Environment and some features of 300- year-old larch V. - PowerPoint PPT Presentation

Environment and some features of 300- year-old larch V. Sapozhnikova, 1 B. Ageev,1 Yu. Ponomarev,1 D. Savchuk 2 1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Sciences 634021, Russia, Tomsk, Academician Zuev Square, 1 sapo@asd.iao.ru ,ageev@asd.iao.ru, yupon@iao.ru, 2 Institute of Monitoring of Climatic and Ecological Systems of Siberian Branch of the Russian Academy of Sciences, 634055 Russia, Tomsk, Academichesky prospekt, 10/3 savchuk@imces.ru

R. O. Teskey, A. Saveyn, K. Steppe and M. A. McGuire (2008) 2 “ Origin, fate and significance of CO2 in tree stems”, New Phytologist , 177 : 17–32 (d)- xylem sap (c)- xylem ray cells gas-analyzer corticular photosynthesis (b) - cambium (a) - inner bark Fig. 1 Schematic of important sources and sinks of CO 2 inside a stem segment of a tree: 1) diffusion of CO 2 out of the stem, 2) fixation of CO 2 3) CO 2 diffusing into the transpiration stream

3 The aim of this work is: to show that an analysis of variations in CO2 and H2O extracted under vacuum from tree rings in discs enables present views about CO2 and H2O functions in tree life to be extended and their association with climate changes and plant growth trends under changing environmental conditions to be understood .

Block-diagram of a photoacoustic laser spectrometer 4 • Waveguide CO 2 laser (1) [1], • photoacoustic cell (2), • microphone cell with homemade plane capacitor microphone (3), • photodetector (4), • electric signal measuring and recording system (5), • computer (6), • pump (7), • CO 2 /N 2 reference mixture (8). The system was pre-calibrated with a known amount of CO 2 , • exposure chambers (9). Fig.1.Block-diagram of a laser spectrometer

5 Our experimental system and procedure for investigations into CO2 and H2O in disc tree CO2+H2O rings are described elsewhere . The CO2 and H2O CO2 H2O P(20) P(16) R(20) content in samples vacuum-extracted from tree Absorption coefficient H2O, Km-1 Absorption coefficient CO2,Km-1 2,5 P(14) 2 rings was measured by a laser photoacoustic gas 2,0 H2O analyzer with a sealed-off waveguide CO2 laser using high-frequency excitation. The 1,5 0 measurements were performed in four tunable 1,0 CO2 laser lines: 10 P (20, 16, 14) coinciding with -2 CO2 absorption lines and 10 R (20) coinciding 0,5 with CO2 and water vapor absorption lines 0,0 (CO2+H2O). -4 1700 gas samples of Siberian stone pine discs, 940 950 960 970 980 Scots pine discs, Siberian spruce discs from cm-1 Tomsk and Altay Mountains were investigated. All tree discs were stored under laboratory conditions before measurements. Thus the wood material can be considered room-dried. Fig.2.CO2 waveguide laser lines An isotope analysis of carbon of desorbed CO2 and H2O water vapour spectrum in a few annual rings was made (63 samples). The carbon isotope composition of atmospheric CO2 is known to be, on average, δ 13C, (‰) = – 8.07 ‰, with leaves and tree wood being characterized by a lower carbon isotope composition (from – 20 ‰ to – 30 ‰ .)

Experiment 1 6 Fig.3. CO2 and (CO2+H2O) variations in disc tree rings of the Siberian stone pine (rel. units). CO2 rise! Cyclicity, CO2, ppm Fig.4. CO2 content in tree rings and annual ring width

Is there a climatic response of CO2 and H2O tree ring distributions? 7 Fig.5. Spectral density of the CO2 and (CO2+H2O) content for a 95 % confidence interval. Fig.6. Four-year components of wavelet transform for CO2 content (1), signal (H2O+CO2) ( 2, left vertical axis), and precipitation amount during dormant period ( 3, right vertical axis) A wavelet analysis, high-resolution spectral and cross-spectral analyses and digital time series filtration procedure were used for an annual CO2 and H2O distribution analysis relating to Siberian stone pine disc tree rings. Our first step was to look at the existence of climatic signal in our results.

