When vegetation yielded, the forces of the wind and the water managed to devastate the sensitive areas. If there are pools of water on the lime flat rocks in early summer, jelly lichens grow on the flat rocks. If the ground is not used for pasturage, the flat rocks will be colonized again. First come the cushion-formed Rhytidiadelphus triquetrus and Schistidium apocarpum. They are plants from the Arctic steppe flora with species like Artemisia oelandica, Shrubby cinquefoil, Thamnolia vermiculans, and Hoary Rock-rose.
Some lime stones moulder away and form decomposition soil.
In the decomposition soil we find the Hoary Rock-rose heath. Incidentally it is seductive to imagine that the Great Alvar always has been outlying land for man, an impediment as the term for unusable land goes. But this is not altogether correct. A considerable number of ancient monuments point out that man has resided and lived on the alvar several thousand years ago, at any rate where layers of moraine soil have accumulated. Some 50 farms or smaller villages from the Iron Age are known on the Great Alvar.