Lichen-plant interactions

Figures & data

Table 1. Effects of physical and chemical factors related to the lichen colonization on/near land plants and, for comparison, on rocks. °,general pattern; *,exception to the general pattern; #,information based on single/few investigations; n.i., non-investigated; -,the involvement of this factor is not possible; […], notes.

	Effects of lichens on …
	… land-plants used as growth substrates			… land-plants being lichen neighbors on soil	… rocks
	- bryophytes	- vascular plants
Lichen factors	(muscicolous lichens)	(foliicolous l.)	(corticolous l.)	(terricolous l.)	(saxicolous l.)
Hyphal penetration and organization within the substrate	° no effects * except in the case of some lichen species behaving as parasites	[no penetration] * except in the case of some species of Strigula possibly living as semi-parasites	° endophloematic thalli: suberification of cork cells ° epiphloematic thalli: no effects * except in the case of Ochrolechia frigida (destruction of the penetrated tissues) and of Evernia prunastri (injection of allelopathic metabolites within the xylem vessels of oaks)	–	° physical disaggregation at the lichen-rock interface
Thallus expansion/contraction according to the hydration state	n.i.	n.i.	# periderm arching	# physical inhibition of seedling establishment	° mechanical defoliation
Interference on microclimatic conditions	# light interception causing moss death	# light interception causing leaf acclimatation (e.g., higher chlorophyll contents)	# light interception causing bark acclimatation (lower chlorophyll a/b ratio)	n.i.	° modifications of e.g., moisture supporting rock deterioration
Physical support to other organisms	n.i.	n.i.	° pathogenic insects, epiphytic plants, non-lichenized fungi	n.i.	° non-lichenized fungi and other rock-inhabiting microorganisms
Enzymatic processes	# hyphal penetration through the cell walls (β-1,4-glucanase)	n.i.	# thallus attachment (laccases); cell wall decomposition (β-1,4-glucanase and polygalacturonase)	n.i.	# dissolution of carbonates (carbonic anhydrase)
Secretion of secondary metabolites	° allelopathic inhibition of germination and growth assessed in vitro, but studies are needed in natural settings	[ poorness or absence of secondary metabolites ]	# allelopathic effects of Evernia prunastri on oaks (defoliation, decrease in vigor)	° allelopathic inhibition of germination and growth assessed in vitro, but not supported by studies in natural settings ° allelopathic effects on mycorrhizal fungi assessed in vitro and in the field	° chemical deterioration of minerals

Table 2. Effects of plant- and, for comparison, of rock-related factors on lichens. °,general pattern; *,exception to the general pattern; #,information based on single/few investigations; n.i., non investigated; -,the involvement of this factor is not possible.

	Effects of plants …				Effects of rocks on …
	… used as growth substrates on …			… being neighbors on soil on
Plant/rock factors	… muscicolous lichens	… foliicolous l.	… corticolous l.	… terricolous l.	… saxicolous l.
Physical and chemical surface properties	n.i. * but some species display specificity to their phorophyte	° no effect * but in some cases a slight community differentiation has been related to the surface structure and longevity of leaves	° influence on the community composition of bark properties, as texture, water holding capacity and pH	–	° influence on the community composition of rock properties, as surface roughness, internal porosity and mineral composition
Release of inorganic compounds	n.i.	n.i.	° contribution to the lichen mineral nutrition of ion leaching from the plant substrate	n.i.	° contribution to the lichen mineral nutrition of ion leaching from the plant substrate
Release of organic compounds	n.i.	n.i.	# allelopathic inhibition of lichen propagules and photobionts by bark-derived metabolites	n.i.	–