8 Correlation coefficients R R, CO2 – precipitation (dormancy period) - 0,4 4-year period R, CO2 – temperatures (vegetation period) - 0,43 variations > 5 years R , width – precipitation (vegetation period) R=0.26 (variations ≤ 5 years), R=0.27 (4 year variations)

Experiment 2 9 1960 4000 3,0 Fig. 7 . Annual 3500 2,5 variations of the tree 2 1 Disc CO2, ppm (1) 3000 ring CO 2 content and 2,0 width in Scots pine 2500 Width, mm(2) 1,5 disc No. 6. (Pinus 2000 sylvestris L.) 1,0 1500 1000 0,5 2 1 500 0,0 1920 1940 1960 1980 2000 Year 4-year cycles 1960 CO2, ppm 8000 4,0 Width , mm (2) 1 2 1960 Disc CO2 , ppm (1) 3,5 6000 3,0 Fig.8 . Annual 2 variations of the 2,5 4000 tree ring CO2 2,0 content and width 1,5 2000 in Scots pine disc 1,0 1 No. 12. 0 0,5 1900 1920 1940 1960 1980 2000 2020 Year

10 Experiment and Result 3 Fig. 9. Annual variations in the CO2 content in tree rings of the Siberian stone pine disc from Seminsky Range ( 1650 m above sea level, Altai Republic, Altai Mountains). 1000 Fig.10. Annual variations in the 1961 1944 1987 CO2 content in tree rings 800 of the larch disc (village Chernorud, CO2, ppm 600 Lake Baikal). ( Priol’khonie, where Chernorud is situated, is the driest area 400 near Lake Baikal.) 200 There is a distinct tendency to a decrease in the CO2 content in tree rings 0 1940 1960 1980 2000 with age. Year

Delta 13C cellulose Delta 13C CO2 -23,0 -22 11 Experiment and Result 4 -23,5 -24 -24,0 -26 -24,5 -28 -25,0 -30 -25,5 Cellulose -32 -26,0 -34 -26,5 1750 1800 1850 1900 1950 2000 Fig.12. Comparison of the variations in the carbon isotope year composition of desorbed CO2 with δ 13 С of cellulose [ Hilasvuori,E. Dissertation, https://helda.helsinki.fi/bitstream/handle/10138/25679/environm.pdf?sequence=1 ]. Fig.11. Annual variations in the carbon isotope composition of CO2. Fig 14. Comparison of the carbon isotope composition of desorbed CO2 with δ 13 С in the atmosphere [ Francey R.J., Allison C.E., Etheridge D.M., Trudinger C.M., Enting I.J., Leuenberger M., Langenfelds R.L., Michel E., and Steele L.P. 1999. „1000-year high precision record of δ 13C in atmospheric CO2” T ellus (1999), 51B, 170–193 ]. Fig.13. Annual CO2 and carbon isotope composition in a larch disc.

12 0,18 Photoacoustic H2O, CO2 signals, rel.units 0,16 H2O 0,14 0,12 0,10 0,08 0,06 CO2 0,04 1700 1750 1800 1850 1900 1950 2000 2050 Year Fig.15. Annual variations in photoacoustic signals in laser lines (results smoothed out by a 11- year running average).

13 Fig.8. Superposition of long-term Fig.9. Amplitude spectrum of larch tree cyclicity on short-term cycles of ring CO2. the annual CO2 distribution in the disc tree rings of a 300-year larch. CO2 rise!

Effect of climatic factors on Larch CO2 14 PRECIPITATION TEMPERATURE temperature by -0,37 of April Precipitation of dormancy by 0,56 period ( November-March ) temperature by 0,39 of August The step-by-step increase of the moving lag (by 11-year) rises the coefficient of correlation at the same sign.

Conclusions 15 • The results obtained from investigations into the vacuum-extracted CO2 and H2O content in larch tree disc rings have shown that a considerable portion of these substances is stored in annual ring wood, i.e., in tree stems. As stem CO2 originates from respiring cells in tree stems and roots , CO2 rise is likely to be due to an increase in cell respiration. Our measurements show that this is a cyclic process, with the main cycle being a 4-year period modulated by long-term cycles. • A comparison of the annual CO2 variations obtained for two larch discs shows that an unfavorable habitat (e.g., very dry climate) can change the sign of the annual CO2 trends in tree rings. Thus, it may be concluded that environmental changes can influence stem respired CO2 through changes in the cyclicity. Moreover, it can be assumed that atmospheric CO2 rise and elevated surface temperatures observed since 1960 have changed the annual diffusion pattern of stem CO2 and caused it to accumulate.

Acknowledgments 17 • This work was supported by the Siberian Branch of the Russian Academy of Sciences (Project VII.66.1.3). • We would like to thank the staff of Laboratory of Isotope Organic Geochemistry (Tomsk, Russia) for performing an isotope analysis . • We would also like to express sincere thanks to N. P. Baidin, director of Tomsk Forest Museum, for a 300-year old larch disc, and • Dr. T. Chesnokova for CO2,H2O spectra calculations.