Resilience…a word we heard often in the last year, at least here in Italy…
Generally speaking, resilience is “the capacity of a system to cope with a change”. This term is used in different fields. In ecology, resilience is the capacity of an ecosystem or an organism to respond to a perturbation or disturbance by resisting damage and/or recovering, more or less quickly, after it.
Lichens can be quite resilient, and Cladonias are no less than the others.
I have recently met a singular case of resilient Cladonia during an inspection in a very degradated grassland in the Ticino river valley. In that area, grasslands are encroached by the invasive tree Robinia pseudoacacia, and soil is frequently disturbed by the passage of quadrupeds…and bipeds as well.
It can often happen to find cracked patches of Cladonias, especially of primary thalli of C. foliacea, C. polycarpoides or C. cariosa, as a result of heavy trampling. Sometimes, cushions of primary squamules are overturned, quite like old tortoises capsized on their shells, but, unlike tortoises, Cladonias are unable to regain their original position.
What happens then?
Obviously, the downturned part degradates and squamules die, because they are no longer reached by sunlight. But, if surrounding environmental conditions remain favorable, the former basal part, which is now placed on the top, can recover…and start producing new squamules!
This is what I found in some old, overturned cushions of Cladonia polycarpoides: the downturned part was blackened and dead, but the upturned part was developing new, tiny squamules, and would soon regain its former appearance.
Cladonia…uh…finds a way.
A cracked patch of Cladonia polycarpoides…
…with the old squamules now dead or dying on the downturned upper side of the cushion…
…and new, tiny squamules developing on the upturned downside.
Cladoniarium 