Explain it like I'm five...

I am on about lichens here of late, mostly because they're one of the reliably interesting things this time of year (We're not quite to frogs and mole salamanders... a week or two, though, and they'll be more interesting. This is the mountains and it's cold. I checked out the usual soggy wets for egg masses and ... not yet. Soon, but not yet.) Anyway, lichens. The Internets (my resource for things, because even if it sucks, it is free) suggest that lichens grow "very slowly" or "sometimes very slowly and sometimes faster" which is fine as far as it goes but not... not really what I want. Most studies of lichen growth rates are on small round dot lichens up north, which is not all that helpful.

The internet does not have good information for how long it takes a rock greenshield lichen to get so big that I couldn't stand on it with both of my feet and still have lichen peeking out around the edges. (They totes get that big around here. See here: https://www.inaturalist.org/observations/9940170 and yes, I can see that that one is really two smaller lichens that have grown into each other with, if you want to be technical about it, two other, smaller ones on top that are also in the process of merging into the whole, here.) This is a big lichen, like easily 15 cm across. So... this lichen grows at what rate?

Because I was curious, I did some reading beyond Wikipedia and http://publications.aston.ac.uk/15210/1/Folios_lichen_growth_review_for_pdf.pdf -- this article was particularly interesting, but basically nobody out there is answering the questions I want answered in an 'explain it like I'm 5' sort of way, which are these.

1. How fast do rock greenshield lichens grow where I live?

2. How big, approximately, does a rock greenshield lichen have to be before it gets all fluffy in the middle?
   
   2a. Why do they get all fluffy in the middle? Are they old? Dying? Insane? Under attack by some other lichen due to having made a microhabitat at the center of themselves that favors colonization by something else? What is going on with that? It's an age/size related thing -- smaller ones do not do that fluffy business.

3. Do bigger lichens grow faster than smaller ones? (What does this mean? Does it mean "increases radius faster" or does it mean "increases surface area faster" or should this be a ratio of current size to starting size? What numbers are useful, here?)
4. How the hell do you measure lichen growth rate meaningfully? Digital pictures? Assume a round lichen and measure some diameters? Radii? I feel like overlaying digital pictures would be helpful. That might give an answer in pixels, but... yeah.
5. What is a good way to mark where your subject lichens are in the field so that you can find them again in another year? (This is especially important when basically huge swaths of your woods are covered in rather similar size & shape grey sandstone-y rocks that have lichens on them.)

I'm kind of curious about this. Maybe I should look into it.

Publicado el febrero 22, 2018 06:12 TARDE por whichchick