If stored bark or bark from fallen trees is used, the bark should be heated by soaking in warm water, or by steaming over a fire.
(stored bark or bark from fallen trees; is used; ) (the bark; should be heated; by soaking in warm water, or by steaming over a fire)
stored bark or bark from fallen trees the bark
is used should be heated
by soaking in warm water, or by steaming over a fire