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(a)
(c)
(b)
Identical ring pattern
in both trees
(B) Dead tree
(A) Live tree
A
B
C
1930
1940
1950
1960
1970
1980
1990
2000
Identical ring pattern
in both trees
(C) Old house with wood support
(d)
Figure 9.16 Using trees to reconstruct climate change.
(a) The theoretical foundation of dendrochronology is that many trees
produce annual growth rings, with dark and light wood representing winter and summer seasons, respectively. (b) Using an increment
borer to core a tree. (c) A 4000-year-old bristlecone pine in the White Mountains of California. (d) The premise of cross dating is that
the tree ring record can be extended back in time by overlapping ring patterns from a sequence of trees. In this simplified diagram,
ring set A comes from a living tree, ring set B comes from a tree that recently died, and ring set C comes from wood that was used in
an old house. This particular record would permit climate reconstruction between about 1930 and the early 2000s.
