of zoogenically transformed
material.
Non-zoogenically transformed material.
Dry or cold climate, acidity,
unpalatibility of the substrate,
introduction of new and unadapted
species (here the case of an organic
topsoil in an artificial stand of Pinus
radiata in substitution of a natural
Quercus ilex forest) lags behind the
arrival of pedofauna. The
decomposition of the organic substrate
is essentially due to fungal attack.