Lichen as a dating tool Nudechatroullete

The total number of lichen species in the northern forest is unknown.

There are an estimated 13,500 to 17,000 species worldwide.

Once established, however, most grow slowly, with an annual rate measured in millimeters. They do secrete acids that will etch rock, but the amounts are tiny; they’re not trying to feed on their substrate.

Trees themselves can help since they can be reliably dated.Lichens are generally considered both algae and fungi.They have the green quality from algae, as well as the ability to grow without seeds from the decomposition of water (Marshall).Most lichens prefer to live on the sunny side of whatever it is they’re growing on, the better to photosynthesize.However Selva’s stubble lichens – think “beard stubble” for scale – are contrarians. Other lichens are easier to spot: the reindeer moss (which is not a moss, despite the name) common in spruce-fir forests and subbed for trees in model train setups; old man’s beard, which grows on trees and looks like lungwort, a big, broad-lobed lichen that turns bright green when wet; British soldiers, whose red tops that make them look like miniature matchsticks, grow from the forest floor.