Presentation on theme: "The key to forest health."— Presentation transcript:
1The key to forest health. TROPICAL FUNGIThe key to forest health.
2HOW DOES A FUNGUS GROW?The living body of the fungus is a grayish, stringy mass called a mycelium (= the green plant of a rose bush).The fruiting body of the fungus is the mushroom (= the rose of a rose bush).The mushroom produces spores that result in new fungi.
3HOW DOES A FUNGUS OBTAIN NUTRITION? Fungi can be saprophytic, meaning that they feed on non-living materials. Their mycelia use chemicals to dissolve and absorb nutrients.Fungi can be parasitic, meaning that they feed on living materials.On plants (smuts, rusts)On animals (Histoplasma in human lungs)Fungi can also be mutualistic, living with other organisms.Lichens
4The mycelia of many species of fungi unite with the roots of forest trees. These mutualistic symbiotic mycorrhizal associations provide the fungus with photosynthesized products and the trees with chemically obtained nutrients. The mycelia grow so fast that they capture most of the nutrients.
8Fairy Ring (so called because people believe that fairies come out and dance in the circle) – Since the mushrooms (fruiting bodies) use a lot of nutrients, they tend to pop up around the periphery of the growing mycelium. The mycelium is consuming nutrients where it exists.
9Bracket Fungi, Belize. Remember, the brackets are the reproductive portion, and the body of the fungus is the mycelium that is in the dead limb.
20There is a whole group of mushrooms called stinkhorns due to their putrid smell. They emit putrescine (a polyamine precursor of spermidine, first found in decaying meat but now known to occur in almost all tissues and in some bacterial cultures; a crystalline, slightly poisonous, colorless, foul-smelling ptomaine [a product of bacterial or protein metabolism] produced by the decarboxylation of ornithine, especially in decaying animal tissue) and cadaverine (a foul-smelling nitrogenous base, pentamethylenediamine, produced by decarboxylation of lysine). It is produced in decaying protein material by the action of bacteria, particularly species of Vibrio. WHAT YOU NEED TO KNOW: Stinkhorns produce putrescine and cadaverine, and both have a horrible odor associated with decaying flesh. Yuk!
21What is the selective advantage of emitting putrescine and cadaverine? To attract flies, which are the agent for the distribution of their spores.
22Lacey Stinkhorn, Dictophora, Hato El Cedral, Apure, Venezuela Lacey Stinkhorn, Dictophora, Hato El Cedral, Apure, Venezuela. Its putrid smell attracts flies that spread the spores, as do all stinkhorns.
23Bridal Veil Stinkhorn, Dictyophora indusiata, Cockscomb Bridal Veil Stinkhorn, Dictyophora indusiata, Cockscomb. The vail is technically called an indusium (outgrowth).
25Yet another stickhorn is Clathrus crispus Yet another stickhorn is Clathrus crispus. This one appeared overnight at Chaa Creek during a heavy rain storm in August, These mushrooms deteriorate quickly, lasting less than one day. Note the flies.
28This fungus has dissolved all of the leaf but the ribs and edges (found in Cockscomb).
29Cordyceps – ONE OF THE UNIQUE FUNGI OF THE TROPICS. Cordyceps is a tropical fungus that grows in the ground.An invertebrate (tarantula, insect, etc.) brushes against the mushroom and spores stick to its exoskeleton.Spores begin to grow, entering openings in the exoskeleton.As the mycelium grows, the carrier can’t resist the urge to climb up vegetation.At some point, the fungus kills the carrier, which turns white with fungal growth.
30MORE ON Cordyceps . . . The fungus produces spores. The dead carrier ruptures.The spores blow away in the breeze.This whole system seems to have evolved to help the dispersal of the Cordyceps spores.
31LICHENS ARE . . .Lichens are a mutualistic symbiotic association of a fungus and algae or cyanobacteria.The fungus gets food from the photosynthesizing algal cells.The algae get moisture and a place to live from the fungus.Remember: “An alga took a likin’ to a fungus.”
32TYPES OF LICHENSFoliose: leaf-like lichen (curly lobes and margins)
33Types of Lichens (cont.) Crustose: crust-like lichen (adhere tightly to the surface; rather coarse to the touch)
34Types of Lichens (cont.) Fruticose: shrub-like lichen; In fact, they belong to the genus Usnea (the scientific name of Spanish moss is Tillandsia usneoides – the last word meaning “like Usnea”).
35Galápagos guide, Phillipi Degel, wearing an Usnea beard.