Presentation Lichens

8/2/2019 Presentation Lichens

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Group 3

Debby Masteriana(4113111008)

Leni Anggraini(4113111026)

Mawaddah Nasution (4113312010)Ummi Khairunisa(411331209)

Yerni Silalahi (4113312016)

Yohannes (4113111083)


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LICHENS


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Why study lichens?

They grow just abouteverywhere

They tell us about the health

of our environment

They are very useful; - asrecyclers of nutrients,providing homes for insects,

humans extract dyes fromthem, eat them, use them asingredients in drugs andcosmetics


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What are lichens?

Unlike trees, grasses and flowers, lichens arenot a single plant

Composite Organisms created by arelationship between fungus and algae. Thefungus provides the body in which the alga canlive protected from light and drought. The algamakes the food for the fungus.

They are actually composed of two organismsliving together in a symbiotic relationship


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Grow on walls, rocks, tree bark, and otherplaces where neither fungus nor algaecould exist alone.

They grow very slowly.

They can withstand extreme heat and cold(but not smoke or fumes).


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Types

Leafy (foliose)

There are about 30,000 species of lichen worldwide, covering8% of the land surface. There are 3 main types

Shrubby (fruticose)

Crusty (crustose)


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Crustose (Crusty) Lichen:

Grows flat or may be embedded in thebark or rock surface.

The entire undersurface of this type isattached.


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Some Crustose Lichens

Caloplaca saxicola(Medlin)

Xanthoria elegans(Medlin)

Rhizocarpongeographicu

m(map lichen)

(Medlin)


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Foliose (leaf-like) Lichen:

Attached in spots with marginsor ridges that are often lobedand free. They curl up off of thesurface from which they grow,and look like crumbled leaves.

This type is attached to the

surface by many root-likethreads.


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Some Foliose Lichens

Cetraria arenaria,Medlin

Pulmonaria lobata, Medlin

Parmelia sulcata, Medlin Peltigera canina, Medlin


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Fruticose (treelike or shrubby)Lichen

Like a branched plant.

They grow upright or hang from the

surface from which they grow and areonly attached to the surface at thebase.


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Some Fruticose Lichens

Cladina rangiferina,Brodo

Cladina stellaris, Medlin

Usnea hirta, Medlin Teloschisteschr so hthalmus


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Squamulose

Similar to Crustose, but with Raised Edges which can be Folded or Lobe-

Like.


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Lichen internal structure

Lichens are natures biological monitors of pollution

and air qualityThalli act like spongesSome species more sensitive to pollutionWhich species are present can indicate air qualityMost resistant species can also be analyzed forpollutants, including bioaccumulation of heavymetals and radioactive isotopes


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Lichens and air quality

Lichens are very sensitive to sulphur dioxide(SO2) pollution in the air from industry andburning fossil fuels, especially coal

They absorb it dissolved in water

It destroys the chlorophyll in the algaepreventing it from photosynthesising and killing

the lichen.

Levels have fallen since the 1970s


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Nitrogen pollutants

Nitrogen compoundsfrom traffic on roadsand from intensive

farming (fertilisers)have become majorpollutants

Town and countryareas can be affected


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Bio-indicators

Lichens are widely used as environmentalor bio-indicators

If the air is clean, shrubby, hairy and leafylichens become abundant

If the air is polluted more tolerant crustylichens are present

In extreme cases of high pollution, theremay be no lichens at all (lichen deserts)


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Sexual Reproduction in Lichens

* Only the fungal partner undergoes sexual reproduction

* In the ascomycetous (i.e. most) lichens, ascospores areformed in sacs called asci, mixed with paraphyses to form ahymenium.

* Asci can be arranged on an open or convex or concave disk,when it is called an APOTHECIUM, or in an immersed, urn-shaped PERITHECIUM.


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Asexual reproduction in lichens

* Fragmentation of thallus when dry and brittle

* Detachment of isidia

* Loose dusty masses of soredia

* Pycnidia

A. Soredia burstingthrough thallus ofLobaria

B.External view ofsorediate mass

Pycnidium of Lecanora


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Human Uses of Lichens* Brown, purple and red fabric dyes (e.g. Scottish tweeds

and tartans)

* Indicators and stains (e.g. litmus and orcein)

* Emergency foods, e.g. rock tripe (Umbilicaria)

* Part of the daily diet, e.g. Lecanora esculenta(manna?)in Iran, flour from Cetraria islandica(Iceland moss) inScandinavian ships biscuits, Inuit nirukkaq - partlydigested lichens from caribou & muskox stomachs in winter

* Commercial production of sugar in Russia, WWII

* Iwatake (Umbilicaria esculanta) as delicacy in Japan

* Food additive io retard spoilage


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More uses of lichens - medicine,embalming and perfumery (see

Richardson for details)

* Many lichen extracts are inhibitory to the growth ofGram-positive bacteria

* Some are also effective against Mycobacteriumtuberculosus

*Oakmoss (Evernia prunastri) and Treemoss(Pseudoevernia furfuracea) are used in Europe to make

fixatives for perfumes and soaps.

* The antibiotic properties of lichens were exploited bythe ancient Egyptians in their embalming procedures


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Result Observation


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Thank Youfor

Your Attention

:D

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Presentation Lichens