A- Ecological Habitat

Substrate Types:
saxicolous lichens: lichens living on calcareous and siliceous rocks, stones, also walls, cement, concrete, roofs and other man-made substrates.

saxicolous

terricolous lichens: lichens growing on the ground, on soil.

terricolous

epiphytic lichens: lichens living on the barks of trees; trunks, branches, twigs or bases, or on wood, timberwork etc

epiphytic

musicolous lichens: on mosses.

lichenicolous lichens: on the other lichens.

B- Lichens the "Pioneers"
Lichens are pioneer plants in ecological succession. They slowly deteriorate the rocks and stones by releasing substances through the substrate they live on. A thin soil layer forming on the rock becomes available for the mosses and other lichens. Than the remnants of these plants make the soil rich in organic matter, and provides higher plants to be able to live there.

C- Ecological Values of Lichens
- prevent soil erosion by holding the soil particles together with their fungal hyphae.
- provide deterioration of rocks by secreting secondary products "lichen acids".
- provide increase of organic matter in soil needed by higher plants.
- nesting place for some fauna members (eg. insects).
- food for some animals eating lichens (eg. reindeers eat Cladonia, Cetraria sp..).
- decoration material with their natural and rich appearance (especially in the Japanese gardens).

D- Ecosystem
Lichen communities are distributed worldwide from Arctic and Antarctic polar regions to deserts, in severe environmental conditions. For example, they can grow on bare rocks, on ice, in deserts and seas. Consolidated shingle beaches, where sufficiently old and stable, may have rich lichen floras. Montane regions with high elevations, sufficient sunlight and humidity, and clean air have rich lichen floras, as well.

E- Lichen Sociology
Lichen species may prefer living with each other or with several bryophytes, and they produce certain "associations". For example; Peltigera and Cladonia species living on tree-base trunks, or soil lichens form associations with mosses.

"Cladonia and mosses"

F- Number of Lichens
- about 20 000 lichen species have been discovered in the world.
- about 4000 lichen species have been recorded from the Mediterranean region where Turkey is included in.
- about 1000 species have been recorded so far in Turkey, thus "Turkish Lichen Flora" hasn't been completed, yet.