12. Climate acts to synchronize growth rates at the
level of the cell, the tree, the forest and beyond.
13.
14. “ RINGS
IN THE BRANCHES OF
SAWED TREES SHOW
THE NUMBER OF YEARS
AND, ACCORDING TO THEIR
THICKNESS,
THE YEARS WHICH WERE
MORE OR LESS
DRY. ”
Leonardo da Vinci
16. THE PRINCIPLE OF LIMITING FACTORS
The rates of biological processes in trees, including the
formation of woody cells, are constrained by the primary
environmental variable that is most limiting.
22. THE PRINCIPLE OF CROSS-DATING
Matching pa erns in tree-ring widths or other ring characteristics
(such as ring density) among several trees allow the identification
of the exact year in which each ring was formed.
38. A “missing ring” is a term used to describe the phenomenon
where a tree does not form wood around its trunk during a
single growing season.
39. A “missing ring” is a term used to describe the phenomenon
where a tree does not form wood around its trunk during a
single growing season.
At the position where the tree-ring sample was collected!
66. Widespread drought caused narrow rings
to form across the southwest USA
during 1748 and 1750.
Source: Kurt Kipfmueller
67.
68. What kind of trees have rings that can be
dated?
• They have distinct and detectable rings.
• Their rings must be reliably annual.
• The formation of their rings must be
sensitive to environmental conditions.
• That sensitivity must cause the rings to
vary from year to year.
• Several trees must share common
pa erns in tree-ring width, wood
density or some other wood variable.
71. ‘Complacent’ tree-ring series:
• exhibit very li le year-to-year variation.
• grow in se ings where the limiting growth
factor doesn’t change much.
• are tough to cross-date.
75. ‘Complacent’ tree-ring series:
• exhibit very li le year-to-year variation.
• grow in se ings where the limiting growth
factor doesn’t change much.
• are tough to cross-date.
‘Sensitive’ tree-ring series:
• have wide and narrow rings that are
intermixed through time.
• Found in environments where the limiting
factor is highly variable year to year
• Matching ring pa erns across trees is
easier.
