Parameter Tree:
EARTH SCIENCE > BIOSPHERE > VEGETATION > TREE RINGS

Definition:
Tree Rings, also known as annual rings or growth rings, are a sheath of
cells appearing as one of a series of concentric rings in the
cross-section of a woody stem. Each ring is usually the result of a
single yearly growth flush starting in spring and ceasing in late summer.
 


Reference:
Allaby, M. 1998. A Dictionary of Ecology. Oxford University Press. Oxford, New
York.