Title: Slajd 1
1www.carbon14.pl
Mariusz Fogtman and Anna Pazdur Silesian
University of Technology Department of
Radioisotopes
2INTRODUCTION
Scientists can use the tree rings for
reconstructing past climate because trees are
good environmental indicators. They produce very
small rings during years of drought and large
rings during years of good growing conditions.
By counting the rings from the middle of the
trunk, and studying the width of the rings,
scientists can reconstruct an approximate
calendar of wet and dry years. Scientists assume
that the weather affected ancient tree ring
growth the same way it does today. Scientists can
also date the occurrence and frequency of fires
by finding scars that appear in the growth rings.
Additionally measurement of isotopic ratios e.g.
d2H, d13C, d18O and others in annual tree rings
by mass spectrometer allows to track the isotopic
ratios changes to determine the climate
conditions in the past.
3CHARACTERISTIC OF TREE COMPONENTS
Trees go through annual cycles of growth. Roots
are busy in the early spring and late fall.
Leaves and twigs grow in spring and the tree adds
wood all summer long.
http//www.na.fs.fed.us/spfo/pubs/uf/treeguidehtm/
chapter4.htm
4INSIDE THE TREE
Cross-section of the tree trunk.
5INSIDE THE TREE
Tree ring width Variability of tree ring width
and climatic conditions Seasonal patterns
Early wood Large, thick-walled cells
Late wood Small, densely-packed, thin-walled
cells Together an annual
growth ring Mean width of rings dependant on
tree species tree age
availability of stored food climate
(precipitation, temperature, humidity,
sunshine, windspeed, humidity) Trees
as filters and sources of palaeoclimatic data
6TREE SAMPLING
TREE SLICE SAMPLING
TREE CORE SAMPLING
Collection of the tree slice
Increment borer
Two kind of tree sampling for dendrochronology
measurement
Tree slice surface preparation by polishing
Choice of the suitable part of tree slice for
dendrochronology measurements.
Tree core
7TREE RINGS MEASUREMENT
Device for tree ring width measurement LINTAB in
Gliwice Tree Ring Laboratory Measurement
precision is 0,01 mm.
8TREE RINGS MEASUREMENT
Each tree should be measured at least in two
radiuses. The final results is mean from each
radius of adequate tree ring measurement.
9UNDER THE MICROSCOPE
Microscope view of pine (Pinus Sylvestris) slice.
This part shows annual tree growths close to tree
pith.
10UNDER THE MICROSCOPE
11UNDER THE MICROSCOPE
In some cases tree growths are very thin (e.g.
during the drought). In this picture annual
growths with very small width 0,3 0,8 mm are
shown.
12REGISTRATION OF MEASUREMENT DATA
TSAPWin Basic 1.15b Program for
registration tree measurement data.
13EXAMPLES OF DENDROCHRONOLOGY MEASUREMENT
This pine slice comes from Niepolomice Forest,
near Cracow.
14EXAMPLES OF DENDROCHRONOLOGY MEASUREMENT
This pine slice also comes from Niepolomice
Forest, see the similarity of dendrochronology
measurement on plots.
15CHRONOLOGY
For investigations of climate condition changes
in the past, on the basis of dendrochronology
measurement, the calendar scale must be
prepared. In this fact the tree rings from
different trees are compared for construction of
complete chronology. In many cases tree rings
width were correlated with dendrochronology
standard adequately for investigated tree
species. This correlation allows to match the
measurement of tree rings width to the
calendar years.
Different sources of dendrochronology material
Matching of tree rings width or indices
Chronology
16ISOTOPIC COMPOSITIONS IN TREES
Atmospheric CO2
d34S
d13C
Light
d15N
d18O
Precipitation
d18O
d2H
17PREPARATION OF SINGLE TREE RINGS
Tree slice was cut by small chisel
After that, wood sample is cut for small pieces
for chemical treatment
Combustion to CO2 for GPC measurement
Resin and dyes removes
Benzene production for LSC measurement
cellulose production for stable isotope
concentration measurement
Boiling samples in laboratory bath several hours
in 90ºC for removing of rest of chemical
mixture. Next samples are dried.
Chemical treatment in Soxlets columns. Wood is
in cotton bags. Wood samples are rinsed
in benzene/alcohol mixture (2/1 proportion)
18MEASUREMENT OF ISOTOPES RATIOS IN TREES
CO2
Benzene
Cellulose
GPC
LSC
MASS SPECTROMETER
AMS
d13C
d2H
d18O
d34S
d15N
D14C
19THE END
www.carbon14.pl