Recap: I clear out overgrown graves in my local cemetery. I did a post a few days ago about why you should NEVER try to clean a gravestone without training.
In this post I went a little hard on lichen’s effect on a gravestone.
Link:Gravestone Safety 101: DON’T
Several commenters rightfully rebuked my claim that lichen is a dick. In my effort to be concise, I shortened the sentence too much. It is time for me to come back and add the appropriate addendum.
I originally called it a “plant-fungus” hybrid, because I thought that algae fell under plants. I’m not sure if that’s correct anymore.
Lichen is one of the few living creatures that turn a barren landscape into an ecosystem. They break down rock to make it habitable for other bio life to come in after it.
The lichen in this picture is doing an amazing thing, that will allow for future life to flourish. It’s also really cool how lichen spreads out and changes different colors.
Layperson’s analogy: Because the lichen are munching on the stone, they basically have their little fungal/algae teeth sunk into it.
Try to imagine putting a piece of steak in your mouth and clenching down on it. When someone tries to pry the steak from your teeth, it tears. This is what will happen if you try to brush lichen off of a stone.
You won’t SEE the damage, but it’s there, and it will weaken the stone (which is not good for historical preservation).
However, if this WASN’T a headstone, this would be a really good thing! This lichen is just having lunch, and all other bio life will come after it! But this is a gravestone, so that’s not exactly ideal…
Lichen is a bro in most situations. Just not a graveyard lol.
I had two sources.
1.) An amazing, layperson-friendly article that talked about how lichen broke down rock. But then it disappeared??
Link: https://lisbdnet.com/how-does-lichen-break-down-rock/
.
2.) An overview of lichen from PennState University
Link: https://extension.psu.edu/lichen-in-the-garden
As a side note: while it includes an overview of “how to remove lichen from stone,” keep in mind that there is a difference between a garden statue and a headstone. The headstone might be more delicate.