The lichen coverage in a specified area should be a good indicator of the level of air quality. Tardigrades are macroinvertebrates living in and on lichens. The diversity of the tardigrade species on the lichens will be used to develop another level for bioindication of air quality. Introduction Lichens are small, nondescript, often overlooked organisms. Once we notice them growing on the surfaces of trees, rocks, up the sides of buildings, and in mossy carpets in our forests, we cannot fail to admire the way in which they color our world.
Lichens are actually two organisms existing in a symbiotic relationship know as mutalism.
Lichens are typically composed of a green algae and a fungus. Lichens are classified based on the fungal component. Lichens appear in a wide variety of habitats because they can tolerate, and in fact thrive, under difficult environmental conditions. The alga manufactures and provides itself and the fungus with carbohydrates and some vitamins. Some blue-green algae can even fix nitrogen from the air.