The dependence of fungi on host and habitat is emphasized and the reti
culate pattern of the interactions explored. Habitat diversity, often
defined by the vascular plant element, vertebrate and invertebrate ass
ociations, and non-phanerogamic mutualisms are considered. The role of
man especially in changes in habitat availability is stressed. Intras
pecific variability is mentioned. The diversity of habitats is as much
a part of the Rio Convention as molecular, cellular and organismal va
riation.