Presentation on theme: " 14 C 13 C 2H2H2H2H 18 O Mariusz Fogtman and Anna Pazdur Silesian University of Technology Department of Radioisotopes www.carbon14.pl."— Presentation transcript:
14 C 13 C 2H2H2H2H 18 O Mariusz Fogtman and Anna Pazdur Silesian University of Technology Department of Radioisotopes www.carbon14.pl
S cientists 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. d 2 H, d 13 C, d 18 O and others in annual tree rings by mass spectrometer allows to track the isotopic ratios changes to determine the climate conditions in the past. INTRODUCTION
CHARACTERISTIC 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
INSIDE THE TREE Cross-section of the tree trunk.
INSIDE 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, 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 sunshine, windspeed, humidity) Trees as filters and sources of palaeoclimatic data
TREE SAMPLING TREE SLICE SAMPLING Increment borer Collection of the tree slice Tree slice surface preparation by polishing Choice of the suitable part of tree slice for dendrochronology measurements. Tree core TREE CORE SAMPLING Two kind of tree sampling for dendrochronology measurement
TREE RINGS MEASUREMENT Device for tree ring width measurement LINTAB in Gliwice Tree Ring Laboratory Measurement precision is 0,01 mm.
Each tree should be measured at least in two radiuses. The final results is mean from each radius of adequate tree ring measurement. TREE RINGS MEASUREMENT
UNDER THE MICROSCOPE Microscope view of pine (Pinus Sylvestris) slice. This part shows annual tree growths close to tree pith. PithBark
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. PithBark UNDER THE MICROSCOPE
REGISTRATION OF MEASUREMENT DATA TSAPWin Basic 1.15b Program for registration tree measurement data.
EXAMPLES OF DENDROCHRONOLOGY MEASUREMENT This pine slice comes from Niepołomice Forest, near Cracow.
This pine slice also comes from Niepołomice Forest, see the similarity of dendrochronology measurement on plots. EXAMPLES OF DENDROCHRONOLOGY MEASUREMENT
CHRONOLOGY F or 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
ISOTOPIC COMPOSITIONS IN TREES Precipitation Atmospheric CO 2 Light 13 C 18 O 2H2H2H2H 15 N 34 S ‰ ‰ ‰ ‰ ‰
PREPARATION OF SINGLE TREE RINGS Tree slice was cut by small chisel After that, wood sample is cut for small pieces for chemical treatment Chemical treatment in Soxlet’s columns. Wood is in cotton bags. Wood samples are rinsed in benzene/alcohol mixture (2/1 proportion) Resin and dyes removes Boiling samples in laboratory bath several hours in 90ºC for removing of rest of chemical mixture. Next samples are dried. Combustion to CO 2 for GPC measurement Benzene production for LSC measurement cellulose production for stable isotope concentration measurement
MEASUREMENT OF ISOTOPES RATIOS IN TREES CO 2 Benzene Cellulose GPCLSC AMS 14 C 13 C 2H2H2H2H 34 S 18 O 15 N MASS SPECTROMETER
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