DENDROLOGY

Detailed explanation-1: –Lichens are called pioneers because the rock and ash producing soil will begin to be depleted. They can survive because they live in a relationship between a fungus and an algae that is mutualistic. Other species, bacteria, fungi, various grasses, etc., will emerge after these lichens have completed their job.

Detailed explanation-2: -A crustose lichen that grows on rock is called a saxicolous lichen. Crustose lichens that grow on the rock are epilithic, and those that grow immersed inside rock, growing between the crystals with only their fruiting bodies exposed to the air, are called endolithic lichens.

Detailed explanation-3: -Growth rates and specific thallus structures One of the most abundant saxicolous lichens is Rhizocarpon geographicum (Fig. 2.3. 1B, yellow), a frequent pioneer colonizer of newly exposed rock surfaces [10].