AEBI 210 Lecture Notes - Litmus, Lichen, Crustose
8 Jan 2013
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Document Summary
Symbiosis between a fungus and a photobiont such as algae or cyanobacteria. Fungi can be uni- or multicellular, which have long filamentous hyphae strands. Fungal hyphae may obtain carbohydrates from the algal cells. Crustose is crust-like and grows flat against a structure. Foliose have leaf-like structures which are not tightly bound. Fruticose are free standing with a branching structure. Asexual reproduction occurs by way of fungal hyphae containing algal cells. Bud-like outgrowths develop on thallus and fall off to germinate. Lichens are tolerant of extreme desiccation, and can survive for long times. They produce lichen acids which weather rock, colonizing it and forming soil. Lichens with cyanobacteria can supply nitrogen to the ecosystem. Since lichens are sensitive to so2 pollution, they are an indicator of pollution. Lichens can be used as dyes (as in litmus paper) or eaten. Slow-growing lichens can be used to date surfaces they grow on (lichenometry)
