Hmmmm....must not get the fungal partner round here....lots of lichen though...
i may not have presented that well.
all lichens, to be lichen, have a fungal part and one or more algal parts. (the fun-fact "• Lichenized fungi occur in 16 orders of ascomycetes, and five of these fungal orders have no free-living species. " is just saying that ~31% of all lichens have partners that cannot live without each other, and so ~69% of all lichens do have partners than can live apart. what are lichens
Lichens are made up of two, and some times three, different organisms from three different Kingdoms, which form a symbiotic relationship with each other for their mutual survival.
The dominant member is a ascomycetous fungus (Kingdom Fungi), which is capable of making it's own food. The fungus forms the visible portion of lichen inside of which, and protected by them, are cells of an algae (kingdom Protista) or some times cyanobacteria (Kingdom Monera), once known as blue-green algae. Some lichen can consist of all three organisms at once.
The algae provide nutrients, as they contain the pigment chlorophyll, which it uses during photosynthesis to produce carbohydrates the same way as green plants do. Thus the fungus obtains nutrients from the algae, the fungal tissue in turn provides shelter for the algae allowing it to grow in harsh conditions such as rock surfaces where it would otherwise be destroyed. ....
... prolly cuz we have a very damp climate....as to pollution being a factor....I dunno....I've seen it grow in some pretty nasty places....can't wait for summer...will have to remember to get some snaps of the more bizzare things in our woods round here.
looking a bit further i find lichens can & do live in deserts and inhospitable environs, contrary to what i thought and implied earlier.
while "moist environment" may be necessary for "activating" some of the lichens i am finding and that you have there, "moist environment" it seems is not necessary to find some
... Lichens can live on soil, woody debris, rocks, tree bark, tree leaves, other lichens, desert sand, animal bones, and rusty metal. For this reason they are nature's pioneers. Been first to colonise the most inhospitable places from there they begin the slow process of creating the foundation for other habitation.
How They survive ?
To assist their survival in such inhospitable conditions, lichens are able to shut down metabolically during periods of unfavourable conditions then with the appropriate amount of light and moisture, clean air, and freedom from competition, lichens will continue to grow. Most lichens grow very slowly, often less than a millimetre per year.
Another method that helps with there survival is that lichens can produce an arsenal of more than 500 unique biochemical compounds that serve to control light exposure, repel herbivores, kill attacking microbes, and discourage competition from plants.
the pollution bit i have found is very particular
) to specific species and their chemical analysis in a lab as well as growth habit and/or speed observed in the field. i don't know enough other than to make a general statement as i did. consult your local lichenologist or university extension service.
looking forward to your pics.
that is all. ... for now.
Edited by Turtle, 17 February 2012 - 02:17 AM.